diff --git a/boards/pic32cz_curiosity_ultra/Makefile.inc b/boards/pic32cz_curiosity_ultra/Makefile.inc
index a867497..cd71bab 100644
--- a/boards/pic32cz_curiosity_ultra/Makefile.inc
+++ b/boards/pic32cz_curiosity_ultra/Makefile.inc
@@ -9,7 +9,11 @@ OBJCOPY = $(GCC_PATH)arm-none-eabi-objcopy
 
 CFLAGS += -Wall -Werror $(INCLUDE) -g3 \
           -ffreestanding -nostdlib -mcpu=cortex-m7 \
-          -DPLATFORM_PIC32CZ -MMD -MP
+          -DPLATFORM_PIC32CZ -MMD -MP \
+          -DWHAL_CFG_GPIO_API_MAPPING_PIC32CZ \
+          -DWHAL_CFG_CLOCK_API_MAPPING_PIC32CZ_PLL \
+          -DWHAL_CFG_UART_API_MAPPING_PIC32CZ \
+          -DWHAL_CFG_SUPPLY_API_MAPPING_PIC32CZ
 LDFLAGS = --omagic -static
 
 LINKER_SCRIPT ?= $(_BOARD_DIR)/linker.ld
@@ -19,11 +23,7 @@ INCLUDE += -I$(_BOARD_DIR) -I$(WHAL_DIR)/boards/peripheral
 BOARD_SOURCE = $(_BOARD_DIR)/ivt.c
 BOARD_SOURCE += $(_BOARD_DIR)/board.c
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/gpio.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/clock.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/uart.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/timer.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/supply.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/flash.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/rng.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/block.c)
diff --git a/boards/pic32cz_curiosity_ultra/board.c b/boards/pic32cz_curiosity_ultra/board.c
index c66d209..d94749f 100644
--- a/boards/pic32cz_curiosity_ultra/board.c
+++ b/boards/pic32cz_curiosity_ultra/board.c
@@ -8,12 +8,14 @@
 
 /* Supply */
 static whal_Supply g_whalSupply = {
-    WHAL_PIC32CZ_SUPPLY_DEVICE,
+    .regmap = { WHAL_PIC32CZ_SUPPLY_REGMAP },
+    /* .driver: direct API mapping */
 };
 
 /* Clock */
 whal_Clock g_whalClock = {
-    WHAL_PIC32CZ_CLOCK_PLL_DEVICE,
+    .regmap = { WHAL_PIC32CZ_CLOCK_PLL_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Pic32czClock_Cfg) {
         /* 300MHz clock */
@@ -60,7 +62,8 @@ static const whal_Pic32czClock_Clk g_peripheralClocks[] = {
 
 /* GPIO */
 whal_Gpio g_whalGpio = {
-    WHAL_PIC32CZ_GPIO_DEVICE,
+    .regmap = { WHAL_PIC32CZ_GPIO_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Pic32czGpio_Cfg) {
         .pinCfgCount = 3,
@@ -89,7 +92,8 @@ whal_Gpio g_whalGpio = {
 
 /* UART */
 whal_Uart g_whalUart = {
-    WHAL_PIC32CZ_SERCOM4_UART_DEVICE,
+    .regmap = { WHAL_PIC32CZ_SERCOM4_UART_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Pic32czUart_Cfg) {
         .baud = WHAL_PIC32CZ_UART_BAUD(115200, 300000000),
@@ -100,7 +104,8 @@ whal_Uart g_whalUart = {
 
 /* Timer */
 whal_Timer g_whalTimer = {
-    WHAL_CORTEX_M7_SYSTICK_DEVICE,
+    .regmap = { WHAL_CORTEX_M7_SYSTICK_REGMAP },
+    .driver = WHAL_CORTEX_M7_SYSTICK_DRIVER,
 
     .cfg = &(whal_SysTick_Cfg) {
         .cyclesPerTick = 300000000 / 1000,
@@ -111,7 +116,8 @@ whal_Timer g_whalTimer = {
 
 /* Flash */
 whal_Flash g_whalFlash = {
-    WHAL_PIC32CZ_FLASH_DEVICE,
+    .regmap = { WHAL_PIC32CZ_FLASH_REGMAP },
+    .driver = WHAL_PIC32CZ_FLASH_DRIVER,
 };
 
 /* SysTick timing */
diff --git a/boards/stm32c031_nucleo/Makefile.inc b/boards/stm32c031_nucleo/Makefile.inc
index 4d1985f..b54d517 100644
--- a/boards/stm32c031_nucleo/Makefile.inc
+++ b/boards/stm32c031_nucleo/Makefile.inc
@@ -9,7 +9,11 @@ OBJCOPY = $(GCC_PATH)arm-none-eabi-objcopy
 
 CFLAGS += -Wall -Werror $(INCLUDE) -g3 \
           -ffreestanding -nostdlib -mcpu=cortex-m0plus -mthumb \
-          -DPLATFORM_STM32C0 -MMD -MP
+          -DPLATFORM_STM32C0 -MMD -MP \
+          -DWHAL_CFG_GPIO_API_MAPPING_STM32C0 \
+          -DWHAL_CFG_CLOCK_API_MAPPING_STM32C0 \
+          -DWHAL_CFG_UART_API_MAPPING_STM32C0 \
+          -DWHAL_CFG_SPI_API_MAPPING_STM32C0
 LDFLAGS = -mcpu=cortex-m0plus -mthumb -ffreestanding -nostartfiles \
           -Wl,--omagic -static
 
@@ -20,13 +24,9 @@ INCLUDE += -I$(_BOARD_DIR) -I$(WHAL_DIR)/boards/peripheral
 BOARD_SOURCE = $(_BOARD_DIR)/ivt.c
 BOARD_SOURCE += $(_BOARD_DIR)/board.c
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/gpio.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/clock.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/uart.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/timer.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/supply.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/flash.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/spi.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/rng.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/crypto.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/block.c)
diff --git a/boards/stm32c031_nucleo/board.c b/boards/stm32c031_nucleo/board.c
index 15c1592..8cbf426 100644
--- a/boards/stm32c031_nucleo/board.c
+++ b/boards/stm32c031_nucleo/board.c
@@ -32,7 +32,8 @@ whal_Timeout g_whalTimeout = {
 
 /* Clock */
 whal_Clock g_whalClock = {
-    WHAL_STM32C031_RCC_DEVICE,
+    .regmap = { WHAL_STM32C031_RCC_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32c0Rcc_Cfg) {
         .hsidiv = WHAL_STM32C0_RCC_HSIDIV_1, /* HSI48 / 1 = 48 MHz */
@@ -50,7 +51,8 @@ static const whal_Stm32c0Rcc_Clk g_clocks[] = {
 
 /* GPIO */
 whal_Gpio g_whalGpio = {
-    WHAL_STM32C031_GPIO_DEVICE,
+    .regmap = { WHAL_STM32C031_GPIO_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32c0Gpio_Cfg) {
         .pinCfg = (whal_Stm32c0Gpio_PinCfg[PIN_COUNT]) {
@@ -91,7 +93,8 @@ whal_Gpio g_whalGpio = {
 
 /* Timer */
 whal_Timer g_whalTimer = {
-    WHAL_CORTEX_M0PLUS_SYSTICK_DEVICE,
+    .regmap = { WHAL_CORTEX_M0PLUS_SYSTICK_REGMAP },
+    .driver = WHAL_CORTEX_M0PLUS_SYSTICK_DRIVER,
 
     .cfg = &(whal_SysTick_Cfg) {
         .cyclesPerTick = 48000000 / 1000, /* 48 MHz / 1 kHz = 1 ms tick */
@@ -102,7 +105,8 @@ whal_Timer g_whalTimer = {
 
 /* UART */
 whal_Uart g_whalUart = {
-    WHAL_STM32C031_USART1_DEVICE,
+    .regmap = { WHAL_STM32C031_USART1_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32c0Uart_Cfg) {
         .timeout = &g_whalTimeout,
@@ -112,7 +116,8 @@ whal_Uart g_whalUart = {
 
 /* SPI */
 whal_Spi g_whalSpi = {
-    WHAL_STM32C031_SPI1_DEVICE,
+    .regmap = { WHAL_STM32C031_SPI1_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32c0Spi_Cfg) {
         .pclk = 48000000,
@@ -122,7 +127,8 @@ whal_Spi g_whalSpi = {
 
 /* Flash */
 whal_Flash g_whalFlash = {
-    WHAL_STM32C031_FLASH_DEVICE,
+    .regmap = { WHAL_STM32C031_FLASH_REGMAP },
+    .driver = WHAL_STM32C031_FLASH_DRIVER,
 
     .cfg = &(whal_Stm32c0Flash_Cfg) {
         .startAddr = 0x08000000,
diff --git a/boards/stm32f411_blackpill/Makefile.inc b/boards/stm32f411_blackpill/Makefile.inc
index bc8122f..6509c02 100644
--- a/boards/stm32f411_blackpill/Makefile.inc
+++ b/boards/stm32f411_blackpill/Makefile.inc
@@ -10,7 +10,11 @@ OBJCOPY = $(GCC_PATH)arm-none-eabi-objcopy
 CFLAGS += -Wall -Werror $(INCLUDE) -g3 \
           -ffreestanding -nostdlib -mcpu=cortex-m4 -mfloat-abi=hard \
           -mfpu=fpv4-sp-d16 -mthumb \
-          -DPLATFORM_STM32F4 -MMD -MP
+          -DPLATFORM_STM32F4 -MMD -MP \
+          -DWHAL_CFG_GPIO_API_MAPPING_STM32F4 \
+          -DWHAL_CFG_CLOCK_API_MAPPING_STM32F4_PLL \
+          -DWHAL_CFG_UART_API_MAPPING_STM32F4 \
+          -DWHAL_CFG_SPI_API_MAPPING_STM32F4
 LDFLAGS = --omagic -static
 
 LINKER_SCRIPT ?= $(_BOARD_DIR)/linker.ld
@@ -20,13 +24,9 @@ INCLUDE += -I$(_BOARD_DIR) -I$(WHAL_DIR)/boards/peripheral
 BOARD_SOURCE = $(_BOARD_DIR)/ivt.c
 BOARD_SOURCE += $(_BOARD_DIR)/board.c
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/gpio.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/clock.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/uart.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/timer.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/supply.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/flash.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/spi.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/rng.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/crypto.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/block.c)
diff --git a/boards/stm32f411_blackpill/board.c b/boards/stm32f411_blackpill/board.c
index 6fd5a6b..abbfd39 100644
--- a/boards/stm32f411_blackpill/board.c
+++ b/boards/stm32f411_blackpill/board.c
@@ -39,7 +39,8 @@ static const whal_Stm32f4Flash_Sector g_flashSectors[] = {
 
 /* Clock */
 whal_Clock g_whalClock = {
-    WHAL_STM32F411_RCC_PLL_DEVICE,
+    .regmap = { WHAL_STM32F411_RCC_PLL_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32f4Rcc_Cfg) {
         .sysClkSrc = WHAL_STM32F4_RCC_SYSCLK_SRC_PLL,
@@ -66,7 +67,8 @@ static const whal_Stm32f4Rcc_Clk g_clocks[] = {
 
 /* GPIO */
 whal_Gpio g_whalGpio = {
-    WHAL_STM32F411_GPIO_DEVICE,
+    .regmap = { WHAL_STM32F411_GPIO_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32f4Gpio_Cfg) {
         .pinCfg = (whal_Stm32f4Gpio_PinCfg[PIN_COUNT]) {
@@ -107,7 +109,8 @@ whal_Gpio g_whalGpio = {
 
 /* Timer */
 whal_Timer g_whalTimer = {
-    WHAL_CORTEX_M4_SYSTICK_DEVICE,
+    .regmap = { WHAL_CORTEX_M4_SYSTICK_REGMAP },
+    .driver = WHAL_CORTEX_M4_SYSTICK_DRIVER,
 
     .cfg = &(whal_SysTick_Cfg) {
         .cyclesPerTick = 100000000 / 1000, /* 100 MHz / 1 kHz = 1 ms tick */
@@ -118,7 +121,8 @@ whal_Timer g_whalTimer = {
 
 /* UART */
 whal_Uart g_whalUart = {
-    WHAL_STM32F411_USART2_DEVICE,
+    .regmap = { WHAL_STM32F411_USART2_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32f4Uart_Cfg) {
         .timeout = &g_whalTimeout,
@@ -128,7 +132,8 @@ whal_Uart g_whalUart = {
 
 /* SPI */
 whal_Spi g_whalSpi = {
-    WHAL_STM32F411_SPI1_DEVICE,
+    .regmap = { WHAL_STM32F411_SPI1_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32f4Spi_Cfg) {
         .pclk = 100000000,
@@ -138,7 +143,8 @@ whal_Spi g_whalSpi = {
 
 /* Flash */
 whal_Flash g_whalFlash = {
-    WHAL_STM32F411_FLASH_DEVICE,
+    .regmap = { WHAL_STM32F411_FLASH_REGMAP },
+    .driver = WHAL_STM32F411_FLASH_DRIVER,
 
     .cfg = &(whal_Stm32f4Flash_Cfg) {
         .startAddr = 0x08000000,
diff --git a/boards/stm32h563zi_nucleo/Makefile.inc b/boards/stm32h563zi_nucleo/Makefile.inc
index 92cfc6e..b641425 100644
--- a/boards/stm32h563zi_nucleo/Makefile.inc
+++ b/boards/stm32h563zi_nucleo/Makefile.inc
@@ -9,7 +9,14 @@ OBJCOPY = $(GCC_PATH)arm-none-eabi-objcopy
 
 CFLAGS += -Wall -Werror $(INCLUDE) -g3 \
           -ffreestanding -nostdlib -mcpu=cortex-m33 \
-          -DPLATFORM_STM32H5 -MMD -MP
+          -DPLATFORM_STM32H5 -MMD -MP \
+          -DWHAL_CFG_GPIO_API_MAPPING_STM32H5 \
+          -DWHAL_CFG_CLOCK_API_MAPPING_STM32H5_PLL \
+          -DWHAL_CFG_UART_API_MAPPING_STM32H5 \
+          -DWHAL_CFG_SPI_API_MAPPING_STM32H5 \
+          -DWHAL_CFG_RNG_API_MAPPING_STM32H5 \
+          -DWHAL_CFG_ETH_API_MAPPING_STM32H5 \
+          -DWHAL_CFG_ETH_PHY_API_MAPPING_LAN8742A
 LDFLAGS = --omagic -static
 
 LINKER_SCRIPT ?= $(_BOARD_DIR)/linker.ld
@@ -19,19 +26,13 @@ INCLUDE += -I$(_BOARD_DIR) -I$(WHAL_DIR)/boards/peripheral
 BOARD_SOURCE = $(_BOARD_DIR)/ivt.c
 BOARD_SOURCE += $(_BOARD_DIR)/board.c
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/gpio.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/clock.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/uart.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/timer.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/supply.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/flash.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/spi.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/rng.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/crypto.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/block.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/eth.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/eth_phy/*.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/stm32h5_*.c)
+BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/lan8742a_*.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/systick.c)
 
 # Peripheral devices
diff --git a/boards/stm32h563zi_nucleo/board.c b/boards/stm32h563zi_nucleo/board.c
index ab28f37..5ea8557 100644
--- a/boards/stm32h563zi_nucleo/board.c
+++ b/boards/stm32h563zi_nucleo/board.c
@@ -27,7 +27,8 @@ whal_Timeout g_whalTimeout = {
 
 /* Clock */
 whal_Clock g_whalClock = {
-    WHAL_STM32H563_RCC_PLL_DEVICE,
+    .regmap = { WHAL_STM32H563_RCC_PLL_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32h5Rcc_Cfg) {
         .sysClkSrc = WHAL_STM32H5_RCC_SYSCLK_SRC_PLL1,
@@ -65,7 +66,8 @@ static const whal_Stm32h5Rcc_Clk g_ethClocks[] = {
 
 /* GPIO */
 whal_Gpio g_whalGpio = {
-    WHAL_STM32H563_GPIO_DEVICE,
+    .regmap = { WHAL_STM32H563_GPIO_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32h5Gpio_Cfg) {
         .pinCfg = (whal_Stm32h5Gpio_PinCfg[PIN_COUNT]) {
@@ -156,7 +158,8 @@ whal_Gpio g_whalGpio = {
 
 /* Timer */
 whal_Timer g_whalTimer = {
-    WHAL_CORTEX_M33_SYSTICK_DEVICE,
+    .regmap = { WHAL_CORTEX_M33_SYSTICK_REGMAP },
+    .driver = WHAL_CORTEX_M33_SYSTICK_DRIVER,
 
     .cfg = &(whal_SysTick_Cfg) {
         .cyclesPerTick = 168000000 / 1000, /* 168 MHz / 1 kHz = 1 ms tick */
@@ -167,7 +170,8 @@ whal_Timer g_whalTimer = {
 
 /* UART */
 whal_Uart g_whalUart = {
-    WHAL_STM32H563_USART2_DEVICE,
+    .regmap = { WHAL_STM32H563_USART2_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32h5Uart_Cfg) {
         .timeout = &g_whalTimeout,
@@ -177,7 +181,8 @@ whal_Uart g_whalUart = {
 
 /* SPI */
 whal_Spi g_whalSpi = {
-    WHAL_STM32H563_SPI1_DEVICE,
+    .regmap = { WHAL_STM32H563_SPI1_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32h5Spi_Cfg) {
         .pclk = 168000000,
@@ -187,7 +192,8 @@ whal_Spi g_whalSpi = {
 
 /* RNG */
 whal_Rng g_whalRng = {
-    WHAL_STM32H563_RNG_DEVICE,
+    .regmap = { WHAL_STM32H563_RNG_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32h5Rng_Cfg) {
         .timeout = &g_whalTimeout,
@@ -197,7 +203,8 @@ whal_Rng g_whalRng = {
 
 /* Flash */
 whal_Flash g_whalFlash = {
-    WHAL_STM32H563_FLASH_DEVICE,
+    .regmap = { WHAL_STM32H563_FLASH_REGMAP },
+    .driver = WHAL_STM32H563_FLASH_DRIVER,
 
     .cfg = &(whal_Stm32h5Flash_Cfg) {
         .startAddr = 0x08000000,
@@ -222,7 +229,8 @@ static uint8_t ethRxBufs[ETH_RX_DESC_COUNT * ETH_RX_BUF_SIZE]
     __attribute__((aligned(4)));
 
 whal_Eth g_whalEth = {
-    WHAL_STM32H563_ETH_DEVICE,
+    .regmap = { WHAL_STM32H563_ETH_REGMAP },
+    /* .driver: direct API mapping */
 
     .macAddr = {0x00, 0x80, 0xE1, 0x00, 0x00, 0x01},
     .cfg = &(whal_Stm32h5Eth_Cfg) {
@@ -242,7 +250,7 @@ whal_Eth g_whalEth = {
 whal_EthPhy g_whalEthPhy = {
     .eth = &g_whalEth,
     .addr = BOARD_ETH_PHY_ADDR,
-    .driver = &whal_Lan8742a_Driver,
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Lan8742a_Cfg) {
         .timeout = &g_whalTimeout,
diff --git a/boards/stm32wb55xx_nucleo/Makefile.inc b/boards/stm32wb55xx_nucleo/Makefile.inc
index d6916c0..7aa7748 100644
--- a/boards/stm32wb55xx_nucleo/Makefile.inc
+++ b/boards/stm32wb55xx_nucleo/Makefile.inc
@@ -12,7 +12,15 @@ CFLAGS += -Wall -Werror $(INCLUDE) -g3 \
           -DPLATFORM_STM32WB -MMD -MP \
           $(if $(DMA),-DBOARD_DMA) \
           $(if $(filter iwdg,$(WATCHDOG)),-DBOARD_WATCHDOG_IWDG) \
-          $(if $(filter wwdg,$(WATCHDOG)),-DBOARD_WATCHDOG_WWDG)
+          $(if $(filter wwdg,$(WATCHDOG)),-DBOARD_WATCHDOG_WWDG) \
+          $(if $(DMA),-DWHAL_CFG_UART_API_MAPPING_STM32WB_DMA,-DWHAL_CFG_UART_API_MAPPING_STM32WB) \
+          -DWHAL_CFG_GPIO_API_MAPPING_STM32WB \
+          -DWHAL_CFG_SPI_API_MAPPING_STM32WB \
+          -DWHAL_CFG_I2C_API_MAPPING_STM32WB \
+          -DWHAL_CFG_CLOCK_API_MAPPING_STM32WB_PLL \
+          -DWHAL_CFG_RNG_API_MAPPING_STM32WB \
+          -DWHAL_CFG_DMA_API_MAPPING_STM32WB \
+          -DWHAL_CFG_CRYPTO_API_MAPPING_STM32WB_AES
 LDFLAGS = --omagic -static
 
 LINKER_SCRIPT ?= $(_BOARD_DIR)/linker.ld
@@ -22,20 +30,13 @@ INCLUDE += -I$(_BOARD_DIR) -I$(WHAL_DIR)/boards/peripheral
 BOARD_SOURCE = $(_BOARD_DIR)/ivt.c
 BOARD_SOURCE += $(_BOARD_DIR)/board.c
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/gpio.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/clock.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/uart.c)
+BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/crypto.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/timer.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/supply.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/flash.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/spi.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/i2c.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/sensor.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/watchdog.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/rng.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/crypto.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/block.c)
-BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/dma.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/irq.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/irq/cortex_m4_nvic.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/stm32wb_*.c)
diff --git a/boards/stm32wb55xx_nucleo/board.c b/boards/stm32wb55xx_nucleo/board.c
index 43c6987..b1a909a 100644
--- a/boards/stm32wb55xx_nucleo/board.c
+++ b/boards/stm32wb55xx_nucleo/board.c
@@ -27,12 +27,14 @@ whal_Timeout g_whalTimeout = {
 
 /* IRQ */
 whal_Irq g_whalIrq = {
-    WHAL_CORTEX_M4_NVIC_DEVICE,
+    .regmap = { WHAL_CORTEX_M4_NVIC_REGMAP },
+    .driver = WHAL_CORTEX_M4_NVIC_DRIVER,
 };
 
 /* Clock */
 whal_Clock g_whalClock = {
-    WHAL_STM32WB55_RCC_PLL_DEVICE,
+    .regmap = { WHAL_STM32WB55_RCC_PLL_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32wbRcc_Cfg) {
         .sysClkSrc = WHAL_STM32WB_RCC_SYSCLK_SRC_PLL,
@@ -67,7 +69,8 @@ static const whal_Stm32wbRcc_Clk g_clocks[] = {
 
 /* GPIO */
 whal_Gpio g_whalGpio = {
-    WHAL_STM32WB55_GPIO_DEVICE,
+    .regmap = { WHAL_STM32WB55_GPIO_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32wbGpio_Cfg) {
         .pinCfg = (whal_Stm32wbGpio_PinCfg[PIN_COUNT]) {
@@ -123,7 +126,8 @@ whal_Gpio g_whalGpio = {
 
 /* I2C */
 whal_I2c g_whalI2c = {
-    WHAL_STM32WB55_I2C1_DEVICE,
+    .regmap = { WHAL_STM32WB55_I2C1_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32wbI2c_Cfg) {
         .pclk = 64000000,
@@ -133,7 +137,8 @@ whal_I2c g_whalI2c = {
 
 /* SPI */
 whal_Spi g_whalSpi = {
-    WHAL_STM32WB55_SPI1_DEVICE,
+    .regmap = { WHAL_STM32WB55_SPI1_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32wbSpi_Cfg) {
         .pclk = 64000000,
@@ -143,7 +148,8 @@ whal_Spi g_whalSpi = {
 
 /* Timer */
 whal_Timer g_whalTimer = {
-    WHAL_CORTEX_M4_SYSTICK_DEVICE,
+    .regmap = { WHAL_CORTEX_M4_SYSTICK_REGMAP },
+    .driver = WHAL_CORTEX_M4_SYSTICK_DRIVER,
 
     .cfg = &(whal_SysTick_Cfg) {
         .cyclesPerTick = 64000000 / 1000,
@@ -156,7 +162,8 @@ whal_Timer g_whalTimer = {
 #ifdef BOARD_DMA
 
 whal_Dma g_whalDma1 = {
-    WHAL_STM32WB55_DMA1_DEVICE,
+    .regmap = { WHAL_STM32WB55_DMA1_REGMAP },
+    /* .driver: direct API mapping */
     .cfg = &(whal_Stm32wbDma_Cfg){WHAL_STM32WB55_DMA1_CFG},
 };
 
@@ -179,8 +186,8 @@ void DMA1_Channel5_IRQHandler(void)
 /* UART */
 #ifdef BOARD_DMA
 whal_Uart g_whalUart = {
-    WHAL_STM32WB55_UART1_DEVICE,
-    .driver = &whal_Stm32wbUartDma_Driver,
+    .regmap = { WHAL_STM32WB55_UART1_REGMAP },
+    /* .driver: direct API mapping */
     .cfg = &(whal_Stm32wbUartDma_Cfg) {
         .base = {
             .brr = WHAL_STM32WB_UART_BRR(64000000, 115200),
@@ -195,7 +202,8 @@ whal_Uart g_whalUart = {
 };
 #else
 whal_Uart g_whalUart = {
-    WHAL_STM32WB55_UART1_DEVICE,
+    .regmap = { WHAL_STM32WB55_UART1_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32wbUart_Cfg) {
         .timeout = &g_whalTimeout,
@@ -207,7 +215,8 @@ whal_Uart g_whalUart = {
 
 /* Flash */
 whal_Flash g_whalFlash = {
-    WHAL_STM32WB55_FLASH_DEVICE,
+    .regmap = { WHAL_STM32WB55_FLASH_REGMAP },
+    .driver = WHAL_STM32WB55_FLASH_DRIVER,
 
     .cfg = &(whal_Stm32wbFlash_Cfg) {
         .timeout = &g_whalTimeout,
@@ -219,7 +228,8 @@ whal_Flash g_whalFlash = {
 
 /* RNG */
 whal_Rng g_whalRng = {
-    WHAL_STM32WB55_RNG_DEVICE,
+    .regmap = { WHAL_STM32WB55_RNG_REGMAP },
+    /* .driver: direct API mapping */
 
     .cfg = &(whal_Stm32wbRng_Cfg) {
         .timeout = &g_whalTimeout,
@@ -237,7 +247,8 @@ static const whal_Crypto_OpFunc cryptoOps[BOARD_CRYPTO_OP_COUNT] = {
 };
 
 whal_Crypto g_whalCrypto = {
-    WHAL_STM32WB55_AES1_DEVICE,
+    .regmap = { WHAL_STM32WB55_AES1_REGMAP },
+    /* .driver: direct API mapping */
 
     .ops = cryptoOps,
     .opsCount = BOARD_CRYPTO_OP_COUNT,
@@ -249,7 +260,8 @@ whal_Crypto g_whalCrypto = {
 
 #ifdef BOARD_WATCHDOG_IWDG
 whal_Watchdog g_whalWatchdog = {
-    WHAL_STM32WB55_IWDG_DEVICE,
+    .regmap = { WHAL_STM32WB55_IWDG_REGMAP },
+    .driver = WHAL_STM32WB55_IWDG_DRIVER,
 
     .cfg = &(whal_Stm32wbIwdg_Cfg) {
         .prescaler = WHAL_STM32WB_IWDG_PR_32,
@@ -259,7 +271,8 @@ whal_Watchdog g_whalWatchdog = {
 };
 #elif defined(BOARD_WATCHDOG_WWDG)
 whal_Watchdog g_whalWatchdog = {
-    WHAL_STM32WB55_WWDG_DEVICE,
+    .regmap = { WHAL_STM32WB55_WWDG_REGMAP },
+    .driver = WHAL_STM32WB55_WWDG_DRIVER,
 
     .cfg = &(whal_Stm32wbWwdg_Cfg) {
         .prescaler = WHAL_STM32WB_WWDG_TB_128,
diff --git a/docs/adding_a_board.md b/docs/adding_a_board.md
index 229e163..2750a76 100644
--- a/docs/adding_a_board.md
+++ b/docs/adding_a_board.md
@@ -59,7 +59,7 @@ static whal_MyplatformGpio_Cfg gpioConfig = {
 };
 
 whal_Gpio g_whalGpio = {
-    WHAL_MYPLATFORM_GPIO_DEVICE,
+    .regmap = { WHAL_MYPLATFORM_GPIO_REGMAP },
     .cfg = &gpioConfig,
 };
 
@@ -156,7 +156,10 @@ GCC     = arm-none-eabi-gcc
 LD      = arm-none-eabi-gcc
 OBJCOPY = arm-none-eabi-objcopy
 
-CFLAGS  = -mcpu=cortex-m4 -mthumb -Os -Wall -MMD $(INCLUDE) -I$(_BOARD_DIR)
+CFLAGS  = -mcpu=cortex-m4 -mthumb -Os -Wall -MMD $(INCLUDE) -I$(_BOARD_DIR) \
+          -DWHAL_CFG_GPIO_API_MAPPING_MYPLATFORM \
+          -DWHAL_CFG_CLOCK_API_MAPPING_MYPLATFORM_PLL \
+          -DWHAL_CFG_UART_API_MAPPING_MYPLATFORM
 LDFLAGS = -mcpu=cortex-m4 -mthumb -nostdlib -lgcc
 
 LINKER_SCRIPT = $(_BOARD_DIR)/linker.ld
@@ -165,8 +168,14 @@ INCLUDE += -I$(_BOARD_DIR) -I$(WHAL_DIR)/boards/peripheral
 
 BOARD_SOURCE  = $(_BOARD_DIR)/board.c
 BOARD_SOURCE += $(_BOARD_DIR)/ivt.c
+BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*.c)
+# Dispatch sources for mapped types are excluded; keep dispatch sources
+# for types that may have peripheral drivers (flash, block, sensor).
+BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/timer.c)
+BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/flash.c)
+BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/block.c)
 BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/myplatform_*.c)
-BOARD_SOURCE += $(WHAL_DIR)/src/timer/systick.c
+BOARD_SOURCE += $(wildcard $(WHAL_DIR)/src/*/systick.c)
 
 # Peripheral devices
 include $(WHAL_DIR)/boards/peripheral/Makefile.inc
diff --git a/docs/getting_started.md b/docs/getting_started.md
index 57dfdd8..2365706 100644
--- a/docs/getting_started.md
+++ b/docs/getting_started.md
@@ -75,18 +75,22 @@ struct whal_Gpio {
 - **cfg** — points to a platform-specific configuration struct that the driver
   reads during Init
 
-Platform headers provide device macros that fill in the `regmap` and `driver`
-fields, so you only need to provide the `cfg`:
+Platform headers provide `_REGMAP` and `_DRIVER` macros for each peripheral,
+so you only need to fill in the `cfg`:
 
 ```c
 #include <wolfHAL/platform/st/stm32wb55xx.h>
 
 whal_Gpio g_whalGpio = {
-    WHAL_STM32WB55_GPIO_DEVICE,
+    .regmap = { WHAL_STM32WB55_GPIO_REGMAP },
+    .driver = WHAL_STM32WB55_GPIO_DRIVER,
     .cfg = &gpioConfig,
 };
 ```
 
+When direct API mapping is active for a device type, the `.driver` field is
+omitted since calls go directly to the driver implementation.
+
 ## Configuring Peripherals
 
 Each platform driver defines its own configuration struct with the parameters
@@ -95,7 +99,8 @@ and a pin configuration table:
 
 ```c
 whal_Gpio g_whalGpio = {
-    WHAL_STM32WB55_GPIO_DEVICE,
+    .regmap = { WHAL_STM32WB55_GPIO_REGMAP },
+    .driver = WHAL_STM32WB55_GPIO_DRIVER,
 
     .cfg = &(whal_Stm32wbGpio_Cfg) {
         .pinCfg = (whal_Stm32wbGpio_PinCfg[]) {
@@ -116,7 +121,8 @@ A UART driver might need a pre-computed baud rate register value and a timeout:
 
 ```c
 whal_Uart g_whalUart = {
-    WHAL_STM32WB55_UART1_DEVICE,
+    .regmap = { WHAL_STM32WB55_UART1_REGMAP },
+    .driver = WHAL_STM32WB55_UART1_DRIVER,
 
     .cfg = &(whal_Stm32wbUart_Cfg) {
         .timeout = &g_whalTimeout,
@@ -220,10 +226,11 @@ operation completed. The error codes are:
 | Code | Meaning |
 |------|---------|
 | `WHAL_SUCCESS` | Operation completed successfully |
-| `WHAL_EINVAL` | Invalid argument or unsupported operation |
+| `WHAL_EINVAL` | Invalid argument (null device pointer, null data pointer) |
 | `WHAL_ENOTREADY` | Resource is busy or not yet available |
 | `WHAL_EHARDWARE` | Hardware error (e.g., RNG entropy failure) |
 | `WHAL_ETIMEOUT` | Operation timed out waiting for hardware |
+| `WHAL_ENOTIMPL` | Operation not implemented by this driver |
 
 ## Optimizing for Size
 
@@ -236,6 +243,33 @@ Define `WHAL_CFG_DIRECT_CALLBACKS` to bypass the generic dispatch layer. API
 calls compile down to direct function pointer calls with no input validation,
 eliminating the dispatch source files entirely.
 
+### Direct API Mapping
+
+Each platform driver source provides an `#ifdef` block that renames its
+driver functions to the top-level API names. When the corresponding
+`WHAL_CFG_<TYPE>_API_MAPPING_<VARIANT>` flag is defined, the driver file
+itself provides the definition of the top-level API — no wrapper, no vtable
+indirection, no runtime null-check.
+
+For example, `-DWHAL_CFG_UART_API_MAPPING_STM32WB` causes
+`src/uart/stm32wb_uart.c` to emit external symbols named `whal_Uart_Init`,
+`whal_Uart_Deinit`, `whal_Uart_Send`, and `whal_Uart_Recv`, each bound to
+the polled STM32WB UART driver body. Application code calling
+`whal_Uart_Send(&dev, buf, sz)` links directly to the platform driver.
+
+All boards enable direct API mapping unconditionally for device types that
+have only one driver in the build. Device types where a peripheral driver
+could coexist (flash, block, sensor) are not mapped — they keep the vtable
+dispatch so multiple drivers can be linked simultaneously.
+
+**The dispatch source `src/<type>/<type>.c` must not be compiled when the
+corresponding mapping flag is active.** Both the dispatch source and the
+mapped driver source provide the same top-level symbols, which would cause
+a multiple-definition link error. Exclude the dispatch source from the
+board's source list.
+
+Only one mapping flag may be active per device type per build.
+
 ### Custom Vtables
 
 The platform drivers provide a pre-built vtable with all operations populated.
@@ -247,7 +281,7 @@ static const whal_GpioDriver myGpioDriver = {
     .Init   = whal_Stm32wbGpio_Init,
     .Deinit = whal_Stm32wbGpio_Deinit,
     .Set    = whal_Stm32wbGpio_Set,
-    /* Get left as NULL — not needed, saves pulling in that code */
+    /* Get left as NULL — calls return WHAL_ENOTIMPL, saves pulling in that code */
 };
 
 whal_Gpio g_whalGpio = {
diff --git a/docs/writing_a_driver.md b/docs/writing_a_driver.md
index 02a9db8..bb75854 100644
--- a/docs/writing_a_driver.md
+++ b/docs/writing_a_driver.md
@@ -61,6 +61,41 @@ const whal_FooDriver whal_MyplatformFoo_Driver = {
 };
 ```
 
+### Direct API Mapping
+
+Every driver should include a rename-at-definition block that lets the build
+system map chip-specific function names to the top-level API. Place this
+`#ifdef` block after your register defines and before the first function
+definition:
+
+```c
+#ifdef WHAL_CFG_FOO_API_MAPPING_MYPLATFORM
+#define whal_MyplatformFoo_Init   whal_Foo_Init
+#define whal_MyplatformFoo_Deinit whal_Foo_Deinit
+/* ... one #define per mapped function ... */
+#endif
+```
+
+When the flag is defined, the preprocessor renames each function to its
+generic API name at the definition site. The driver source uses chip-specific
+names everywhere — the macros handle the rest.
+
+Wrap the vtable in `#ifndef` since it is unused when mapping is active:
+
+```c
+#ifndef WHAL_CFG_FOO_API_MAPPING_MYPLATFORM
+const whal_FooDriver whal_MyplatformFoo_Driver = {
+    .Init   = whal_MyplatformFoo_Init,
+    .Deinit = whal_MyplatformFoo_Deinit,
+};
+#endif
+```
+
+In the chip header, wrap the mapped function prototypes and extern vtable
+declaration in the same `#ifndef` guard. Types and configuration structs
+stay unconditional. Extension functions (`Ext_*`) that have no generic
+equivalent are never mapped and stay unconditional.
+
 ### Configuration
 
 The device struct's `cfg` field points to your platform-specific configuration.
@@ -238,7 +273,9 @@ platform that re-export the existing driver under platform-specific names.
 #### Header
 
 The alias header `typedef`s the config structs and `#define`s the driver
-instance, functions, and any enum constants:
+instance, functions, and any enum constants. The driver and function aliases
+are wrapped in `#ifndef` so they are omitted when direct API mapping is active
+for the alias platform:
 
 ```c
 #ifndef WHAL_STM32H5_GPIO_H
@@ -249,11 +286,13 @@ instance, functions, and any enum constants:
 typedef whal_Stm32wbGpio_Cfg    whal_Stm32h5Gpio_Cfg;
 typedef whal_Stm32wbGpio_PinCfg whal_Stm32h5Gpio_PinCfg;
 
+#ifndef WHAL_CFG_GPIO_API_MAPPING_STM32H5
 #define whal_Stm32h5Gpio_Driver whal_Stm32wbGpio_Driver
 #define whal_Stm32h5Gpio_Init   whal_Stm32wbGpio_Init
 #define whal_Stm32h5Gpio_Deinit whal_Stm32wbGpio_Deinit
 #define whal_Stm32h5Gpio_Get    whal_Stm32wbGpio_Get
 #define whal_Stm32h5Gpio_Set    whal_Stm32wbGpio_Set
+#endif
 
 /* Re-export enum constants under the new platform name */
 #define WHAL_STM32H5_GPIO_MODE_OUT WHAL_STM32WB_GPIO_MODE_OUT
@@ -288,18 +327,32 @@ field, different reset value that affects behavior), write a new driver. A
 partial alias that papers over register differences with workarounds is worse
 than a clean separate implementation.
 
-### Platform Device Macro
+### Platform Device Macros
 
-Add a device macro to your platform header
+Add regmap and driver macros to your platform header
 (`wolfHAL/platform/<vendor>/<device>.h`) so that board configs can instantiate
 devices without knowing the register addresses or driver symbols:
 
 ```c
-#define WHAL_MYPLATFORM_FOO_DEVICE \
-    .regmap = { .base = 0x40000000, .size = 0x400 }, \
-    .driver = &whal_MyplatformFoo_Driver
+#define WHAL_MYPLATFORM_FOO_REGMAP \
+    .base = 0x40000000, \
+    .size = 0x400
+#define WHAL_MYPLATFORM_FOO_DRIVER &whal_MyplatformFoo_Driver
 ```
 
+The board uses these in device struct initializers:
+
+```c
+whal_Foo g_whalFoo = {
+    .regmap = { WHAL_MYPLATFORM_FOO_REGMAP },
+    .driver = WHAL_MYPLATFORM_FOO_DRIVER,
+    .cfg = &fooCfg,
+};
+```
+
+When direct API mapping is active for a device type, the board omits the
+`.driver` field since the vtable is unused.
+
 ---
 
 ## Clock
@@ -462,8 +515,10 @@ transfer. The buffer must remain valid until the transfer completes. The
 driver signals completion through a platform-specific mechanism.
 
 Drivers that do not support async should set SendAsync to NULL in the vtable.
-The dispatch layer returns WHAL_EINVAL when the caller tries to use a NULL
-async function.
+The dispatch layer returns WHAL_ENOTIMPL when the caller tries to use any
+NULL vtable entry (or when the driver pointer itself is NULL). When direct
+API mapping is active, polled drivers provide stub implementations that
+return WHAL_ENOTIMPL directly.
 
 ### RecvAsync
 
@@ -472,7 +527,8 @@ transfer. The buffer must remain valid until the transfer completes.
 
 The async variants are optional — a driver vtable only needs to populate
 them if the platform supports non-blocking transfers. Polled-only drivers
-leave these NULL.
+leave these NULL (the dispatch layer returns WHAL_ENOTIMPL) or provide
+stubs returning WHAL_ENOTIMPL (direct API mapping).
 
 ---
 
diff --git a/src/block/block.c b/src/block/block.c
index 63c7101..8afadd7 100644
--- a/src/block/block.c
+++ b/src/block/block.c
@@ -4,18 +4,20 @@
 
 inline whal_Error whal_Block_Init(whal_Block *blockDev)
 {
-    if (!blockDev || !blockDev->driver || !blockDev->driver->Init) {
+    if (!blockDev)
         return WHAL_EINVAL;
-    }
+    if (!blockDev->driver || !blockDev->driver->Init)
+        return WHAL_ENOTIMPL;
 
     return blockDev->driver->Init(blockDev);
 }
 
 inline whal_Error whal_Block_Deinit(whal_Block *blockDev)
 {
-    if (!blockDev || !blockDev->driver || !blockDev->driver->Deinit) {
+    if (!blockDev)
         return WHAL_EINVAL;
-    }
+    if (!blockDev->driver || !blockDev->driver->Deinit)
+        return WHAL_ENOTIMPL;
 
     return blockDev->driver->Deinit(blockDev);
 }
@@ -23,9 +25,10 @@ inline whal_Error whal_Block_Deinit(whal_Block *blockDev)
 inline whal_Error whal_Block_Read(whal_Block *blockDev, uint32_t block,
                                   void *data, uint32_t blockCount)
 {
-    if (!blockDev || !blockDev->driver || !blockDev->driver->Read || !data) {
+    if (!blockDev || !data)
         return WHAL_EINVAL;
-    }
+    if (!blockDev->driver || !blockDev->driver->Read)
+        return WHAL_ENOTIMPL;
 
     return blockDev->driver->Read(blockDev, block, data, blockCount);
 }
@@ -33,9 +36,10 @@ inline whal_Error whal_Block_Read(whal_Block *blockDev, uint32_t block,
 inline whal_Error whal_Block_Write(whal_Block *blockDev, uint32_t block,
                                    const void *data, uint32_t blockCount)
 {
-    if (!blockDev || !blockDev->driver || !blockDev->driver->Write || !data) {
+    if (!blockDev || !data)
         return WHAL_EINVAL;
-    }
+    if (!blockDev->driver || !blockDev->driver->Write)
+        return WHAL_ENOTIMPL;
 
     return blockDev->driver->Write(blockDev, block, data, blockCount);
 }
@@ -43,9 +47,10 @@ inline whal_Error whal_Block_Write(whal_Block *blockDev, uint32_t block,
 inline whal_Error whal_Block_Erase(whal_Block *blockDev, uint32_t block,
                                    uint32_t blockCount)
 {
-    if (!blockDev || !blockDev->driver || !blockDev->driver->Erase) {
+    if (!blockDev)
         return WHAL_EINVAL;
-    }
+    if (!blockDev->driver || !blockDev->driver->Erase)
+        return WHAL_ENOTIMPL;
 
     return blockDev->driver->Erase(blockDev, block, blockCount);
 }
diff --git a/src/block/sdhc_spi_block.c b/src/block/sdhc_spi_block.c
index 3333b4d..7696232 100644
--- a/src/block/sdhc_spi_block.c
+++ b/src/block/sdhc_spi_block.c
@@ -36,6 +36,14 @@
 
 #define DUMMY 0xFF
 
+#ifdef WHAL_CFG_BLOCK_API_MAPPING_SDHC_SPI
+#define whal_SdhcSpi_Init   whal_Block_Init
+#define whal_SdhcSpi_Deinit whal_Block_Deinit
+#define whal_SdhcSpi_Read   whal_Block_Read
+#define whal_SdhcSpi_Write  whal_Block_Write
+#define whal_SdhcSpi_Erase  whal_Block_Erase
+#endif /* WHAL_CFG_BLOCK_API_MAPPING_SDHC_SPI */
+
 static whal_Error SdhcSpi_CsAssert(whal_SdhcSpi_Cfg *cfg)
 {
     uint8_t dummy = DUMMY;
@@ -479,6 +487,7 @@ whal_Error whal_SdhcSpi_Erase(whal_Block *blockDev, uint32_t block,
     return err;
 }
 
+#ifndef WHAL_CFG_BLOCK_API_MAPPING_SDHC_SPI
 const whal_BlockDriver whal_SdhcSpi_Driver = {
     .Init = whal_SdhcSpi_Init,
     .Deinit = whal_SdhcSpi_Deinit,
@@ -486,3 +495,4 @@ const whal_BlockDriver whal_SdhcSpi_Driver = {
     .Write = whal_SdhcSpi_Write,
     .Erase = whal_SdhcSpi_Erase,
 };
+#endif /* !WHAL_CFG_BLOCK_API_MAPPING_SDHC_SPI */
diff --git a/src/clock/clock.c b/src/clock/clock.c
index cf950f8..c3fba99 100644
--- a/src/clock/clock.c
+++ b/src/clock/clock.c
@@ -3,36 +3,40 @@
 
 inline whal_Error whal_Clock_Init(whal_Clock *clkDev)
 {
-    if (!clkDev || !clkDev->driver || !clkDev->driver->Init) {
+    if (!clkDev)
         return WHAL_EINVAL;
-    }
+    if (!clkDev->driver || !clkDev->driver->Init)
+        return WHAL_ENOTIMPL;
 
     return clkDev->driver->Init(clkDev);
 }
 
 inline whal_Error whal_Clock_Deinit(whal_Clock *clkDev)
 {
-    if (!clkDev || !clkDev->driver || !clkDev->driver->Deinit) {
+    if (!clkDev)
         return WHAL_EINVAL;
-    }
+    if (!clkDev->driver || !clkDev->driver->Deinit)
+        return WHAL_ENOTIMPL;
 
     return clkDev->driver->Deinit(clkDev);
 }
 
 inline whal_Error whal_Clock_Enable(whal_Clock *clkDev, const void *clk)
 {
-    if (!clkDev || !clkDev->driver || !clkDev->driver->Enable) {
+    if (!clkDev)
         return WHAL_EINVAL;
-    }
+    if (!clkDev->driver || !clkDev->driver->Enable)
+        return WHAL_ENOTIMPL;
 
     return clkDev->driver->Enable(clkDev, clk);
 }
 
 inline whal_Error whal_Clock_Disable(whal_Clock *clkDev, const void *clk)
 {
-    if (!clkDev || !clkDev->driver || !clkDev->driver->Disable) {
+    if (!clkDev)
         return WHAL_EINVAL;
-    }
+    if (!clkDev->driver || !clkDev->driver->Disable)
+        return WHAL_ENOTIMPL;
 
     return clkDev->driver->Disable(clkDev, clk);
 }
diff --git a/src/clock/pic32cz_clock.c b/src/clock/pic32cz_clock.c
index c0c75c1..5a4852b 100644
--- a/src/clock/pic32cz_clock.c
+++ b/src/clock/pic32cz_clock.c
@@ -92,6 +92,13 @@
 /* Peripheral Clock Mask Registers - enable/disable bus clocks to peripherals */
 #define MCLK_CLKxMSK_REG(enableInst) (MCLK + 0x3C + (enableInst * 0x4))
 
+#ifdef WHAL_CFG_CLOCK_API_MAPPING_PIC32CZ_PLL
+#define whal_Pic32czClockPll_Init   whal_Clock_Init
+#define whal_Pic32czClockPll_Deinit whal_Clock_Deinit
+#define whal_Pic32czClock_Enable    whal_Clock_Enable
+#define whal_Pic32czClock_Disable   whal_Clock_Disable
+#endif /* WHAL_CFG_CLOCK_API_MAPPING_PIC32CZ_PLL */
+
 whal_Error whal_Pic32czClockPll_Init(whal_Clock *clkDev)
 {
     whal_Pic32czClock_Cfg *cfg;
@@ -238,9 +245,11 @@ whal_Error whal_Pic32czClock_Disable(whal_Clock *clkDev, const void *clk)
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_CLOCK_API_MAPPING_PIC32CZ_PLL
 const whal_ClockDriver whal_Pic32czClockPll_Driver = {
     .Init = whal_Pic32czClockPll_Init,
     .Deinit = whal_Pic32czClockPll_Deinit,
     .Enable = whal_Pic32czClock_Enable,
     .Disable = whal_Pic32czClock_Disable,
 };
+#endif /* !WHAL_CFG_CLOCK_API_MAPPING_PIC32CZ_PLL */
diff --git a/src/clock/stm32c0_rcc.c b/src/clock/stm32c0_rcc.c
index 9dd3836..e1831b2 100644
--- a/src/clock/stm32c0_rcc.c
+++ b/src/clock/stm32c0_rcc.c
@@ -35,6 +35,13 @@
 /* HSISYS clock source selection value */
 #define RCC_CFGR_SW_HSISYS 0
 
+#ifdef WHAL_CFG_CLOCK_API_MAPPING_STM32C0
+#define whal_Stm32c0Rcc_Init    whal_Clock_Init
+#define whal_Stm32c0Rcc_Deinit  whal_Clock_Deinit
+#define whal_Stm32c0Rcc_Enable  whal_Clock_Enable
+#define whal_Stm32c0Rcc_Disable whal_Clock_Disable
+#endif /* WHAL_CFG_CLOCK_API_MAPPING_STM32C0 */
+
 whal_Error whal_Stm32c0Rcc_Init(whal_Clock *clkDev)
 {
     whal_Stm32c0Rcc_Cfg *cfg;
@@ -114,9 +121,11 @@ whal_Error whal_Stm32c0Rcc_Disable(whal_Clock *clkDev, const void *clk)
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_CLOCK_API_MAPPING_STM32C0
 const whal_ClockDriver whal_Stm32c0Rcc_Driver = {
     .Init = whal_Stm32c0Rcc_Init,
     .Deinit = whal_Stm32c0Rcc_Deinit,
     .Enable = whal_Stm32c0Rcc_Enable,
     .Disable = whal_Stm32c0Rcc_Disable,
 };
+#endif /* !WHAL_CFG_CLOCK_API_MAPPING_STM32C0 */
diff --git a/src/clock/stm32f4_rcc.c b/src/clock/stm32f4_rcc.c
index 3972c5e..b71c694 100644
--- a/src/clock/stm32f4_rcc.c
+++ b/src/clock/stm32f4_rcc.c
@@ -72,6 +72,13 @@
 #define RCC_CFGR_PPRE2_Pos 13
 #define RCC_CFGR_PPRE2_Msk (WHAL_BITMASK(3) << RCC_CFGR_PPRE2_Pos)
 
+#ifdef WHAL_CFG_CLOCK_API_MAPPING_STM32F4_PLL
+#define whal_Stm32f4RccPll_Init   whal_Clock_Init
+#define whal_Stm32f4RccPll_Deinit whal_Clock_Deinit
+#define whal_Stm32f4Rcc_Enable    whal_Clock_Enable
+#define whal_Stm32f4Rcc_Disable   whal_Clock_Disable
+#endif /* WHAL_CFG_CLOCK_API_MAPPING_STM32F4_PLL */
+
 whal_Error whal_Stm32f4RccPll_Init(whal_Clock *clkDev)
 {
     whal_Stm32f4Rcc_Cfg *cfg;
@@ -208,9 +215,11 @@ whal_Error whal_Stm32f4Rcc_Disable(whal_Clock *clkDev, const void *clk)
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_CLOCK_API_MAPPING_STM32F4_PLL
 const whal_ClockDriver whal_Stm32f4RccPll_Driver = {
     .Init = whal_Stm32f4RccPll_Init,
     .Deinit = whal_Stm32f4RccPll_Deinit,
     .Enable = whal_Stm32f4Rcc_Enable,
     .Disable = whal_Stm32f4Rcc_Disable,
 };
+#endif /* !WHAL_CFG_CLOCK_API_MAPPING_STM32F4_PLL */
diff --git a/src/clock/stm32h5_rcc.c b/src/clock/stm32h5_rcc.c
index f71ef10..54e5875 100644
--- a/src/clock/stm32h5_rcc.c
+++ b/src/clock/stm32h5_rcc.c
@@ -102,6 +102,22 @@
 /* HSI base frequency */
 #define HSI_FREQ 64000000UL
 
+#if defined(WHAL_CFG_CLOCK_API_MAPPING_STM32H5_PLL) || \
+    defined(WHAL_CFG_CLOCK_API_MAPPING_STM32H5_HSI)
+#define whal_Stm32h5Rcc_Enable  whal_Clock_Enable
+#define whal_Stm32h5Rcc_Disable whal_Clock_Disable
+#endif
+
+#ifdef WHAL_CFG_CLOCK_API_MAPPING_STM32H5_PLL
+#define whal_Stm32h5RccPll_Init   whal_Clock_Init
+#define whal_Stm32h5RccPll_Deinit whal_Clock_Deinit
+#endif /* WHAL_CFG_CLOCK_API_MAPPING_STM32H5_PLL */
+
+#ifdef WHAL_CFG_CLOCK_API_MAPPING_STM32H5_HSI
+#define whal_Stm32h5RccHsi_Init   whal_Clock_Init
+#define whal_Stm32h5RccHsi_Deinit whal_Clock_Deinit
+#endif /* WHAL_CFG_CLOCK_API_MAPPING_STM32H5_HSI */
+
 whal_Error whal_Stm32h5RccPll_Init(whal_Clock *clkDev)
 {
     whal_Stm32h5Rcc_Cfg *cfg;
@@ -310,6 +326,7 @@ whal_Error whal_Stm32h5Rcc_Disable(whal_Clock *clkDev, const void *clk)
     return WHAL_SUCCESS;
 }
 
+#if !defined(WHAL_CFG_CLOCK_API_MAPPING_STM32H5_PLL) && !defined(WHAL_CFG_CLOCK_API_MAPPING_STM32H5_HSI)
 const whal_ClockDriver whal_Stm32h5RccPll_Driver = {
     .Init = whal_Stm32h5RccPll_Init,
     .Deinit = whal_Stm32h5RccPll_Deinit,
@@ -323,6 +340,7 @@ const whal_ClockDriver whal_Stm32h5RccHsi_Driver = {
     .Enable = whal_Stm32h5Rcc_Enable,
     .Disable = whal_Stm32h5Rcc_Disable,
 };
+#endif /* !WHAL_CFG_CLOCK_API_MAPPING_STM32H5_PLL && !WHAL_CFG_CLOCK_API_MAPPING_STM32H5_HSI */
 
 whal_Error whal_Stm32h5Rcc_Ext_EnableHsi48(whal_Clock *clkDev, uint8_t enable)
 {
diff --git a/src/clock/stm32wb_rcc.c b/src/clock/stm32wb_rcc.c
index c8e7554..636c690 100644
--- a/src/clock/stm32wb_rcc.c
+++ b/src/clock/stm32wb_rcc.c
@@ -147,6 +147,22 @@
 #define RCC_CRRCR_HSI48RDY_Pos 1                                                  /* HSI48 oscillator ready */
 #define RCC_CRRCR_HSI48RDY_Msk (1UL << RCC_CRRCR_HSI48RDY_Pos)
 
+#if defined(WHAL_CFG_CLOCK_API_MAPPING_STM32WB_PLL) || \
+    defined(WHAL_CFG_CLOCK_API_MAPPING_STM32WB_MSI)
+#define whal_Stm32wbRcc_Enable  whal_Clock_Enable
+#define whal_Stm32wbRcc_Disable whal_Clock_Disable
+#endif
+
+#ifdef WHAL_CFG_CLOCK_API_MAPPING_STM32WB_PLL
+#define whal_Stm32wbRccPll_Init   whal_Clock_Init
+#define whal_Stm32wbRccPll_Deinit whal_Clock_Deinit
+#endif /* WHAL_CFG_CLOCK_API_MAPPING_STM32WB_PLL */
+
+#ifdef WHAL_CFG_CLOCK_API_MAPPING_STM32WB_MSI
+#define whal_Stm32wbRccMsi_Init   whal_Clock_Init
+#define whal_Stm32wbRccMsi_Deinit whal_Clock_Deinit
+#endif /* WHAL_CFG_CLOCK_API_MAPPING_STM32WB_MSI */
+
 whal_Error whal_Stm32wbRccPll_Init(whal_Clock *clkDev)
 {
     whal_Stm32wbRcc_Cfg *cfg;
@@ -302,6 +318,7 @@ whal_Error whal_Stm32wbRcc_Ext_EnableLsi(whal_Clock *clkDev, uint8_t enable)
     return WHAL_SUCCESS;
 }
 
+#if !defined(WHAL_CFG_CLOCK_API_MAPPING_STM32WB_PLL) && !defined(WHAL_CFG_CLOCK_API_MAPPING_STM32WB_MSI)
 const whal_ClockDriver whal_Stm32wbRccPll_Driver = {
     .Init = whal_Stm32wbRccPll_Init,
     .Deinit = whal_Stm32wbRccPll_Deinit,
@@ -315,3 +332,4 @@ const whal_ClockDriver whal_Stm32wbRccMsi_Driver = {
     .Enable = whal_Stm32wbRcc_Enable,
     .Disable = whal_Stm32wbRcc_Disable,
 };
+#endif /* !WHAL_CFG_CLOCK_API_MAPPING_STM32WB_PLL && !WHAL_CFG_CLOCK_API_MAPPING_STM32WB_MSI */
diff --git a/src/crypto/crypto.c b/src/crypto/crypto.c
index 81925b0..a60ddb0 100644
--- a/src/crypto/crypto.c
+++ b/src/crypto/crypto.c
@@ -1,6 +1,7 @@
 #include <wolfHAL/crypto/crypto.h>
 #include <wolfHAL/error.h>
 
+#ifndef WHAL_CFG_CRYPTO_API_MAPPING_STM32WB_AES
 whal_Error whal_Crypto_Init(whal_Crypto *cryptoDev)
 {
     if (!cryptoDev || !cryptoDev->driver || !cryptoDev->driver->Init) {
@@ -18,6 +19,7 @@ whal_Error whal_Crypto_Deinit(whal_Crypto *cryptoDev)
 
     return cryptoDev->driver->Deinit(cryptoDev);
 }
+#endif
 
 whal_Error whal_Crypto_Op(whal_Crypto *cryptoDev, size_t op, void *opArgs)
 {
diff --git a/src/crypto/stm32wb_aes.c b/src/crypto/stm32wb_aes.c
index 349cde9..0151ae6 100644
--- a/src/crypto/stm32wb_aes.c
+++ b/src/crypto/stm32wb_aes.c
@@ -149,6 +149,11 @@ static whal_Error WaitForCCF(size_t base, whal_Timeout *timeout)
 }
 
 
+#ifdef WHAL_CFG_CRYPTO_API_MAPPING_STM32WB_AES
+#define whal_Stm32wbAes_Init   whal_Crypto_Init
+#define whal_Stm32wbAes_Deinit whal_Crypto_Deinit
+#endif /* WHAL_CFG_CRYPTO_API_MAPPING_STM32WB_AES */
+
 whal_Error whal_Stm32wbAes_Init(whal_Crypto *cryptoDev)
 {
     if (!cryptoDev || !cryptoDev->cfg) {
@@ -922,7 +927,9 @@ whal_Error whal_Stm32wbAes_AesCcm(whal_Crypto *cryptoDev, void *opArgs)
     return err;
 }
 
+#ifndef WHAL_CFG_CRYPTO_API_MAPPING_STM32WB_AES
 const whal_CryptoDriver whal_Stm32wbAes_Driver = {
     .Init = whal_Stm32wbAes_Init,
     .Deinit = whal_Stm32wbAes_Deinit,
 };
+#endif /* !WHAL_CFG_CRYPTO_API_MAPPING_STM32WB_AES */
diff --git a/src/dma/stm32wb_dma.c b/src/dma/stm32wb_dma.c
index 8f43609..d7fbb48 100644
--- a/src/dma/stm32wb_dma.c
+++ b/src/dma/stm32wb_dma.c
@@ -88,7 +88,15 @@
 #define DMAMUX_CxCR_DMAREQ_ID_Pos  0
 #define DMAMUX_CxCR_DMAREQ_ID_Msk  (WHAL_BITMASK(6) << DMAMUX_CxCR_DMAREQ_ID_Pos)
 
-static whal_Error whal_Stm32wbDma_Init(whal_Dma *dmaDev)
+#ifdef WHAL_CFG_DMA_API_MAPPING_STM32WB
+#define whal_Stm32wbDma_Init      whal_Dma_Init
+#define whal_Stm32wbDma_Deinit    whal_Dma_Deinit
+#define whal_Stm32wbDma_Configure whal_Dma_Configure
+#define whal_Stm32wbDma_Start     whal_Dma_Start
+#define whal_Stm32wbDma_Stop      whal_Dma_Stop
+#endif /* WHAL_CFG_DMA_API_MAPPING_STM32WB */
+
+whal_Error whal_Stm32wbDma_Init(whal_Dma *dmaDev)
 {
     whal_Stm32wbDma_Cfg *cfg;
     size_t base;
@@ -112,7 +120,7 @@ static whal_Error whal_Stm32wbDma_Init(whal_Dma *dmaDev)
     return WHAL_SUCCESS;
 }
 
-static whal_Error whal_Stm32wbDma_Deinit(whal_Dma *dmaDev)
+whal_Error whal_Stm32wbDma_Deinit(whal_Dma *dmaDev)
 {
     whal_Stm32wbDma_Cfg *cfg;
     size_t base;
@@ -142,7 +150,7 @@ static whal_Error whal_Stm32wbDma_Deinit(whal_Dma *dmaDev)
     return WHAL_SUCCESS;
 }
 
-static whal_Error whal_Stm32wbDma_Configure(whal_Dma *dmaDev, size_t ch,
+whal_Error whal_Stm32wbDma_Configure(whal_Dma *dmaDev, size_t ch,
                                              const void *chCfg)
 {
     whal_Stm32wbDma_Cfg *cfg;
@@ -262,7 +270,7 @@ static whal_Error whal_Stm32wbDma_Configure(whal_Dma *dmaDev, size_t ch,
     return WHAL_SUCCESS;
 }
 
-static whal_Error whal_Stm32wbDma_Start(whal_Dma *dmaDev, size_t ch)
+whal_Error whal_Stm32wbDma_Start(whal_Dma *dmaDev, size_t ch)
 {
     whal_Stm32wbDma_Cfg *cfg;
     size_t base;
@@ -292,7 +300,7 @@ static whal_Error whal_Stm32wbDma_Start(whal_Dma *dmaDev, size_t ch)
     return WHAL_SUCCESS;
 }
 
-static whal_Error whal_Stm32wbDma_Stop(whal_Dma *dmaDev, size_t ch)
+whal_Error whal_Stm32wbDma_Stop(whal_Dma *dmaDev, size_t ch)
 {
     whal_Stm32wbDma_Cfg *cfg;
     size_t base;
@@ -347,6 +355,7 @@ void whal_Stm32wbDma_IRQHandler(whal_Dma *dmaDev, size_t ch,
     }
 }
 
+#ifndef WHAL_CFG_DMA_API_MAPPING_STM32WB
 const whal_DmaDriver whal_Stm32wbDma_Driver = {
     .Init = whal_Stm32wbDma_Init,
     .Deinit = whal_Stm32wbDma_Deinit,
@@ -354,3 +363,4 @@ const whal_DmaDriver whal_Stm32wbDma_Driver = {
     .Start = whal_Stm32wbDma_Start,
     .Stop = whal_Stm32wbDma_Stop,
 };
+#endif /* !WHAL_CFG_DMA_API_MAPPING_STM32WB */
diff --git a/src/eth/stm32h5_eth.c b/src/eth/stm32h5_eth.c
index a05d7e4..8c78ce4 100644
--- a/src/eth/stm32h5_eth.c
+++ b/src/eth/stm32h5_eth.c
@@ -123,6 +123,17 @@
 /* MDIO clock range for 168 MHz AHB: CR=4 gives /102 ≈ 1.6 MHz */
 #define ETH_MDIO_CR 4
 
+#ifdef WHAL_CFG_ETH_API_MAPPING_STM32H5
+#define whal_Stm32h5Eth_Init      whal_Eth_Init
+#define whal_Stm32h5Eth_Deinit    whal_Eth_Deinit
+#define whal_Stm32h5Eth_Start     whal_Eth_Start
+#define whal_Stm32h5Eth_Stop      whal_Eth_Stop
+#define whal_Stm32h5Eth_Send      whal_Eth_Send
+#define whal_Stm32h5Eth_Recv      whal_Eth_Recv
+#define whal_Stm32h5Eth_MdioRead  whal_Eth_MdioRead
+#define whal_Stm32h5Eth_MdioWrite whal_Eth_MdioWrite
+#endif /* WHAL_CFG_ETH_API_MAPPING_STM32H5 */
+
 static whal_Error MdioPoll(size_t base, whal_Timeout *timeout)
 {
     return whal_Reg_ReadPoll(base, ETH_MACMDIOAR_REG,
@@ -490,6 +501,7 @@ whal_Error whal_Stm32h5Eth_Ext_EnableLoopback(whal_Eth *ethDev,
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_ETH_API_MAPPING_STM32H5
 const whal_EthDriver whal_Stm32h5Eth_Driver = {
     .Init = whal_Stm32h5Eth_Init,
     .Deinit = whal_Stm32h5Eth_Deinit,
@@ -500,3 +512,4 @@ const whal_EthDriver whal_Stm32h5Eth_Driver = {
     .MdioRead = whal_Stm32h5Eth_MdioRead,
     .MdioWrite = whal_Stm32h5Eth_MdioWrite,
 };
+#endif /* !WHAL_CFG_ETH_API_MAPPING_STM32H5 */
diff --git a/src/eth_phy/lan8742a_eth_phy.c b/src/eth_phy/lan8742a_eth_phy.c
index 530b691..3befcf5 100644
--- a/src/eth_phy/lan8742a_eth_phy.c
+++ b/src/eth_phy/lan8742a_eth_phy.c
@@ -21,6 +21,12 @@
 #define PHY_PHYSCSR_100HD  (2UL << 2)
 #define PHY_PHYSCSR_100FD  (6UL << 2)
 
+#ifdef WHAL_CFG_ETH_PHY_API_MAPPING_LAN8742A
+#define whal_Lan8742a_Init         whal_EthPhy_Init
+#define whal_Lan8742a_Deinit       whal_EthPhy_Deinit
+#define whal_Lan8742a_GetLinkState whal_EthPhy_GetLinkState
+#endif /* WHAL_CFG_ETH_PHY_API_MAPPING_LAN8742A */
+
 whal_Error whal_Lan8742a_Init(whal_EthPhy *phyDev)
 {
     whal_Lan8742a_Cfg *cfg;
@@ -121,8 +127,10 @@ whal_Error whal_Lan8742a_GetLinkState(whal_EthPhy *phyDev, uint8_t *up,
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_ETH_PHY_API_MAPPING_LAN8742A
 const whal_EthPhyDriver whal_Lan8742a_Driver = {
     .Init = whal_Lan8742a_Init,
     .Deinit = whal_Lan8742a_Deinit,
     .GetLinkState = whal_Lan8742a_GetLinkState,
 };
+#endif /* !WHAL_CFG_ETH_PHY_API_MAPPING_LAN8742A */
diff --git a/src/flash/flash.c b/src/flash/flash.c
index e6a5899..28b2ca5 100644
--- a/src/flash/flash.c
+++ b/src/flash/flash.c
@@ -4,36 +4,40 @@
 
 inline whal_Error whal_Flash_Init(whal_Flash *flashDev)
 {
-    if (!flashDev || !flashDev->driver || !flashDev->driver->Init) {
+    if (!flashDev)
         return WHAL_EINVAL;
-    }
+    if (!flashDev->driver || !flashDev->driver->Init)
+        return WHAL_ENOTIMPL;
 
     return flashDev->driver->Init(flashDev);
 }
 
 inline whal_Error whal_Flash_Deinit(whal_Flash *flashDev)
 {
-    if (!flashDev || !flashDev->driver || !flashDev->driver->Deinit) {
+    if (!flashDev)
         return WHAL_EINVAL;
-    }
+    if (!flashDev->driver || !flashDev->driver->Deinit)
+        return WHAL_ENOTIMPL;
 
     return flashDev->driver->Deinit(flashDev);
 }
 
 inline whal_Error whal_Flash_Lock(whal_Flash *flashDev, size_t addr, size_t len)
 {
-    if (!flashDev || !flashDev->driver || !flashDev->driver->Lock) {
+    if (!flashDev)
         return WHAL_EINVAL;
-    }
+    if (!flashDev->driver || !flashDev->driver->Lock)
+        return WHAL_ENOTIMPL;
 
     return flashDev->driver->Lock(flashDev, addr, len);
 }
 
 inline whal_Error whal_Flash_Unlock(whal_Flash *flashDev, size_t addr, size_t len)
 {
-    if (!flashDev || !flashDev->driver || !flashDev->driver->Unlock) {
+    if (!flashDev)
         return WHAL_EINVAL;
-    }
+    if (!flashDev->driver || !flashDev->driver->Unlock)
+        return WHAL_ENOTIMPL;
 
     return flashDev->driver->Unlock(flashDev, addr, len);
 }
@@ -41,9 +45,10 @@ inline whal_Error whal_Flash_Unlock(whal_Flash *flashDev, size_t addr, size_t le
 inline whal_Error whal_Flash_Read(whal_Flash *flashDev, size_t addr, void *data,
                                   size_t dataSz)
 {
-    if (!flashDev || !flashDev->driver || !flashDev->driver->Read || !data) {
+    if (!flashDev || !data)
         return WHAL_EINVAL;
-    }
+    if (!flashDev->driver || !flashDev->driver->Read)
+        return WHAL_ENOTIMPL;
 
     return flashDev->driver->Read(flashDev, addr, data, dataSz);
 }
@@ -51,9 +56,10 @@ inline whal_Error whal_Flash_Read(whal_Flash *flashDev, size_t addr, void *data,
 inline whal_Error whal_Flash_Write(whal_Flash *flashDev, size_t addr, const void *data,
                                   size_t dataSz)
 {
-    if (!flashDev || !flashDev->driver || !flashDev->driver->Write || !data) {
+    if (!flashDev || !data)
         return WHAL_EINVAL;
-    }
+    if (!flashDev->driver || !flashDev->driver->Write)
+        return WHAL_ENOTIMPL;
 
     return flashDev->driver->Write(flashDev, addr, data, dataSz);
 }
@@ -61,9 +67,10 @@ inline whal_Error whal_Flash_Write(whal_Flash *flashDev, size_t addr, const void
 inline whal_Error whal_Flash_Erase(whal_Flash *flashDev, size_t addr,
                                   size_t dataSz)
 {
-    if (!flashDev || !flashDev->driver || !flashDev->driver->Erase) {
+    if (!flashDev)
         return WHAL_EINVAL;
-    }
+    if (!flashDev->driver || !flashDev->driver->Erase)
+        return WHAL_ENOTIMPL;
 
     return flashDev->driver->Erase(flashDev, addr, dataSz);
 }
diff --git a/src/flash/pic32cz_flash.c b/src/flash/pic32cz_flash.c
index 4ba946b..c9f1e58 100644
--- a/src/flash/pic32cz_flash.c
+++ b/src/flash/pic32cz_flash.c
@@ -94,6 +94,16 @@
 #define FCW_DWORD_SIZE          8
 #define FCW_QDWORD_SIZE         32
 
+#ifdef WHAL_CFG_FLASH_API_MAPPING_PIC32CZ
+#define whal_Pic32czFlash_Init   whal_Flash_Init
+#define whal_Pic32czFlash_Deinit whal_Flash_Deinit
+#define whal_Pic32czFlash_Lock   whal_Flash_Lock
+#define whal_Pic32czFlash_Unlock whal_Flash_Unlock
+#define whal_Pic32czFlash_Read   whal_Flash_Read
+#define whal_Pic32czFlash_Write  whal_Flash_Write
+#define whal_Pic32czFlash_Erase  whal_Flash_Erase
+#endif /* WHAL_CFG_FLASH_API_MAPPING_PIC32CZ */
+
 static whal_Error whal_Pic32czFlash_MutexLock(const whal_Regmap *reg,
                                               whal_Timeout *timeout)
 {
@@ -403,6 +413,7 @@ whal_Error whal_Pic32czFlash_Erase(whal_Flash *flashDev, size_t addr, size_t dat
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_FLASH_API_MAPPING_PIC32CZ
 const whal_FlashDriver whal_Pic32czFlash_Driver = {
     .Init = whal_Pic32czFlash_Init,
     .Deinit = whal_Pic32czFlash_Deinit,
@@ -412,3 +423,4 @@ const whal_FlashDriver whal_Pic32czFlash_Driver = {
     .Write = whal_Pic32czFlash_Write,
     .Erase = whal_Pic32czFlash_Erase,
 };
+#endif /* !WHAL_CFG_FLASH_API_MAPPING_PIC32CZ */
diff --git a/src/flash/spi_nor_flash.c b/src/flash/spi_nor_flash.c
index df5d7a7..bfe50c5 100644
--- a/src/flash/spi_nor_flash.c
+++ b/src/flash/spi_nor_flash.c
@@ -48,6 +48,7 @@
 
 #define DUMMY 0xFF
 
+
 static whal_Error SpiNor_CsAssert(whal_SpiNor_Cfg *cfg)
 {
     return whal_Gpio_Set(cfg->gpioDev, cfg->csPin, 0);
diff --git a/src/flash/stm32c0_flash.c b/src/flash/stm32c0_flash.c
index dc4cf2e..c3e8276 100644
--- a/src/flash/stm32c0_flash.c
+++ b/src/flash/stm32c0_flash.c
@@ -85,6 +85,16 @@
 #define FLASH_CR_LOCK_Pos 31         /* Lock flash control */
 #define FLASH_CR_LOCK_Msk (1UL << FLASH_CR_LOCK_Pos)
 
+#ifdef WHAL_CFG_FLASH_API_MAPPING_STM32C0
+#define whal_Stm32c0Flash_Init   whal_Flash_Init
+#define whal_Stm32c0Flash_Deinit whal_Flash_Deinit
+#define whal_Stm32c0Flash_Lock   whal_Flash_Lock
+#define whal_Stm32c0Flash_Unlock whal_Flash_Unlock
+#define whal_Stm32c0Flash_Read   whal_Flash_Read
+#define whal_Stm32c0Flash_Write  whal_Flash_Write
+#define whal_Stm32c0Flash_Erase  whal_Flash_Erase
+#endif /* WHAL_CFG_FLASH_API_MAPPING_STM32C0 */
+
 whal_Error whal_Stm32c0Flash_Init(whal_Flash *flashDev)
 {
     (void)flashDev;
@@ -292,6 +302,7 @@ whal_Error whal_Stm32c0Flash_Ext_SetLatency(whal_Flash *flashDev, enum whal_Stm3
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_FLASH_API_MAPPING_STM32C0
 const whal_FlashDriver whal_Stm32c0Flash_Driver = {
     .Init = whal_Stm32c0Flash_Init,
     .Deinit = whal_Stm32c0Flash_Deinit,
@@ -301,3 +312,4 @@ const whal_FlashDriver whal_Stm32c0Flash_Driver = {
     .Write = whal_Stm32c0Flash_Write,
     .Erase = whal_Stm32c0Flash_Erase,
 };
+#endif /* !WHAL_CFG_FLASH_API_MAPPING_STM32C0 */
diff --git a/src/flash/stm32f4_flash.c b/src/flash/stm32f4_flash.c
index 7ffb7a0..b94673c 100644
--- a/src/flash/stm32f4_flash.c
+++ b/src/flash/stm32f4_flash.c
@@ -79,6 +79,16 @@
 #define FLASH_KEY1 0x45670123UL
 #define FLASH_KEY2 0xCDEF89ABUL
 
+#ifdef WHAL_CFG_FLASH_API_MAPPING_STM32F4
+#define whal_Stm32f4Flash_Init   whal_Flash_Init
+#define whal_Stm32f4Flash_Deinit whal_Flash_Deinit
+#define whal_Stm32f4Flash_Lock   whal_Flash_Lock
+#define whal_Stm32f4Flash_Unlock whal_Flash_Unlock
+#define whal_Stm32f4Flash_Read   whal_Flash_Read
+#define whal_Stm32f4Flash_Write  whal_Flash_Write
+#define whal_Stm32f4Flash_Erase  whal_Flash_Erase
+#endif /* WHAL_CFG_FLASH_API_MAPPING_STM32F4 */
+
 whal_Error whal_Stm32f4Flash_Init(whal_Flash *flashDev)
 {
     (void)flashDev;
@@ -293,6 +303,7 @@ whal_Error whal_Stm32f4Flash_Ext_SetLatency(whal_Flash *flashDev,
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_FLASH_API_MAPPING_STM32F4
 const whal_FlashDriver whal_Stm32f4Flash_Driver = {
     .Init = whal_Stm32f4Flash_Init,
     .Deinit = whal_Stm32f4Flash_Deinit,
@@ -302,3 +313,4 @@ const whal_FlashDriver whal_Stm32f4Flash_Driver = {
     .Write = whal_Stm32f4Flash_Write,
     .Erase = whal_Stm32f4Flash_Erase,
 };
+#endif /* !WHAL_CFG_FLASH_API_MAPPING_STM32F4 */
diff --git a/src/flash/stm32h5_flash.c b/src/flash/stm32h5_flash.c
index 674b6be..2e95fa5 100644
--- a/src/flash/stm32h5_flash.c
+++ b/src/flash/stm32h5_flash.c
@@ -108,6 +108,16 @@
 /* Bank size: 1 MB */
 #define FLASH_BANK_SIZE (FLASH_SECTORS_PER_BANK * FLASH_SECTOR_SIZE)
 
+#ifdef WHAL_CFG_FLASH_API_MAPPING_STM32H5
+#define whal_Stm32h5Flash_Init   whal_Flash_Init
+#define whal_Stm32h5Flash_Deinit whal_Flash_Deinit
+#define whal_Stm32h5Flash_Lock   whal_Flash_Lock
+#define whal_Stm32h5Flash_Unlock whal_Flash_Unlock
+#define whal_Stm32h5Flash_Read   whal_Flash_Read
+#define whal_Stm32h5Flash_Write  whal_Flash_Write
+#define whal_Stm32h5Flash_Erase  whal_Flash_Erase
+#endif /* WHAL_CFG_FLASH_API_MAPPING_STM32H5 */
+
 whal_Error whal_Stm32h5Flash_Init(whal_Flash *flashDev)
 {
     (void)flashDev;
@@ -333,6 +343,7 @@ whal_Error whal_Stm32h5Flash_Ext_SetLatency(whal_Flash *flashDev,
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_FLASH_API_MAPPING_STM32H5
 const whal_FlashDriver whal_Stm32h5Flash_Driver = {
     .Init = whal_Stm32h5Flash_Init,
     .Deinit = whal_Stm32h5Flash_Deinit,
@@ -342,3 +353,4 @@ const whal_FlashDriver whal_Stm32h5Flash_Driver = {
     .Write = whal_Stm32h5Flash_Write,
     .Erase = whal_Stm32h5Flash_Erase,
 };
+#endif /* !WHAL_CFG_FLASH_API_MAPPING_STM32H5 */
diff --git a/src/flash/stm32wb_flash.c b/src/flash/stm32wb_flash.c
index 50747cd..0c16c45 100644
--- a/src/flash/stm32wb_flash.c
+++ b/src/flash/stm32wb_flash.c
@@ -88,6 +88,16 @@
 #define FLASH_CR_LOCK_Pos 31         /* Lock flash control */
 #define FLASH_CR_LOCK_Msk (1UL << FLASH_CR_LOCK_Pos)
 
+#ifdef WHAL_CFG_FLASH_API_MAPPING_STM32WB
+#define whal_Stm32wbFlash_Init   whal_Flash_Init
+#define whal_Stm32wbFlash_Deinit whal_Flash_Deinit
+#define whal_Stm32wbFlash_Lock   whal_Flash_Lock
+#define whal_Stm32wbFlash_Unlock whal_Flash_Unlock
+#define whal_Stm32wbFlash_Read   whal_Flash_Read
+#define whal_Stm32wbFlash_Write  whal_Flash_Write
+#define whal_Stm32wbFlash_Erase  whal_Flash_Erase
+#endif /* WHAL_CFG_FLASH_API_MAPPING_STM32WB */
+
 whal_Error whal_Stm32wbFlash_Init(whal_Flash *flashDev)
 {
     (void)flashDev;
@@ -294,6 +304,7 @@ whal_Error whal_Stm32wbFlash_Ext_SetLatency(whal_Flash *flashDev, enum whal_Stm3
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_FLASH_API_MAPPING_STM32WB
 const whal_FlashDriver whal_Stm32wbFlash_Driver = {
     .Init = whal_Stm32wbFlash_Init,
     .Deinit = whal_Stm32wbFlash_Deinit,
@@ -303,3 +314,4 @@ const whal_FlashDriver whal_Stm32wbFlash_Driver = {
     .Write = whal_Stm32wbFlash_Write,
     .Erase = whal_Stm32wbFlash_Erase,
 };
+#endif /* !WHAL_CFG_FLASH_API_MAPPING_STM32WB */
diff --git a/src/gpio/gpio.c b/src/gpio/gpio.c
index e4fb23d..2107be9 100644
--- a/src/gpio/gpio.c
+++ b/src/gpio/gpio.c
@@ -3,38 +3,40 @@
 
 inline whal_Error whal_Gpio_Init(whal_Gpio *gpioDev)
 {
-    if (!gpioDev || !gpioDev->driver || !gpioDev->driver->Init) {
+    if (!gpioDev)
         return WHAL_EINVAL;
-    }
+    if (!gpioDev->driver || !gpioDev->driver->Init)
+        return WHAL_ENOTIMPL;
 
     return gpioDev->driver->Init(gpioDev);
 }
 
 inline whal_Error whal_Gpio_Deinit(whal_Gpio *gpioDev)
 {
-    if (!gpioDev || !gpioDev->driver || !gpioDev->driver->Deinit) {
+    if (!gpioDev)
         return WHAL_EINVAL;
-    }
+    if (!gpioDev->driver || !gpioDev->driver->Deinit)
+        return WHAL_ENOTIMPL;
 
     return gpioDev->driver->Deinit(gpioDev);
-    
 }
 
 inline whal_Error whal_Gpio_Get(whal_Gpio *gpioDev, size_t pin, size_t *value)
 {
-    if (!gpioDev || !gpioDev->driver || !gpioDev->driver->Get || !value) {
+    if (!gpioDev || !value)
         return WHAL_EINVAL;
-    }
+    if (!gpioDev->driver || !gpioDev->driver->Get)
+        return WHAL_ENOTIMPL;
 
     return gpioDev->driver->Get(gpioDev, pin, value);
-
 }
 
 inline whal_Error whal_Gpio_Set(whal_Gpio *gpioDev, size_t pin, size_t value)
 {
-    if (!gpioDev || !gpioDev->driver || !gpioDev->driver->Set) {
+    if (!gpioDev)
         return WHAL_EINVAL;
-    }
+    if (!gpioDev->driver || !gpioDev->driver->Set)
+        return WHAL_ENOTIMPL;
 
     return gpioDev->driver->Set(gpioDev, pin, value);
 }
diff --git a/src/gpio/pic32cz_gpio.c b/src/gpio/pic32cz_gpio.c
index 3b61cb9..14b39a7 100644
--- a/src/gpio/pic32cz_gpio.c
+++ b/src/gpio/pic32cz_gpio.c
@@ -51,6 +51,13 @@
 #define PINCFGx_PULLEN_Pos(pin) (2 + (((pin) & 3) * 8))
 #define PINCFGx_PULLEN_Msk(pin) (1UL << (PINCFGx_PULLEN_Pos(pin)))
 
+#ifdef WHAL_CFG_GPIO_API_MAPPING_PIC32CZ
+#define whal_Pic32czGpio_Init   whal_Gpio_Init
+#define whal_Pic32czGpio_Deinit whal_Gpio_Deinit
+#define whal_Pic32czGpio_Get    whal_Gpio_Get
+#define whal_Pic32czGpio_Set    whal_Gpio_Set
+#endif /* WHAL_CFG_GPIO_API_MAPPING_PIC32CZ */
+
 whal_Error whal_Pic32czGpio_Init(whal_Gpio *gpioDev)
 {
     if (!gpioDev || !gpioDev->cfg) {
@@ -187,9 +194,11 @@ whal_Error whal_Pic32czGpio_Set(whal_Gpio *gpioDev, size_t pin, size_t value)
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_GPIO_API_MAPPING_PIC32CZ
 const whal_GpioDriver whal_Pic32czGpio_Driver = {
     .Init = whal_Pic32czGpio_Init,
     .Deinit = whal_Pic32czGpio_Deinit,
     .Get = whal_Pic32czGpio_Get,
     .Set = whal_Pic32czGpio_Set,
 };
+#endif /* !WHAL_CFG_GPIO_API_MAPPING_PIC32CZ */
diff --git a/src/gpio/stm32wb_gpio.c b/src/gpio/stm32wb_gpio.c
index bd335cf..4bbb1f3 100644
--- a/src/gpio/stm32wb_gpio.c
+++ b/src/gpio/stm32wb_gpio.c
@@ -32,6 +32,16 @@
 /* Alternate function high register - 4 bits per pin for pins 8-15 */
 #define GPIO_ALTFNH_REG   0x24
 
+#if defined(WHAL_CFG_GPIO_API_MAPPING_STM32WB) || \
+    defined(WHAL_CFG_GPIO_API_MAPPING_STM32F4) || \
+    defined(WHAL_CFG_GPIO_API_MAPPING_STM32H5) || \
+    defined(WHAL_CFG_GPIO_API_MAPPING_STM32C0)
+#define whal_Stm32wbGpio_Init   whal_Gpio_Init
+#define whal_Stm32wbGpio_Deinit whal_Gpio_Deinit
+#define whal_Stm32wbGpio_Get    whal_Gpio_Get
+#define whal_Stm32wbGpio_Set    whal_Gpio_Set
+#endif /* WHAL_CFG_GPIO_API_MAPPING */
+
 /*
  * Configure alternate function for a pin.
  *
@@ -164,9 +174,14 @@ whal_Error whal_Stm32wbGpio_Set(whal_Gpio *gpioDev, size_t pin, size_t value)
     return whal_Stm32wbGpio_SetOrGet(gpioDev, pin, &value, 1);
 }
 
+#if !defined(WHAL_CFG_GPIO_API_MAPPING_STM32WB) && \
+    !defined(WHAL_CFG_GPIO_API_MAPPING_STM32F4) && \
+    !defined(WHAL_CFG_GPIO_API_MAPPING_STM32H5) && \
+    !defined(WHAL_CFG_GPIO_API_MAPPING_STM32C0)
 const whal_GpioDriver whal_Stm32wbGpio_Driver = {
     .Init = whal_Stm32wbGpio_Init,
     .Deinit = whal_Stm32wbGpio_Deinit,
     .Get = whal_Stm32wbGpio_Get,
     .Set = whal_Stm32wbGpio_Set,
 };
+#endif /* !WHAL_CFG_GPIO_API_MAPPING */
diff --git a/src/i2c/stm32wb_i2c.c b/src/i2c/stm32wb_i2c.c
index 3ec2c91..c6cde78 100644
--- a/src/i2c/stm32wb_i2c.c
+++ b/src/i2c/stm32wb_i2c.c
@@ -121,6 +121,14 @@
 #define I2C_FMP_TLOW_NS    500   /* Fast mode plus tLOW min */
 #define I2C_FMP_THIGH_NS   260   /* Fast mode plus tHIGH min */
 
+#ifdef WHAL_CFG_I2C_API_MAPPING_STM32WB
+#define whal_Stm32wbI2c_Init     whal_I2c_Init
+#define whal_Stm32wbI2c_Deinit   whal_I2c_Deinit
+#define whal_Stm32wbI2c_StartCom whal_I2c_StartCom
+#define whal_Stm32wbI2c_EndCom   whal_I2c_EndCom
+#define whal_Stm32wbI2c_Transfer whal_I2c_Transfer
+#endif /* WHAL_CFG_I2C_API_MAPPING_STM32WB */
+
 static uint32_t Stm32wbI2c_CalcTimingr(uint32_t pclk, uint32_t freq)
 {
     uint32_t tLowNs, tHighNs;
@@ -500,6 +508,7 @@ whal_Error whal_Stm32wbI2c_Transfer(whal_I2c *i2cDev, whal_I2c_Msg *msgs,
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_I2C_API_MAPPING_STM32WB
 const whal_I2cDriver whal_Stm32wbI2c_Driver = {
     .Init = whal_Stm32wbI2c_Init,
     .Deinit = whal_Stm32wbI2c_Deinit,
@@ -507,3 +516,4 @@ const whal_I2cDriver whal_Stm32wbI2c_Driver = {
     .EndCom = whal_Stm32wbI2c_EndCom,
     .Transfer = whal_Stm32wbI2c_Transfer,
 };
+#endif /* !WHAL_CFG_I2C_API_MAPPING_STM32WB */
diff --git a/src/irq/cortex_m4_nvic.c b/src/irq/cortex_m4_nvic.c
index 9685f80..a248bf7 100644
--- a/src/irq/cortex_m4_nvic.c
+++ b/src/irq/cortex_m4_nvic.c
@@ -14,7 +14,14 @@
 #define NVIC_IPR_REG(irq)    (0x300 + (((irq) >> 2) << 2))
 #define NVIC_IPR_SHIFT(irq)  (((irq) & 0x3) << 3)
 
-static whal_Error whal_Nvic_Init(whal_Irq *irqDev)
+#ifdef WHAL_CFG_IRQ_API_MAPPING_NVIC
+#define whal_Nvic_Init    whal_Irq_Init
+#define whal_Nvic_Deinit  whal_Irq_Deinit
+#define whal_Nvic_Enable  whal_Irq_Enable
+#define whal_Nvic_Disable whal_Irq_Disable
+#endif /* WHAL_CFG_IRQ_API_MAPPING_NVIC */
+
+whal_Error whal_Nvic_Init(whal_Irq *irqDev)
 {
     if (!irqDev) {
         return WHAL_EINVAL;
@@ -23,7 +30,7 @@ static whal_Error whal_Nvic_Init(whal_Irq *irqDev)
     return WHAL_SUCCESS;
 }
 
-static whal_Error whal_Nvic_Deinit(whal_Irq *irqDev)
+whal_Error whal_Nvic_Deinit(whal_Irq *irqDev)
 {
     if (!irqDev) {
         return WHAL_EINVAL;
@@ -32,7 +39,7 @@ static whal_Error whal_Nvic_Deinit(whal_Irq *irqDev)
     return WHAL_SUCCESS;
 }
 
-static whal_Error whal_Nvic_Enable(whal_Irq *irqDev, size_t irq,
+whal_Error whal_Nvic_Enable(whal_Irq *irqDev, size_t irq,
                                     const void *irqCfg)
 {
     if (!irqDev) {
@@ -56,7 +63,7 @@ static whal_Error whal_Nvic_Enable(whal_Irq *irqDev, size_t irq,
     return WHAL_SUCCESS;
 }
 
-static whal_Error whal_Nvic_Disable(whal_Irq *irqDev, size_t irq)
+whal_Error whal_Nvic_Disable(whal_Irq *irqDev, size_t irq)
 {
     if (!irqDev) {
         return WHAL_EINVAL;
@@ -69,9 +76,11 @@ static whal_Error whal_Nvic_Disable(whal_Irq *irqDev, size_t irq)
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_IRQ_API_MAPPING_NVIC
 const whal_IrqDriver whal_Nvic_Driver = {
     .Init = whal_Nvic_Init,
     .Deinit = whal_Nvic_Deinit,
     .Enable = whal_Nvic_Enable,
     .Disable = whal_Nvic_Disable,
 };
+#endif /* !WHAL_CFG_IRQ_API_MAPPING_NVIC */
diff --git a/src/rng/rng.c b/src/rng/rng.c
index 2682ab4..df18d97 100644
--- a/src/rng/rng.c
+++ b/src/rng/rng.c
@@ -4,27 +4,30 @@
 
 inline whal_Error whal_Rng_Init(whal_Rng *rngDev)
 {
-    if (!rngDev || !rngDev->driver || !rngDev->driver->Init) {
+    if (!rngDev)
         return WHAL_EINVAL;
-    }
+    if (!rngDev->driver || !rngDev->driver->Init)
+        return WHAL_ENOTIMPL;
 
     return rngDev->driver->Init(rngDev);
 }
 
 inline whal_Error whal_Rng_Deinit(whal_Rng *rngDev)
 {
-    if (!rngDev || !rngDev->driver || !rngDev->driver->Deinit) {
+    if (!rngDev)
         return WHAL_EINVAL;
-    }
+    if (!rngDev->driver || !rngDev->driver->Deinit)
+        return WHAL_ENOTIMPL;
 
     return rngDev->driver->Deinit(rngDev);
 }
 
 inline whal_Error whal_Rng_Generate(whal_Rng *rngDev, void *rngData, size_t rngDataSz)
 {
-    if (!rngDev || !rngDev->driver || !rngDev->driver->Generate || !rngData) {
+    if (!rngDev || !rngData)
         return WHAL_EINVAL;
-    }
+    if (!rngDev->driver || !rngDev->driver->Generate)
+        return WHAL_ENOTIMPL;
 
     return rngDev->driver->Generate(rngDev, rngData, rngDataSz);
 }
diff --git a/src/rng/stm32h5_rng.c b/src/rng/stm32h5_rng.c
index 6879e3c..6bdd126 100644
--- a/src/rng/stm32h5_rng.c
+++ b/src/rng/stm32h5_rng.c
@@ -55,6 +55,12 @@
 /* Magic value required to unlock HTCR writes */
 #define RNG_HTCR_MAGIC     0x17590ABCUL
 
+#ifdef WHAL_CFG_RNG_API_MAPPING_STM32H5
+#define whal_Stm32h5Rng_Init     whal_Rng_Init
+#define whal_Stm32h5Rng_Deinit   whal_Rng_Deinit
+#define whal_Stm32h5Rng_Generate whal_Rng_Generate
+#endif /* WHAL_CFG_RNG_API_MAPPING_STM32H5 */
+
 whal_Error whal_Stm32h5Rng_Init(whal_Rng *rngDev)
 {
     whal_Stm32h5Rng_Cfg *cfg;
@@ -158,8 +164,10 @@ whal_Error whal_Stm32h5Rng_Generate(whal_Rng *rngDev, void *rngData,
     return err;
 }
 
+#ifndef WHAL_CFG_RNG_API_MAPPING_STM32H5
 const whal_RngDriver whal_Stm32h5Rng_Driver = {
     .Init = whal_Stm32h5Rng_Init,
     .Deinit = whal_Stm32h5Rng_Deinit,
     .Generate = whal_Stm32h5Rng_Generate,
 };
+#endif /* !WHAL_CFG_RNG_API_MAPPING_STM32H5 */
diff --git a/src/rng/stm32wb_rng.c b/src/rng/stm32wb_rng.c
index 1c2a36c..5cd1218 100644
--- a/src/rng/stm32wb_rng.c
+++ b/src/rng/stm32wb_rng.c
@@ -41,6 +41,12 @@
 /* Data Register - 32-bit random value */
 #define RNG_DR_REG  0x08
 
+#ifdef WHAL_CFG_RNG_API_MAPPING_STM32WB
+#define whal_Stm32wbRng_Init     whal_Rng_Init
+#define whal_Stm32wbRng_Deinit   whal_Rng_Deinit
+#define whal_Stm32wbRng_Generate whal_Rng_Generate
+#endif /* WHAL_CFG_RNG_API_MAPPING_STM32WB */
+
 whal_Error whal_Stm32wbRng_Init(whal_Rng *rngDev)
 {
     if (!rngDev || !rngDev->cfg) {
@@ -124,8 +130,10 @@ whal_Error whal_Stm32wbRng_Generate(whal_Rng *rngDev, void *rngData, size_t rngD
     return err;
 }
 
+#ifndef WHAL_CFG_RNG_API_MAPPING_STM32WB
 const whal_RngDriver whal_Stm32wbRng_Driver = {
     .Init = whal_Stm32wbRng_Init,
     .Deinit = whal_Stm32wbRng_Deinit,
     .Generate = whal_Stm32wbRng_Generate,
 };
+#endif /* !WHAL_CFG_RNG_API_MAPPING_STM32WB */
diff --git a/src/sensor/imu/bmi270_sensor.c b/src/sensor/imu/bmi270_sensor.c
index a310ad6..f98c0e5 100644
--- a/src/sensor/imu/bmi270_sensor.c
+++ b/src/sensor/imu/bmi270_sensor.c
@@ -33,6 +33,12 @@
 /* Number of raw data bytes: accel (6) + gyro (6) */
 #define BMI270_DATA_LEN  12
 
+#ifdef WHAL_CFG_SENSOR_API_MAPPING_BMI270
+#define whal_Bmi270_Init   whal_Sensor_Init
+#define whal_Bmi270_Deinit whal_Sensor_Deinit
+#define whal_Bmi270_Read   whal_Sensor_Read
+#endif /* WHAL_CFG_SENSOR_API_MAPPING_BMI270 */
+
 whal_Error whal_Bmi270_Init(whal_Sensor *dev)
 {
     whal_Bmi270_Cfg *cfg;
@@ -210,8 +216,10 @@ whal_Error whal_Bmi270_Read(whal_Sensor *dev, void *data)
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_SENSOR_API_MAPPING_BMI270
 const whal_SensorDriver whal_Bmi270_Driver = {
     .Init = whal_Bmi270_Init,
     .Deinit = whal_Bmi270_Deinit,
     .Read = whal_Bmi270_Read,
 };
+#endif /* !WHAL_CFG_SENSOR_API_MAPPING_BMI270 */
diff --git a/src/spi/spi.c b/src/spi/spi.c
index a259194..0394b76 100644
--- a/src/spi/spi.c
+++ b/src/spi/spi.c
@@ -4,45 +4,50 @@
 
 inline whal_Error whal_Spi_Init(whal_Spi *spiDev)
 {
-    if (!spiDev || !spiDev->driver || !spiDev->driver->Init) {
+    if (!spiDev)
         return WHAL_EINVAL;
-    }
+    if (!spiDev->driver || !spiDev->driver->Init)
+        return WHAL_ENOTIMPL;
 
     return spiDev->driver->Init(spiDev);
 }
 
 inline whal_Error whal_Spi_Deinit(whal_Spi *spiDev)
 {
-    if (!spiDev || !spiDev->driver || !spiDev->driver->Deinit) {
+    if (!spiDev)
         return WHAL_EINVAL;
-    }
+    if (!spiDev->driver || !spiDev->driver->Deinit)
+        return WHAL_ENOTIMPL;
 
     return spiDev->driver->Deinit(spiDev);
 }
 
 inline whal_Error whal_Spi_StartCom(whal_Spi *spiDev, whal_Spi_ComCfg *comCfg)
 {
-    if (!spiDev || !spiDev->driver || !spiDev->driver->StartCom || !comCfg) {
+    if (!spiDev || !comCfg)
         return WHAL_EINVAL;
-    }
+    if (!spiDev->driver || !spiDev->driver->StartCom)
+        return WHAL_ENOTIMPL;
 
     return spiDev->driver->StartCom(spiDev, comCfg);
 }
 
 inline whal_Error whal_Spi_EndCom(whal_Spi *spiDev)
 {
-    if (!spiDev || !spiDev->driver || !spiDev->driver->EndCom) {
+    if (!spiDev)
         return WHAL_EINVAL;
-    }
+    if (!spiDev->driver || !spiDev->driver->EndCom)
+        return WHAL_ENOTIMPL;
 
     return spiDev->driver->EndCom(spiDev);
 }
 
 inline whal_Error whal_Spi_SendRecv(whal_Spi *spiDev, const void *tx, size_t txLen, void *rx, size_t rxLen)
 {
-    if (!spiDev || !spiDev->driver || !spiDev->driver->SendRecv) {
+    if (!spiDev)
         return WHAL_EINVAL;
-    }
+    if (!spiDev->driver || !spiDev->driver->SendRecv)
+        return WHAL_ENOTIMPL;
 
     return spiDev->driver->SendRecv(spiDev, tx, txLen, rx, rxLen);
 }
diff --git a/src/spi/stm32f4_spi.c b/src/spi/stm32f4_spi.c
index 16e1dd4..4a1ba37 100644
--- a/src/spi/stm32f4_spi.c
+++ b/src/spi/stm32f4_spi.c
@@ -56,6 +56,14 @@
 /* Data Register - 8/16-bit access */
 #define SPI_DR_REG  0x0C
 
+#ifdef WHAL_CFG_SPI_API_MAPPING_STM32F4
+#define whal_Stm32f4Spi_Init     whal_Spi_Init
+#define whal_Stm32f4Spi_Deinit   whal_Spi_Deinit
+#define whal_Stm32f4Spi_StartCom whal_Spi_StartCom
+#define whal_Stm32f4Spi_EndCom   whal_Spi_EndCom
+#define whal_Stm32f4Spi_SendRecv whal_Spi_SendRecv
+#endif /* WHAL_CFG_SPI_API_MAPPING_STM32F4 */
+
 /*
  * Calculate the baud rate prescaler index for a target baud rate.
  *
@@ -219,6 +227,7 @@ whal_Error whal_Stm32f4Spi_SendRecv(whal_Spi *spiDev,
                              cfg->timeout);
 }
 
+#ifndef WHAL_CFG_SPI_API_MAPPING_STM32F4
 const whal_SpiDriver whal_Stm32f4Spi_Driver = {
     .Init = whal_Stm32f4Spi_Init,
     .Deinit = whal_Stm32f4Spi_Deinit,
@@ -226,3 +235,4 @@ const whal_SpiDriver whal_Stm32f4Spi_Driver = {
     .EndCom = whal_Stm32f4Spi_EndCom,
     .SendRecv = whal_Stm32f4Spi_SendRecv,
 };
+#endif /* !WHAL_CFG_SPI_API_MAPPING_STM32F4 */
diff --git a/src/spi/stm32h5_spi.c b/src/spi/stm32h5_spi.c
index 150f2d0..9c2ccae 100644
--- a/src/spi/stm32h5_spi.c
+++ b/src/spi/stm32h5_spi.c
@@ -89,6 +89,14 @@
 #define SPI_TXDR_REG 0x020
 #define SPI_RXDR_REG 0x030
 
+#ifdef WHAL_CFG_SPI_API_MAPPING_STM32H5
+#define whal_Stm32h5Spi_Init     whal_Spi_Init
+#define whal_Stm32h5Spi_Deinit   whal_Spi_Deinit
+#define whal_Stm32h5Spi_StartCom whal_Spi_StartCom
+#define whal_Stm32h5Spi_EndCom   whal_Spi_EndCom
+#define whal_Stm32h5Spi_SendRecv whal_Spi_SendRecv
+#endif /* WHAL_CFG_SPI_API_MAPPING_STM32H5 */
+
 /*
  * Calculate the baud rate prescaler index for a target baud rate.
  * SPI baud rate = fPCLK / (2 ^ (MBR + 1))
@@ -269,6 +277,7 @@ whal_Error whal_Stm32h5Spi_SendRecv(whal_Spi *spiDev,
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_SPI_API_MAPPING_STM32H5
 const whal_SpiDriver whal_Stm32h5Spi_Driver = {
     .Init = whal_Stm32h5Spi_Init,
     .Deinit = whal_Stm32h5Spi_Deinit,
@@ -276,3 +285,4 @@ const whal_SpiDriver whal_Stm32h5Spi_Driver = {
     .EndCom = whal_Stm32h5Spi_EndCom,
     .SendRecv = whal_Stm32h5Spi_SendRecv,
 };
+#endif /* !WHAL_CFG_SPI_API_MAPPING_STM32H5 */
diff --git a/src/spi/stm32wb_spi.c b/src/spi/stm32wb_spi.c
index b08b8d4..c5e2641 100644
--- a/src/spi/stm32wb_spi.c
+++ b/src/spi/stm32wb_spi.c
@@ -60,6 +60,15 @@
 #define SPI_DR_Pos 0
 #define SPI_DR_Msk (WHAL_BITMASK(8) << SPI_DR_Pos)
 
+#if defined(WHAL_CFG_SPI_API_MAPPING_STM32WB) || \
+    defined(WHAL_CFG_SPI_API_MAPPING_STM32C0)
+#define whal_Stm32wbSpi_Init     whal_Spi_Init
+#define whal_Stm32wbSpi_Deinit   whal_Spi_Deinit
+#define whal_Stm32wbSpi_StartCom whal_Spi_StartCom
+#define whal_Stm32wbSpi_EndCom   whal_Spi_EndCom
+#define whal_Stm32wbSpi_SendRecv whal_Spi_SendRecv
+#endif /* WHAL_CFG_SPI_API_MAPPING */
+
 /*
  * Calculate the baud rate prescaler index for a target baud rate.
  *
@@ -239,6 +248,8 @@ whal_Error whal_Stm32wbSpi_SendRecv(whal_Spi *spiDev,
                              cfg->timeout);
 }
 
+#if !defined(WHAL_CFG_SPI_API_MAPPING_STM32WB) && \
+    !defined(WHAL_CFG_SPI_API_MAPPING_STM32C0)
 const whal_SpiDriver whal_Stm32wbSpi_Driver = {
     .Init = whal_Stm32wbSpi_Init,
     .Deinit = whal_Stm32wbSpi_Deinit,
@@ -246,3 +257,4 @@ const whal_SpiDriver whal_Stm32wbSpi_Driver = {
     .EndCom = whal_Stm32wbSpi_EndCom,
     .SendRecv = whal_Stm32wbSpi_SendRecv,
 };
+#endif /* !WHAL_CFG_SPI_API_MAPPING */
diff --git a/src/supply/pic32cz_supc.c b/src/supply/pic32cz_supc.c
index 9c31d1e..f57126b 100644
--- a/src/supply/pic32cz_supc.c
+++ b/src/supply/pic32cz_supc.c
@@ -6,6 +6,12 @@
 #define VREGCTRL_AVREGEN_Pos 16
 #define VREGCTRL_AVREGEN_Msk (WHAL_BITMASK(3) << VREGCTRL_AVREGEN_Pos)
 
+#ifdef WHAL_CFG_SUPPLY_API_MAPPING_PIC32CZ
+#define whal_Pic32czSupc_Init    whal_Supply_Init
+#define whal_Pic32czSupc_Deinit  whal_Supply_Deinit
+#define whal_Pic32czSupc_Enable  whal_Supply_Enable
+#define whal_Pic32czSupc_Disable whal_Supply_Disable
+#endif /* WHAL_CFG_SUPPLY_API_MAPPING_PIC32CZ */
 
 whal_Error whal_Pic32czSupc_Init(whal_Supply *supplyCtrl)
 {
@@ -45,9 +51,11 @@ whal_Error whal_Pic32czSupc_Disable(whal_Supply *supplyCtrl, void *supply)
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_SUPPLY_API_MAPPING_PIC32CZ
 const whal_SupplyDriver whal_Pic32czSupc_Driver = {
     .Init = whal_Pic32czSupc_Init,
     .Deinit = whal_Pic32czSupc_Deinit,
     .Enable = whal_Pic32czSupc_Enable,
     .Disable = whal_Pic32czSupc_Disable,
 };
+#endif /* !WHAL_CFG_SUPPLY_API_MAPPING_PIC32CZ */
diff --git a/src/timer/systick.c b/src/timer/systick.c
index 5dc5917..f4df8d3 100644
--- a/src/timer/systick.c
+++ b/src/timer/systick.c
@@ -20,7 +20,15 @@
 #define SYSTICK_RVR_RELOAD_Pos 0
 #define SYSTICK_RVR_RELOAD_Msk (WHAL_BITMASK(24) << SYSTICK_RVR_RELOAD_Pos)
 
-whal_Error SysTick_Init(whal_Timer *timerDev)
+#ifdef WHAL_CFG_TIMER_API_MAPPING_SYSTICK
+#define whal_SysTick_Init   whal_Timer_Init
+#define whal_SysTick_Deinit whal_Timer_Deinit
+#define whal_SysTick_Start  whal_Timer_Start
+#define whal_SysTick_Stop   whal_Timer_Stop
+#define whal_SysTick_Reset  whal_Timer_Reset
+#endif /* WHAL_CFG_TIMER_API_MAPPING_SYSTICK */
+
+whal_Error whal_SysTick_Init(whal_Timer *timerDev)
 {
     whal_SysTick_Cfg *cfg;
     const whal_Regmap *reg = &timerDev->regmap;
@@ -43,12 +51,12 @@ whal_Error SysTick_Init(whal_Timer *timerDev)
     return WHAL_SUCCESS;
 }
 
-whal_Error SysTick_Deinit(whal_Timer *timerDev)
+whal_Error whal_SysTick_Deinit(whal_Timer *timerDev)
 {
     return WHAL_SUCCESS;
 }
 
-whal_Error SysTick_Start(whal_Timer *timerDev)
+whal_Error whal_SysTick_Start(whal_Timer *timerDev)
 {
     const whal_Regmap *reg = &timerDev->regmap;
 
@@ -62,7 +70,7 @@ whal_Error SysTick_Start(whal_Timer *timerDev)
     return WHAL_SUCCESS;
 }
 
-whal_Error SysTick_Stop(whal_Timer *timerDev)
+whal_Error whal_SysTick_Stop(whal_Timer *timerDev)
 {
     const whal_Regmap *reg = &timerDev->regmap;
 
@@ -76,16 +84,18 @@ whal_Error SysTick_Stop(whal_Timer *timerDev)
     return WHAL_SUCCESS;
 }
 
-whal_Error SysTick_Reset(whal_Timer *timerDev)
+whal_Error whal_SysTick_Reset(whal_Timer *timerDev)
 {
 
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_TIMER_API_MAPPING_SYSTICK
 const whal_TimerDriver whal_SysTick_Driver = {
-    .Init = SysTick_Init,
-    .Deinit = SysTick_Deinit,
-    .Start = SysTick_Start,
-    .Stop = SysTick_Stop,
-    .Reset = SysTick_Reset,
+    .Init = whal_SysTick_Init,
+    .Deinit = whal_SysTick_Deinit,
+    .Start = whal_SysTick_Start,
+    .Stop = whal_SysTick_Stop,
+    .Reset = whal_SysTick_Reset,
 };
+#endif /* !WHAL_CFG_TIMER_API_MAPPING_SYSTICK */
diff --git a/src/timer/timer.c b/src/timer/timer.c
index c4e1933..c8ef860 100644
--- a/src/timer/timer.c
+++ b/src/timer/timer.c
@@ -5,45 +5,50 @@
 
 inline whal_Error whal_Timer_Init(whal_Timer *timerDev)
 {
-    if (!timerDev || !timerDev->driver || !timerDev->driver->Init) {
+    if (!timerDev)
         return WHAL_EINVAL;
-    }
+    if (!timerDev->driver || !timerDev->driver->Init)
+        return WHAL_ENOTIMPL;
 
     return timerDev->driver->Init(timerDev);
 }
 
 inline whal_Error whal_Timer_Deinit(whal_Timer *timerDev)
 {
-    if (!timerDev || !timerDev->driver || !timerDev->driver->Deinit) {
+    if (!timerDev)
         return WHAL_EINVAL;
-    }
+    if (!timerDev->driver || !timerDev->driver->Deinit)
+        return WHAL_ENOTIMPL;
 
     return timerDev->driver->Deinit(timerDev);
 }
 
 inline whal_Error whal_Timer_Start(whal_Timer *timerDev)
 {
-    if (!timerDev || !timerDev->driver || !timerDev->driver->Start) {
+    if (!timerDev)
         return WHAL_EINVAL;
-    }
+    if (!timerDev->driver || !timerDev->driver->Start)
+        return WHAL_ENOTIMPL;
 
     return timerDev->driver->Start(timerDev);
 }
 
 inline whal_Error whal_Timer_Stop(whal_Timer *timerDev)
 {
-    if (!timerDev || !timerDev->driver || !timerDev->driver->Stop) {
+    if (!timerDev)
         return WHAL_EINVAL;
-    }
+    if (!timerDev->driver || !timerDev->driver->Stop)
+        return WHAL_ENOTIMPL;
 
     return timerDev->driver->Stop(timerDev);
 }
 
 inline whal_Error whal_Timer_Reset(whal_Timer *timerDev)
 {
-    if (!timerDev || !timerDev->driver || !timerDev->driver->Reset) {
+    if (!timerDev)
         return WHAL_EINVAL;
-    }
+    if (!timerDev->driver || !timerDev->driver->Reset)
+        return WHAL_ENOTIMPL;
 
     return timerDev->driver->Reset(timerDev);
 }
diff --git a/src/uart/pic32cz_uart.c b/src/uart/pic32cz_uart.c
index d3e9b47..c87ded4 100644
--- a/src/uart/pic32cz_uart.c
+++ b/src/uart/pic32cz_uart.c
@@ -159,6 +159,15 @@
 #define USART_DATA_Pos              0
 #define USART_DATA_Msk              (WHAL_BITMASK(9) << USART_DATA_Pos)
 
+#ifdef WHAL_CFG_UART_API_MAPPING_PIC32CZ
+#define whal_Pic32czUart_Init      whal_Uart_Init
+#define whal_Pic32czUart_Deinit    whal_Uart_Deinit
+#define whal_Pic32czUart_Send      whal_Uart_Send
+#define whal_Pic32czUart_Recv      whal_Uart_Recv
+#define whal_Pic32czUart_SendAsync whal_Uart_SendAsync
+#define whal_Pic32czUart_RecvAsync whal_Uart_RecvAsync
+#endif /* WHAL_CFG_UART_API_MAPPING_PIC32CZ */
+
 whal_Error whal_Pic32czUart_Init(whal_Uart *uartDev)
 {
     whal_Error err;
@@ -351,9 +360,29 @@ whal_Error whal_Pic32czUart_Recv(whal_Uart *uartDev, void *data, size_t dataSz)
     return WHAL_SUCCESS;
 }
 
+whal_Error whal_Pic32czUart_SendAsync(whal_Uart *uartDev, const void *data, size_t dataSz)
+{
+    (void)dataSz;
+    if (!uartDev || !data)
+        return WHAL_EINVAL;
+    return WHAL_ENOTIMPL;
+}
+
+whal_Error whal_Pic32czUart_RecvAsync(whal_Uart *uartDev, void *data, size_t dataSz)
+{
+    (void)dataSz;
+    if (!uartDev || !data)
+        return WHAL_EINVAL;
+    return WHAL_ENOTIMPL;
+}
+
+#ifndef WHAL_CFG_UART_API_MAPPING_PIC32CZ
 const whal_UartDriver whal_Pic32czUart_Driver = {
     .Init = whal_Pic32czUart_Init,
     .Deinit = whal_Pic32czUart_Deinit,
     .Send = whal_Pic32czUart_Send,
     .Recv = whal_Pic32czUart_Recv,
+    .SendAsync = whal_Pic32czUart_SendAsync,
+    .RecvAsync = whal_Pic32czUart_RecvAsync,
 };
+#endif /* !WHAL_CFG_UART_API_MAPPING_PIC32CZ */
diff --git a/src/uart/stm32f4_uart.c b/src/uart/stm32f4_uart.c
index f5905b4..d35e485 100644
--- a/src/uart/stm32f4_uart.c
+++ b/src/uart/stm32f4_uart.c
@@ -45,6 +45,15 @@
 #define UART_CR1_UE_Pos 13                                             /* USART enable */
 #define UART_CR1_UE_Msk (1UL << UART_CR1_UE_Pos)
 
+#ifdef WHAL_CFG_UART_API_MAPPING_STM32F4
+#define whal_Stm32f4Uart_Init      whal_Uart_Init
+#define whal_Stm32f4Uart_Deinit    whal_Uart_Deinit
+#define whal_Stm32f4Uart_Send      whal_Uart_Send
+#define whal_Stm32f4Uart_Recv      whal_Uart_Recv
+#define whal_Stm32f4Uart_SendAsync whal_Uart_SendAsync
+#define whal_Stm32f4Uart_RecvAsync whal_Uart_RecvAsync
+#endif /* WHAL_CFG_UART_API_MAPPING_STM32F4 */
+
 whal_Error whal_Stm32f4Uart_Init(whal_Uart *uartDev)
 {
     whal_Stm32f4Uart_Cfg *cfg;
@@ -157,9 +166,29 @@ whal_Error whal_Stm32f4Uart_Recv(whal_Uart *uartDev, void *data, size_t dataSz)
     return WHAL_SUCCESS;
 }
 
+whal_Error whal_Stm32f4Uart_SendAsync(whal_Uart *uartDev, const void *data, size_t dataSz)
+{
+    (void)dataSz;
+    if (!uartDev || !data)
+        return WHAL_EINVAL;
+    return WHAL_ENOTIMPL;
+}
+
+whal_Error whal_Stm32f4Uart_RecvAsync(whal_Uart *uartDev, void *data, size_t dataSz)
+{
+    (void)dataSz;
+    if (!uartDev || !data)
+        return WHAL_EINVAL;
+    return WHAL_ENOTIMPL;
+}
+
+#ifndef WHAL_CFG_UART_API_MAPPING_STM32F4
 const whal_UartDriver whal_Stm32f4Uart_Driver = {
     .Init = whal_Stm32f4Uart_Init,
     .Deinit = whal_Stm32f4Uart_Deinit,
     .Send = whal_Stm32f4Uart_Send,
+    .SendAsync = whal_Stm32f4Uart_SendAsync,
+    .RecvAsync = whal_Stm32f4Uart_RecvAsync,
     .Recv = whal_Stm32f4Uart_Recv,
 };
+#endif /* !WHAL_CFG_UART_API_MAPPING_STM32F4 */
diff --git a/src/uart/stm32wb_uart.c b/src/uart/stm32wb_uart.c
index 75f4b8a..6789872 100644
--- a/src/uart/stm32wb_uart.c
+++ b/src/uart/stm32wb_uart.c
@@ -38,6 +38,22 @@
 #define UART_TDR_Pos 0
 #define UART_TDR_Msk (WHAL_BITMASK(9) << UART_TDR_Pos)
 
+#if defined(WHAL_CFG_UART_API_MAPPING_STM32WB) || \
+    defined(WHAL_CFG_UART_API_MAPPING_STM32H5) || \
+    defined(WHAL_CFG_UART_API_MAPPING_STM32C0)
+#define whal_Stm32wbUart_Init      whal_Uart_Init
+#define whal_Stm32wbUart_Deinit    whal_Uart_Deinit
+#define whal_Stm32wbUart_Send      whal_Uart_Send
+#define whal_Stm32wbUart_Recv      whal_Uart_Recv
+#define whal_Stm32wbUart_SendAsync whal_Uart_SendAsync
+#define whal_Stm32wbUart_RecvAsync whal_Uart_RecvAsync
+#endif /* WHAL_CFG_UART_API_MAPPING */
+
+#ifdef WHAL_CFG_UART_API_MAPPING_STM32WB_DMA
+#define whal_Stm32wbUart_Init   whal_Uart_Init
+#define whal_Stm32wbUart_Deinit whal_Uart_Deinit
+#endif /* WHAL_CFG_UART_API_MAPPING_STM32WB_DMA */
+
 whal_Error whal_Stm32wbUart_Init(whal_Uart *uartDev)
 {
     whal_Stm32wbUart_Cfg *cfg;
@@ -145,10 +161,33 @@ whal_Error whal_Stm32wbUart_Recv(whal_Uart *uartDev, void *data, size_t dataSz)
     return WHAL_SUCCESS;
 }
 
+whal_Error whal_Stm32wbUart_SendAsync(whal_Uart *uartDev, const void *data, size_t dataSz)
+{
+    (void)dataSz;
+    if (!uartDev || !data)
+        return WHAL_EINVAL;
+    return WHAL_ENOTIMPL;
+}
+
+whal_Error whal_Stm32wbUart_RecvAsync(whal_Uart *uartDev, void *data, size_t dataSz)
+{
+    (void)dataSz;
+    if (!uartDev || !data)
+        return WHAL_EINVAL;
+    return WHAL_ENOTIMPL;
+}
+
+#if !defined(WHAL_CFG_UART_API_MAPPING_STM32WB) && \
+    !defined(WHAL_CFG_UART_API_MAPPING_STM32WB_DMA) && \
+    !defined(WHAL_CFG_UART_API_MAPPING_STM32H5) && \
+    !defined(WHAL_CFG_UART_API_MAPPING_STM32C0)
 const whal_UartDriver whal_Stm32wbUart_Driver = {
     .Init = whal_Stm32wbUart_Init,
     .Deinit = whal_Stm32wbUart_Deinit,
     .Send = whal_Stm32wbUart_Send,
     .Recv = whal_Stm32wbUart_Recv,
+    .SendAsync = whal_Stm32wbUart_SendAsync,
+    .RecvAsync = whal_Stm32wbUart_RecvAsync,
 };
+#endif /* !WHAL_CFG_UART_API_MAPPING */
 
diff --git a/src/uart/stm32wb_uart_dma.c b/src/uart/stm32wb_uart_dma.c
index c6a4bdb..ac9ad42 100644
--- a/src/uart/stm32wb_uart_dma.c
+++ b/src/uart/stm32wb_uart_dma.c
@@ -22,6 +22,19 @@
 
 #define UART_TDR_REG 0x28
 
+#if defined(WHAL_CFG_UART_API_MAPPING_STM32WB) || \
+    defined(WHAL_CFG_UART_API_MAPPING_STM32WB_DMA)
+#define whal_Stm32wbUart_Init   whal_Uart_Init
+#define whal_Stm32wbUart_Deinit whal_Uart_Deinit
+#endif
+
+#ifdef WHAL_CFG_UART_API_MAPPING_STM32WB_DMA
+#define whal_Stm32wbUartDma_Send      whal_Uart_Send
+#define whal_Stm32wbUartDma_Recv      whal_Uart_Recv
+#define whal_Stm32wbUartDma_SendAsync whal_Uart_SendAsync
+#define whal_Stm32wbUartDma_RecvAsync whal_Uart_RecvAsync
+#endif /* WHAL_CFG_UART_API_MAPPING_STM32WB_DMA */
+
 whal_Error whal_Stm32wbUartDma_SendAsync(whal_Uart *uartDev, const void *data,
                                          size_t dataSz)
 {
@@ -190,6 +203,7 @@ void whal_Stm32wbUartDma_RxCallback(void *ctx, whal_Error err)
     cfg->rxResult = err;
 }
 
+#ifndef WHAL_CFG_UART_API_MAPPING_STM32WB_DMA
 const whal_UartDriver whal_Stm32wbUartDma_Driver = {
     .Init = whal_Stm32wbUart_Init,
     .Deinit = whal_Stm32wbUart_Deinit,
@@ -198,3 +212,5 @@ const whal_UartDriver whal_Stm32wbUartDma_Driver = {
     .SendAsync = whal_Stm32wbUartDma_SendAsync,
     .RecvAsync = whal_Stm32wbUartDma_RecvAsync,
 };
+#endif /* !WHAL_CFG_UART_API_MAPPING_STM32WB_DMA */
+
diff --git a/src/uart/uart.c b/src/uart/uart.c
index a227459..8ed7a5b 100644
--- a/src/uart/uart.c
+++ b/src/uart/uart.c
@@ -4,54 +4,60 @@
 
 inline whal_Error whal_Uart_Init(whal_Uart *uartDev)
 {
-    if (!uartDev || !uartDev->driver || !uartDev->driver->Init) {
+    if (!uartDev)
         return WHAL_EINVAL;
-    }
+    if (!uartDev->driver || !uartDev->driver->Init)
+        return WHAL_ENOTIMPL;
 
     return uartDev->driver->Init(uartDev);
 }
 
 inline whal_Error whal_Uart_Deinit(whal_Uart *uartDev)
 {
-    if (!uartDev || !uartDev->driver || !uartDev->driver->Deinit) {
+    if (!uartDev)
         return WHAL_EINVAL;
-    }
+    if (!uartDev->driver || !uartDev->driver->Deinit)
+        return WHAL_ENOTIMPL;
 
     return uartDev->driver->Deinit(uartDev);
 }
 
 inline whal_Error whal_Uart_Send(whal_Uart *uartDev, const void *data, size_t dataSz)
 {
-    if (!uartDev || !uartDev->driver || !uartDev->driver->Send || !data) {
+    if (!uartDev || !data)
         return WHAL_EINVAL;
-    }
+    if (!uartDev->driver || !uartDev->driver->Send)
+        return WHAL_ENOTIMPL;
 
     return uartDev->driver->Send(uartDev, data, dataSz);
 }
 
 inline whal_Error whal_Uart_Recv(whal_Uart *uartDev, void *data, size_t dataSz)
 {
-    if (!uartDev || !uartDev->driver || !uartDev->driver->Recv || !data) {
+    if (!uartDev || !data)
         return WHAL_EINVAL;
-    }
+    if (!uartDev->driver || !uartDev->driver->Recv)
+        return WHAL_ENOTIMPL;
 
     return uartDev->driver->Recv(uartDev, data, dataSz);
 }
 
 inline whal_Error whal_Uart_SendAsync(whal_Uart *uartDev, const void *data, size_t dataSz)
 {
-    if (!uartDev || !uartDev->driver || !uartDev->driver->SendAsync || !data) {
+    if (!uartDev || !data)
         return WHAL_EINVAL;
-    }
+    if (!uartDev->driver || !uartDev->driver->SendAsync)
+        return WHAL_ENOTIMPL;
 
     return uartDev->driver->SendAsync(uartDev, data, dataSz);
 }
 
 inline whal_Error whal_Uart_RecvAsync(whal_Uart *uartDev, void *data, size_t dataSz)
 {
-    if (!uartDev || !uartDev->driver || !uartDev->driver->RecvAsync || !data) {
+    if (!uartDev || !data)
         return WHAL_EINVAL;
-    }
+    if (!uartDev->driver || !uartDev->driver->RecvAsync)
+        return WHAL_ENOTIMPL;
 
     return uartDev->driver->RecvAsync(uartDev, data, dataSz);
 }
diff --git a/src/watchdog/stm32wb_iwdg.c b/src/watchdog/stm32wb_iwdg.c
index 1cb40e8..ecb08d5 100644
--- a/src/watchdog/stm32wb_iwdg.c
+++ b/src/watchdog/stm32wb_iwdg.c
@@ -34,6 +34,12 @@
 #define IWDG_SR_RVU_Pos 1       /* Reload value update */
 #define IWDG_SR_RVU_Msk (1UL << IWDG_SR_RVU_Pos)
 
+#ifdef WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_IWDG
+#define whal_Stm32wbIwdg_Init    whal_Watchdog_Init
+#define whal_Stm32wbIwdg_Deinit  whal_Watchdog_Deinit
+#define whal_Stm32wbIwdg_Refresh whal_Watchdog_Refresh
+#endif /* WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_IWDG */
+
 whal_Error whal_Stm32wbIwdg_Init(whal_Watchdog *wdgDev)
 {
     const whal_Regmap *reg;
@@ -93,8 +99,10 @@ whal_Error whal_Stm32wbIwdg_Refresh(whal_Watchdog *wdgDev)
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_IWDG
 const whal_WatchdogDriver whal_Stm32wbIwdg_Driver = {
     .Init = whal_Stm32wbIwdg_Init,
     .Deinit = whal_Stm32wbIwdg_Deinit,
     .Refresh = whal_Stm32wbIwdg_Refresh,
 };
+#endif /* !WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_IWDG */
diff --git a/src/watchdog/stm32wb_wwdg.c b/src/watchdog/stm32wb_wwdg.c
index 520074b..55eede6 100644
--- a/src/watchdog/stm32wb_wwdg.c
+++ b/src/watchdog/stm32wb_wwdg.c
@@ -24,6 +24,12 @@
 #define CFR_WDGTB_Pos 11
 #define CFR_WDGTB_Msk (WHAL_BITMASK(3) << CFR_WDGTB_Pos)
 
+#ifdef WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_WWDG
+#define whal_Stm32wbWwdg_Init    whal_Watchdog_Init
+#define whal_Stm32wbWwdg_Deinit  whal_Watchdog_Deinit
+#define whal_Stm32wbWwdg_Refresh whal_Watchdog_Refresh
+#endif /* WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_WWDG */
+
 whal_Error whal_Stm32wbWwdg_Init(whal_Watchdog *wdgDev)
 {
     size_t base;
@@ -74,8 +80,10 @@ whal_Error whal_Stm32wbWwdg_Refresh(whal_Watchdog *wdgDev)
     return WHAL_SUCCESS;
 }
 
+#ifndef WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_WWDG
 const whal_WatchdogDriver whal_Stm32wbWwdg_Driver = {
     .Init = whal_Stm32wbWwdg_Init,
     .Deinit = whal_Stm32wbWwdg_Deinit,
     .Refresh = whal_Stm32wbWwdg_Refresh,
 };
+#endif /* !WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_WWDG */
diff --git a/tests/core/test_dispatch.c b/tests/core/test_dispatch.c
index 4a9f6b7..5385b7f 100644
--- a/tests/core/test_dispatch.c
+++ b/tests/core/test_dispatch.c
@@ -111,14 +111,14 @@ static void Test_Clock_NullDev(void)
 static void Test_Clock_NullDriver(void)
 {
     whal_Clock dev = { .driver = NULL };
-    WHAL_ASSERT_EQ(whal_Clock_Init(&dev), WHAL_EINVAL);
+    WHAL_ASSERT_EQ(whal_Clock_Init(&dev), WHAL_ENOTIMPL);
 }
 
 static void Test_Clock_NullVtableEntry(void)
 {
     static const whal_ClockDriver emptyDriver = { 0 };
     whal_Clock dev = { .driver = &emptyDriver };
-    WHAL_ASSERT_EQ(whal_Clock_Init(&dev), WHAL_EINVAL);
+    WHAL_ASSERT_EQ(whal_Clock_Init(&dev), WHAL_ENOTIMPL);
 }
 
 static void Test_Clock_ValidDispatch(void)
@@ -143,7 +143,7 @@ static void Test_Gpio_NullDev(void)
 static void Test_Gpio_NullDriver(void)
 {
     whal_Gpio dev = { .driver = NULL };
-    WHAL_ASSERT_EQ(whal_Gpio_Init(&dev), WHAL_EINVAL);
+    WHAL_ASSERT_EQ(whal_Gpio_Init(&dev), WHAL_ENOTIMPL);
 }
 
 static void Test_Gpio_ValidDispatch(void)
@@ -171,15 +171,15 @@ static void Test_Uart_NullDev(void)
 static void Test_Uart_NullDriver(void)
 {
     whal_Uart dev = { .driver = NULL };
-    WHAL_ASSERT_EQ(whal_Uart_Init(&dev), WHAL_EINVAL);
+    WHAL_ASSERT_EQ(whal_Uart_Init(&dev), WHAL_ENOTIMPL);
 }
 
 static void Test_Uart_NullAsyncVtable(void)
 {
     whal_Uart dev = { .driver = &mockUartDriver };
     uint8_t buf[1] = {0};
-    WHAL_ASSERT_EQ(whal_Uart_SendAsync(&dev, buf, 1), WHAL_EINVAL);
-    WHAL_ASSERT_EQ(whal_Uart_RecvAsync(&dev, buf, 1), WHAL_EINVAL);
+    WHAL_ASSERT_EQ(whal_Uart_SendAsync(&dev, buf, 1), WHAL_ENOTIMPL);
+    WHAL_ASSERT_EQ(whal_Uart_RecvAsync(&dev, buf, 1), WHAL_ENOTIMPL);
 }
 
 static void Test_Uart_ValidDispatch(void)
@@ -211,7 +211,7 @@ static void Test_Flash_NullDev(void)
 static void Test_Flash_NullDriver(void)
 {
     whal_Flash dev = { .driver = NULL };
-    WHAL_ASSERT_EQ(whal_Flash_Init(&dev), WHAL_EINVAL);
+    WHAL_ASSERT_EQ(whal_Flash_Init(&dev), WHAL_ENOTIMPL);
 }
 
 static void Test_Flash_ValidDispatch(void)
@@ -239,7 +239,7 @@ static void Test_Timer_NullDev(void)
 static void Test_Timer_NullDriver(void)
 {
     whal_Timer dev = { .driver = NULL };
-    WHAL_ASSERT_EQ(whal_Timer_Init(&dev), WHAL_EINVAL);
+    WHAL_ASSERT_EQ(whal_Timer_Init(&dev), WHAL_ENOTIMPL);
 }
 
 static void Test_Timer_ValidDispatch(void)
@@ -264,7 +264,7 @@ static void Test_Rng_NullDev(void)
 static void Test_Rng_NullDriver(void)
 {
     whal_Rng dev = { .driver = NULL };
-    WHAL_ASSERT_EQ(whal_Rng_Init(&dev), WHAL_EINVAL);
+    WHAL_ASSERT_EQ(whal_Rng_Init(&dev), WHAL_ENOTIMPL);
 }
 
 static void Test_Rng_ValidDispatch(void)
@@ -306,7 +306,7 @@ static void Test_Spi_NullDev(void)
 static void Test_Spi_NullDriver(void)
 {
     whal_Spi dev = { .driver = NULL };
-    WHAL_ASSERT_EQ(whal_Spi_Init(&dev), WHAL_EINVAL);
+    WHAL_ASSERT_EQ(whal_Spi_Init(&dev), WHAL_ENOTIMPL);
 }
 
 static void Test_Spi_ValidDispatch(void)
@@ -350,7 +350,7 @@ static void Test_Block_NullDev(void)
 static void Test_Block_NullDriver(void)
 {
     whal_Block dev = { .driver = NULL };
-    WHAL_ASSERT_EQ(whal_Block_Init(&dev), WHAL_EINVAL);
+    WHAL_ASSERT_EQ(whal_Block_Init(&dev), WHAL_ENOTIMPL);
 }
 
 static void Test_Block_ValidDispatch(void)
diff --git a/wolfHAL/block/block.h b/wolfHAL/block/block.h
index 75fb377..7df170f 100644
--- a/wolfHAL/block/block.h
+++ b/wolfHAL/block/block.h
@@ -48,7 +48,8 @@ struct whal_Block {
  * @param blockDev Block device instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 #ifdef WHAL_CFG_DIRECT_CALLBACKS
 #define whal_Block_Init(blockDev) ((blockDev)->driver->Init((blockDev)))
@@ -63,7 +64,8 @@ struct whal_Block {
  * @param blockDev Block device instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Block_Init(whal_Block *blockDev);
 /*
@@ -72,7 +74,8 @@ whal_Error whal_Block_Init(whal_Block *blockDev);
  * @param blockDev Block device instance to deinitialize.
  *
  * @retval WHAL_SUCCESS Driver-specific deinit completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Block_Deinit(whal_Block *blockDev);
 /*
@@ -84,7 +87,8 @@ whal_Error whal_Block_Deinit(whal_Block *blockDev);
  * @param blockCount Number of blocks to read.
  *
  * @retval WHAL_SUCCESS Read completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Block_Read(whal_Block *blockDev, uint32_t block, void *data,
                            uint32_t blockCount);
@@ -97,7 +101,8 @@ whal_Error whal_Block_Read(whal_Block *blockDev, uint32_t block, void *data,
  * @param blockCount Number of blocks to write.
  *
  * @retval WHAL_SUCCESS Write accepted or completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Block_Write(whal_Block *blockDev, uint32_t block,
                             const void *data, uint32_t blockCount);
@@ -109,7 +114,8 @@ whal_Error whal_Block_Write(whal_Block *blockDev, uint32_t block,
  * @param blockCount Number of blocks to erase.
  *
  * @retval WHAL_SUCCESS Erase accepted or completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Block_Erase(whal_Block *blockDev, uint32_t block,
                             uint32_t blockCount);
diff --git a/wolfHAL/block/sdhc_spi_block.h b/wolfHAL/block/sdhc_spi_block.h
index 3ab4bd2..737abf1 100644
--- a/wolfHAL/block/sdhc_spi_block.h
+++ b/wolfHAL/block/sdhc_spi_block.h
@@ -32,6 +32,7 @@ typedef struct whal_SdhcSpi_Cfg {
     whal_Timeout *timeout;
 } whal_SdhcSpi_Cfg;
 
+#ifndef WHAL_CFG_BLOCK_API_MAPPING_SDHC_SPI
 extern const whal_BlockDriver whal_SdhcSpi_Driver;
 
 whal_Error whal_SdhcSpi_Init(whal_Block *blockDev);
@@ -42,5 +43,6 @@ whal_Error whal_SdhcSpi_Write(whal_Block *blockDev, uint32_t block,
                                const void *data, uint32_t blockCount);
 whal_Error whal_SdhcSpi_Erase(whal_Block *blockDev, uint32_t block,
                                uint32_t blockCount);
+#endif /* !WHAL_CFG_BLOCK_API_MAPPING_SDHC_SPI */
 
 #endif /* WHAL_SDHC_SPI_H */
diff --git a/wolfHAL/clock/clock.h b/wolfHAL/clock/clock.h
index fa686cc..64fb957 100644
--- a/wolfHAL/clock/clock.h
+++ b/wolfHAL/clock/clock.h
@@ -40,8 +40,9 @@ struct whal_Clock {
  *
  * @param clkDev Pointer to the clock instance to bring up.
  *
- * @retval WHAL_SUCCESS Driver-specific init routine ran successfully.
- * @retval WHAL_EINVAL  Null pointer or driver rejected the configuration.
+ * @retval WHAL_SUCCESS  Driver-specific init routine ran successfully.
+ * @retval WHAL_EINVAL   Null pointer or driver rejected the configuration.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 #ifdef WHAL_CFG_DIRECT_CALLBACKS
 #define whal_Clock_Init(clkDev) ((clkDev)->driver->Init((clkDev)))
@@ -54,8 +55,9 @@ struct whal_Clock {
  *
  * @param clkDev Pointer to the clock instance to bring up.
  *
- * @retval WHAL_SUCCESS Driver-specific init routine ran successfully.
- * @retval WHAL_EINVAL  Null pointer or driver rejected the configuration.
+ * @retval WHAL_SUCCESS  Driver-specific init routine ran successfully.
+ * @retval WHAL_EINVAL   Null pointer or driver rejected the configuration.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Clock_Init(whal_Clock *clkDev);
 /*
@@ -63,8 +65,9 @@ whal_Error whal_Clock_Init(whal_Clock *clkDev);
  *
  * @param clkDev Pointer to the clock instance to tear down.
  *
- * @retval WHAL_SUCCESS Driver-specific deinit routine ran successfully.
- * @retval WHAL_EINVAL  Null pointer or driver refused to deinitialize.
+ * @retval WHAL_SUCCESS  Driver-specific deinit routine ran successfully.
+ * @retval WHAL_EINVAL   Null pointer or driver refused to deinitialize.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Clock_Deinit(whal_Clock *clkDev);
 /*
@@ -72,8 +75,9 @@ whal_Error whal_Clock_Deinit(whal_Clock *clkDev);
  *
  * @param clkDev Pointer to the clock instance to enable.
  *
- * @retval WHAL_SUCCESS Clock was enabled (or already running).
- * @retval WHAL_EINVAL  Null pointer or driver-specific enable failed.
+ * @retval WHAL_SUCCESS  Clock was enabled (or already running).
+ * @retval WHAL_EINVAL   Null pointer or driver-specific enable failed.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Clock_Enable(whal_Clock *clkDev, const void *clk);
 /*
@@ -81,8 +85,9 @@ whal_Error whal_Clock_Enable(whal_Clock *clkDev, const void *clk);
  *
  * @param clkDev Pointer to the clock instance to disable.
  *
- * @retval WHAL_SUCCESS Clock was disabled (or already stopped).
- * @retval WHAL_EINVAL  Null pointer or driver-specific disable failed.
+ * @retval WHAL_SUCCESS  Clock was disabled (or already stopped).
+ * @retval WHAL_EINVAL   Null pointer or driver-specific disable failed.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Clock_Disable(whal_Clock *clkDev, const void *clk);
 #endif
diff --git a/wolfHAL/clock/pic32cz_clock.h b/wolfHAL/clock/pic32cz_clock.h
index 59dbb99..25ec7f4 100644
--- a/wolfHAL/clock/pic32cz_clock.h
+++ b/wolfHAL/clock/pic32cz_clock.h
@@ -205,6 +205,7 @@ typedef struct whal_Pic32czClock_Clk {
     size_t mclkEnablePos;     /* Bit position within the MCLK mask register */
 } whal_Pic32czClock_Clk;
 
+#ifndef WHAL_CFG_CLOCK_API_MAPPING_PIC32CZ_PLL
 /*
  * @brief Driver instance for PIC32CZ oscillator clock.
  */
@@ -248,5 +249,6 @@ whal_Error whal_Pic32czClock_Enable(whal_Clock *clkDev, const void *clk);
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Pic32czClock_Disable(whal_Clock *clkDev, const void *clk);
+#endif /* !WHAL_CFG_CLOCK_API_MAPPING_PIC32CZ_PLL */
 
 #endif /* WHAL_PIC32CZ_CLOCK_H */
diff --git a/wolfHAL/clock/stm32c0_rcc.h b/wolfHAL/clock/stm32c0_rcc.h
index b3047f1..5acd622 100644
--- a/wolfHAL/clock/stm32c0_rcc.h
+++ b/wolfHAL/clock/stm32c0_rcc.h
@@ -60,6 +60,7 @@ typedef struct whal_Stm32c0Rcc_Cfg {
     whal_Stm32c0Rcc_HsiDiv hsidiv; /* HSI divider for HSISYS frequency */
 } whal_Stm32c0Rcc_Cfg;
 
+#ifndef WHAL_CFG_CLOCK_API_MAPPING_STM32C0
 /*
  * @brief Driver instance for the STM32C0 RCC clock controller.
  */
@@ -110,5 +111,6 @@ whal_Error whal_Stm32c0Rcc_Enable(whal_Clock *clkDev, const void *clk);
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Stm32c0Rcc_Disable(whal_Clock *clkDev, const void *clk);
+#endif /* !WHAL_CFG_CLOCK_API_MAPPING_STM32C0 */
 
 #endif /* WHAL_STM32C0_RCC_H */
diff --git a/wolfHAL/clock/stm32f4_rcc.h b/wolfHAL/clock/stm32f4_rcc.h
index f7f92c5..c4449d7 100644
--- a/wolfHAL/clock/stm32f4_rcc.h
+++ b/wolfHAL/clock/stm32f4_rcc.h
@@ -94,6 +94,7 @@ typedef struct whal_Stm32f4Rcc_Cfg {
     uint8_t ppre2; /* APB2 prescaler (0=/1, 4=/2, 5=/4, 6=/8, 7=/16) */
 } whal_Stm32f4Rcc_Cfg;
 
+#ifndef WHAL_CFG_CLOCK_API_MAPPING_STM32F4_PLL
 /*
  * @brief Driver instance for the STM32F4 RCC PLL clock controller.
  */
@@ -145,5 +146,6 @@ whal_Error whal_Stm32f4Rcc_Enable(whal_Clock *clkDev, const void *clk);
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Stm32f4Rcc_Disable(whal_Clock *clkDev, const void *clk);
+#endif /* !WHAL_CFG_CLOCK_API_MAPPING_STM32F4_PLL */
 
 #endif /* WHAL_STM32F4_RCC_H */
diff --git a/wolfHAL/clock/stm32h5_rcc.h b/wolfHAL/clock/stm32h5_rcc.h
index e7aa8f7..910bd30 100644
--- a/wolfHAL/clock/stm32h5_rcc.h
+++ b/wolfHAL/clock/stm32h5_rcc.h
@@ -104,6 +104,7 @@ typedef struct whal_Stm32h5Rcc_Cfg {
     void *sysClkCfg; /* Pointer to PllClkCfg or HsiClkCfg based on driver */
 } whal_Stm32h5Rcc_Cfg;
 
+#if !defined(WHAL_CFG_CLOCK_API_MAPPING_STM32H5_PLL) && !defined(WHAL_CFG_CLOCK_API_MAPPING_STM32H5_HSI)
 /*
  * @brief Driver instance for PLL1 clock source.
  */
@@ -184,6 +185,7 @@ whal_Error whal_Stm32h5Rcc_Enable(whal_Clock *clkDev, const void *clk);
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Stm32h5Rcc_Disable(whal_Clock *clkDev, const void *clk);
+#endif /* !WHAL_CFG_CLOCK_API_MAPPING_STM32H5_PLL && !WHAL_CFG_CLOCK_API_MAPPING_STM32H5_HSI */
 
 /*
  * @brief Enable or disable the HSI48 oscillator.
diff --git a/wolfHAL/clock/stm32wb_rcc.h b/wolfHAL/clock/stm32wb_rcc.h
index 8d563b5..b097edf 100644
--- a/wolfHAL/clock/stm32wb_rcc.h
+++ b/wolfHAL/clock/stm32wb_rcc.h
@@ -126,6 +126,7 @@ typedef struct whal_Stm32wbRcc_Cfg {
     void *sysClkCfg; /* Pointer to PllClkCfg or MsiClkCfg based on driver */
 } whal_Stm32wbRcc_Cfg;
 
+#if !defined(WHAL_CFG_CLOCK_API_MAPPING_STM32WB_PLL) && !defined(WHAL_CFG_CLOCK_API_MAPPING_STM32WB_MSI)
 /*
  * @brief Driver instance for the STM32 RCC clock controller.
  */
@@ -188,6 +189,7 @@ whal_Error whal_Stm32wbRcc_Enable(whal_Clock *clkDev, const void *clk);
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Stm32wbRcc_Disable(whal_Clock *clkDev, const void *clk);
+#endif /* !WHAL_CFG_CLOCK_API_MAPPING_STM32WB_PLL && !WHAL_CFG_CLOCK_API_MAPPING_STM32WB_MSI */
 /*
  * @brief Enable or disable the HSI48 oscillator required by the RNG peripheral.
  *
diff --git a/wolfHAL/crypto/stm32wb_aes.h b/wolfHAL/crypto/stm32wb_aes.h
index faeab83..c781e29 100644
--- a/wolfHAL/crypto/stm32wb_aes.h
+++ b/wolfHAL/crypto/stm32wb_aes.h
@@ -21,6 +21,7 @@ typedef struct {
     whal_Timeout *timeout;
 } whal_Stm32wbAes_Cfg;
 
+#ifndef WHAL_CFG_CRYPTO_API_MAPPING_STM32WB_AES
 /*
  * @brief Driver instance for STM32WB AES peripheral.
  */
@@ -45,6 +46,7 @@ whal_Error whal_Stm32wbAes_Init(whal_Crypto *cryptoDev);
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Stm32wbAes_Deinit(whal_Crypto *cryptoDev);
+#endif /* !WHAL_CFG_CRYPTO_API_MAPPING_STM32WB_AES */
 
 
 /*
diff --git a/wolfHAL/dma/stm32wb_dma.h b/wolfHAL/dma/stm32wb_dma.h
index 11e6188..70ae230 100644
--- a/wolfHAL/dma/stm32wb_dma.h
+++ b/wolfHAL/dma/stm32wb_dma.h
@@ -76,11 +76,39 @@ typedef struct {
     uint8_t numChannels;     /* Number of channels (7 for DMA1, 5 for DMA2) */
 } whal_Stm32wbDma_Cfg;
 
+#ifndef WHAL_CFG_DMA_API_MAPPING_STM32WB
 /*
  * @brief Driver instance for STM32WB DMA.
  */
 extern const whal_DmaDriver whal_Stm32wbDma_Driver;
 
+/*
+ * @brief Initialize the STM32WB DMA controller.
+ */
+whal_Error whal_Stm32wbDma_Init(whal_Dma *dmaDev);
+
+/*
+ * @brief Deinitialize the STM32WB DMA controller.
+ */
+whal_Error whal_Stm32wbDma_Deinit(whal_Dma *dmaDev);
+
+/*
+ * @brief Configure a DMA channel with platform-specific settings.
+ */
+whal_Error whal_Stm32wbDma_Configure(whal_Dma *dmaDev, size_t ch,
+                                     const void *chCfg);
+
+/*
+ * @brief Start a previously configured DMA channel.
+ */
+whal_Error whal_Stm32wbDma_Start(whal_Dma *dmaDev, size_t ch);
+
+/*
+ * @brief Stop a DMA channel.
+ */
+whal_Error whal_Stm32wbDma_Stop(whal_Dma *dmaDev, size_t ch);
+#endif /* !WHAL_CFG_DMA_API_MAPPING_STM32WB */
+
 /*
  * @brief DMA callback type.
  *
diff --git a/wolfHAL/error.h b/wolfHAL/error.h
index 5e8e03a..388a069 100644
--- a/wolfHAL/error.h
+++ b/wolfHAL/error.h
@@ -13,7 +13,7 @@ typedef int whal_Error;
 enum {
     /* Operation completed successfully. */
     WHAL_SUCCESS = 0,
-    /* Invalid argument or unsupported operation. */
+    /* Invalid argument (null pointer, bad configuration). */
     WHAL_EINVAL = -4000,
     /* Resource not ready or busy. */
     WHAL_ENOTREADY = -4001,
@@ -21,6 +21,8 @@ enum {
     WHAL_EHARDWARE = -4002,
     /* Operation timed out. */
     WHAL_ETIMEOUT = -4003,
+    /* Operation not implemented by the selected driver. */
+    WHAL_ENOTIMPL = -4004,
 };
 
 #endif /* WHAL_ERROR_H */
diff --git a/wolfHAL/eth/stm32h5_eth.h b/wolfHAL/eth/stm32h5_eth.h
index 11e1cf4..01c5642 100644
--- a/wolfHAL/eth/stm32h5_eth.h
+++ b/wolfHAL/eth/stm32h5_eth.h
@@ -46,6 +46,7 @@ typedef struct whal_Stm32h5Eth_Cfg {
     size_t rxHead;                        /* Next RX descriptor to check */
 } whal_Stm32h5Eth_Cfg;
 
+#ifndef WHAL_CFG_ETH_API_MAPPING_STM32H5
 /*
  * @brief Driver instance for STM32H5 Ethernet MAC.
  */
@@ -163,6 +164,7 @@ whal_Error whal_Stm32h5Eth_MdioRead(whal_Eth *ethDev, uint8_t phyAddr,
  */
 whal_Error whal_Stm32h5Eth_MdioWrite(whal_Eth *ethDev, uint8_t phyAddr,
                                        uint8_t reg, uint16_t val);
+#endif /* !WHAL_CFG_ETH_API_MAPPING_STM32H5 */
 
 /*
  * @brief Enable or disable MAC-internal loopback.
diff --git a/wolfHAL/eth_phy/lan8742a_eth_phy.h b/wolfHAL/eth_phy/lan8742a_eth_phy.h
index fb054a7..e008756 100644
--- a/wolfHAL/eth_phy/lan8742a_eth_phy.h
+++ b/wolfHAL/eth_phy/lan8742a_eth_phy.h
@@ -20,6 +20,7 @@ typedef struct whal_Lan8742a_Cfg {
     whal_Timeout *timeout;
 } whal_Lan8742a_Cfg;
 
+#ifndef WHAL_CFG_ETH_PHY_API_MAPPING_LAN8742A
 /*
  * @brief Driver instance for LAN8742A PHY.
  */
@@ -62,5 +63,6 @@ whal_Error whal_Lan8742a_Deinit(whal_EthPhy *phyDev);
  */
 whal_Error whal_Lan8742a_GetLinkState(whal_EthPhy *phyDev, uint8_t *up,
                                        uint8_t *speed, uint8_t *duplex);
+#endif /* !WHAL_CFG_ETH_PHY_API_MAPPING_LAN8742A */
 
 #endif /* WHAL_LAN8742A_H */
diff --git a/wolfHAL/flash/flash.h b/wolfHAL/flash/flash.h
index d8fc702..9101540 100644
--- a/wolfHAL/flash/flash.h
+++ b/wolfHAL/flash/flash.h
@@ -48,7 +48,8 @@ struct whal_Flash {
  * @param flashDev Flash instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 #ifdef WHAL_CFG_DIRECT_CALLBACKS
 #define whal_Flash_Init(flashDev) ((flashDev)->driver->Init((flashDev)))
@@ -65,7 +66,8 @@ struct whal_Flash {
  * @param flashDev Flash instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Flash_Init(whal_Flash *flashDev);
 /*
@@ -74,7 +76,8 @@ whal_Error whal_Flash_Init(whal_Flash *flashDev);
  * @param flashDev Flash instance to deinitialize.
  *
  * @retval WHAL_SUCCESS Driver-specific deinit completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Flash_Deinit(whal_Flash *flashDev);
 /*
@@ -85,7 +88,8 @@ whal_Error whal_Flash_Deinit(whal_Flash *flashDev);
  * @param len      Number of bytes to lock.
  *
  * @retval WHAL_SUCCESS Lock applied.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Flash_Lock(whal_Flash *flashDev, size_t addr, size_t len);
 /*
@@ -96,7 +100,8 @@ whal_Error whal_Flash_Lock(whal_Flash *flashDev, size_t addr, size_t len);
  * @param len      Number of bytes to unlock.
  *
  * @retval WHAL_SUCCESS Unlock applied.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Flash_Unlock(whal_Flash *flashDev, size_t addr, size_t len);
 /*
@@ -108,7 +113,8 @@ whal_Error whal_Flash_Unlock(whal_Flash *flashDev, size_t addr, size_t len);
  * @param dataSz   Number of bytes to read.
  *
  * @retval WHAL_SUCCESS Read completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Flash_Read(whal_Flash *flashDev, size_t addr, void *data, size_t dataSz);
 /*
@@ -120,7 +126,8 @@ whal_Error whal_Flash_Read(whal_Flash *flashDev, size_t addr, void *data, size_t
  * @param dataSz   Number of bytes to write.
  *
  * @retval WHAL_SUCCESS Write accepted or completed.
- * @retval WHAL_EINVAL  Null pointer, missing driver function, or bad arguments.
+ * @retval WHAL_EINVAL   Null pointer or bad arguments.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Flash_Write(whal_Flash *flashDev, size_t addr, const void *data, size_t dataSz);
 /*
@@ -131,7 +138,8 @@ whal_Error whal_Flash_Write(whal_Flash *flashDev, size_t addr, const void *data,
  * @param dataSz   Number of bytes (or sector-aligned size) to erase.
  *
  * @retval WHAL_SUCCESS Erase accepted or completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Flash_Erase(whal_Flash *flashDev, size_t addr, size_t dataSz);
 #endif
diff --git a/wolfHAL/flash/pic32cz_flash.h b/wolfHAL/flash/pic32cz_flash.h
index da01fcb..fa0f778 100644
--- a/wolfHAL/flash/pic32cz_flash.h
+++ b/wolfHAL/flash/pic32cz_flash.h
@@ -32,6 +32,7 @@ typedef struct whal_Pic32czFlash_Cfg {
     whal_Timeout *timeout;
 } whal_Pic32czFlash_Cfg;
 
+#ifndef WHAL_CFG_FLASH_API_MAPPING_PIC32CZ
 /*
  * @brief Driver instance for PIC32CZ flash.
  */
@@ -120,5 +121,6 @@ whal_Error whal_Pic32czFlash_Write(whal_Flash *flashDev, size_t addr, const void
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Pic32czFlash_Erase(whal_Flash *flashDev, size_t addr, size_t dataSz);
+#endif /* !WHAL_CFG_FLASH_API_MAPPING_PIC32CZ */
 
 #endif /* WHAL_PIC32CZ_FLASH_H */
diff --git a/wolfHAL/flash/spi_nor_flash.h b/wolfHAL/flash/spi_nor_flash.h
index d108f64..2006c64 100644
--- a/wolfHAL/flash/spi_nor_flash.h
+++ b/wolfHAL/flash/spi_nor_flash.h
@@ -53,10 +53,6 @@ typedef struct whal_SpiNor_Cfg {
  */
 extern const whal_FlashDriver whal_SpiNor_Driver;
 
-/* -------------------------------------------------------------------- */
-/*  Init / Deinit                                                       */
-/* -------------------------------------------------------------------- */
-
 /*
  * @brief Initialize a SPI-NOR device in 3-byte address mode.
  *
@@ -72,22 +68,6 @@ extern const whal_FlashDriver whal_SpiNor_Driver;
  */
 whal_Error whal_SpiNor_Init(whal_Flash *flashDev);
 
-/*
- * @brief Initialize a SPI-NOR device and enter 4-byte address mode.
- *
- * Performs standard initialization via whal_SpiNor_Init(), then sends the
- * Enter 4-Byte Address Mode command (0xB7). After this call, all 4bMode
- * variant functions can be used. The device remains in 4-byte mode until
- * power cycle or an explicit exit command.
- *
- * @param flashDev Flash device instance.
- *
- * @retval WHAL_SUCCESS    Device initialized and 4-byte mode command sent.
- * @retval WHAL_EINVAL     Null pointer or invalid configuration.
- * @retval WHAL_EHARDWARE  No device detected.
- */
-whal_Error whal_SpiNor4bMode_Init(whal_Flash *flashDev);
-
 /*
  * @brief Deinitialize a SPI-NOR device.
  *
@@ -100,10 +80,6 @@ whal_Error whal_SpiNor4bMode_Init(whal_Flash *flashDev);
  */
 whal_Error whal_SpiNor_Deinit(whal_Flash *flashDev);
 
-/* -------------------------------------------------------------------- */
-/*  Lock / Unlock                                                       */
-/* -------------------------------------------------------------------- */
-
 /*
  * @brief Lock the entire device by setting all block protect bits.
  *
@@ -136,6 +112,26 @@ whal_Error whal_SpiNor_Lock(whal_Flash *flashDev, size_t addr, size_t len);
  */
 whal_Error whal_SpiNor_Unlock(whal_Flash *flashDev, size_t addr, size_t len);
 
+/* -------------------------------------------------------------------- */
+/*  Init / Deinit — 4-byte address mode                                 */
+/* -------------------------------------------------------------------- */
+
+/*
+ * @brief Initialize a SPI-NOR device and enter 4-byte address mode.
+ *
+ * Performs standard initialization via whal_SpiNor_Init(), then sends the
+ * Enter 4-Byte Address Mode command (0xB7). After this call, all 4bMode
+ * variant functions can be used. The device remains in 4-byte mode until
+ * power cycle or an explicit exit command.
+ *
+ * @param flashDev Flash device instance.
+ *
+ * @retval WHAL_SUCCESS    Device initialized and 4-byte mode command sent.
+ * @retval WHAL_EINVAL     Null pointer or invalid configuration.
+ * @retval WHAL_EHARDWARE  No device detected.
+ */
+whal_Error whal_SpiNor4bMode_Init(whal_Flash *flashDev);
+
 /* -------------------------------------------------------------------- */
 /*  Read — 3-byte address                                               */
 /* -------------------------------------------------------------------- */
diff --git a/wolfHAL/flash/stm32c0_flash.h b/wolfHAL/flash/stm32c0_flash.h
index 7663245..ee08654 100644
--- a/wolfHAL/flash/stm32c0_flash.h
+++ b/wolfHAL/flash/stm32c0_flash.h
@@ -40,6 +40,7 @@ typedef enum whal_Stm32c0Flash_Latency {
     WHAL_STM32C0_FLASH_LATENCY_1, /* 1 wait state */
 } whal_Stm32c0Flash_Latency;
 
+#ifndef WHAL_CFG_FLASH_API_MAPPING_STM32C0
 /*
  * @brief Driver instance for STM32C0 flash.
  */
@@ -132,6 +133,7 @@ whal_Error whal_Stm32c0Flash_Write(whal_Flash *flashDev, size_t addr, const void
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Stm32c0Flash_Erase(whal_Flash *flashDev, size_t addr, size_t dataSz);
+#endif /* !WHAL_CFG_FLASH_API_MAPPING_STM32C0 */
 
 /*
  * @brief Update flash latency wait states.
diff --git a/wolfHAL/flash/stm32f4_flash.h b/wolfHAL/flash/stm32f4_flash.h
index 83bc9f8..1980ef0 100644
--- a/wolfHAL/flash/stm32f4_flash.h
+++ b/wolfHAL/flash/stm32f4_flash.h
@@ -61,6 +61,7 @@ typedef enum whal_Stm32f4Flash_Latency {
     WHAL_STM32F4_FLASH_LATENCY_3, /* 3 wait states */
 } whal_Stm32f4Flash_Latency;
 
+#ifndef WHAL_CFG_FLASH_API_MAPPING_STM32F4
 /*
  * @brief Driver instance for STM32F4 flash.
  */
@@ -158,6 +159,7 @@ whal_Error whal_Stm32f4Flash_Write(whal_Flash *flashDev, size_t addr,
  */
 whal_Error whal_Stm32f4Flash_Erase(whal_Flash *flashDev, size_t addr,
                                     size_t dataSz);
+#endif /* !WHAL_CFG_FLASH_API_MAPPING_STM32F4 */
 
 /*
  * @brief Update flash latency wait states.
diff --git a/wolfHAL/flash/stm32h5_flash.h b/wolfHAL/flash/stm32h5_flash.h
index 4631e3b..6289fb3 100644
--- a/wolfHAL/flash/stm32h5_flash.h
+++ b/wolfHAL/flash/stm32h5_flash.h
@@ -24,6 +24,7 @@ typedef struct whal_Stm32h5Flash_Cfg {
     whal_Timeout *timeout;
 } whal_Stm32h5Flash_Cfg;
 
+#ifndef WHAL_CFG_FLASH_API_MAPPING_STM32H5
 /*
  * @brief Driver instance for STM32H5 flash.
  */
@@ -121,6 +122,7 @@ whal_Error whal_Stm32h5Flash_Write(whal_Flash *flashDev, size_t addr,
  */
 whal_Error whal_Stm32h5Flash_Erase(whal_Flash *flashDev, size_t addr,
                                     size_t dataSz);
+#endif /* !WHAL_CFG_FLASH_API_MAPPING_STM32H5 */
 
 /*
  * @brief Set flash access latency (wait states) and write high-frequency mode.
diff --git a/wolfHAL/flash/stm32wb_flash.h b/wolfHAL/flash/stm32wb_flash.h
index 56fb5ad..afb84fc 100644
--- a/wolfHAL/flash/stm32wb_flash.h
+++ b/wolfHAL/flash/stm32wb_flash.h
@@ -48,6 +48,7 @@ typedef enum whal_Stm32wbFlash_Latency {
     WHAL_STM32WB_FLASH_LATENCY_3, /* 3 wait states */
 } whal_Stm32wbFlash_Latency;
 
+#ifndef WHAL_CFG_FLASH_API_MAPPING_STM32WB
 /*
  * @brief Driver instance for STM32 flash.
  */
@@ -130,6 +131,7 @@ whal_Error whal_Stm32wbFlash_Write(whal_Flash *flashDev, size_t addr, const void
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Stm32wbFlash_Erase(whal_Flash *flashDev, size_t addr, size_t dataSz);
+#endif /* !WHAL_CFG_FLASH_API_MAPPING_STM32WB */
 /*
  * @brief Update flash latency wait states.
  *
diff --git a/wolfHAL/gpio/gpio.h b/wolfHAL/gpio/gpio.h
index 8f89b6a..2b65c7f 100644
--- a/wolfHAL/gpio/gpio.h
+++ b/wolfHAL/gpio/gpio.h
@@ -41,7 +41,8 @@ struct whal_Gpio {
  * @param gpioDev GPIO instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 #ifdef WHAL_CFG_DIRECT_CALLBACKS
 #define whal_Gpio_Init(gpioDev) ((gpioDev)->driver->Init((gpioDev)))
@@ -55,7 +56,8 @@ struct whal_Gpio {
  * @param gpioDev GPIO instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Gpio_Init(whal_Gpio *gpioDev);
 /*
@@ -64,7 +66,8 @@ whal_Error whal_Gpio_Init(whal_Gpio *gpioDev);
  * @param gpioDev GPIO instance to deinitialize.
  *
  * @retval WHAL_SUCCESS Driver-specific deinit completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Gpio_Deinit(whal_Gpio *gpioDev);
 /*
@@ -75,7 +78,8 @@ whal_Error whal_Gpio_Deinit(whal_Gpio *gpioDev);
  * @param value   Storage for the sampled pin value.
  *
  * @retval WHAL_SUCCESS Pin value stored in @p value.
- * @retval WHAL_EINVAL  Null pointer, missing driver function, or bad pin.
+ * @retval WHAL_EINVAL   Null pointer or bad pin.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Gpio_Get(whal_Gpio *gpioDev, size_t pin, size_t *value);
 /*
@@ -86,7 +90,8 @@ whal_Error whal_Gpio_Get(whal_Gpio *gpioDev, size_t pin, size_t *value);
  * @param value   Output value to drive (typically 0 or 1).
  *
  * @retval WHAL_SUCCESS Pin updated.
- * @retval WHAL_EINVAL  Null pointer, missing driver function, or bad pin.
+ * @retval WHAL_EINVAL   Null pointer or bad pin.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Gpio_Set(whal_Gpio *gpioDev, size_t pin, size_t value);
 #endif
diff --git a/wolfHAL/gpio/pic32cz_gpio.h b/wolfHAL/gpio/pic32cz_gpio.h
index 9b9956e..0d9e9c3 100644
--- a/wolfHAL/gpio/pic32cz_gpio.h
+++ b/wolfHAL/gpio/pic32cz_gpio.h
@@ -89,6 +89,7 @@ typedef struct whal_Pic32czGpio_Cfg {
     whal_Pic32czGpio_PinCfg *pinCfg; /* Array of pin configurations */
 } whal_Pic32czGpio_Cfg;
 
+#ifndef WHAL_CFG_GPIO_API_MAPPING_PIC32CZ
 /*
  * @brief Driver instance for PIC32CZ GPIO.
  */
@@ -134,5 +135,6 @@ whal_Error whal_Pic32czGpio_Get(whal_Gpio *gpioDev, size_t pin, size_t *value);
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Pic32czGpio_Set(whal_Gpio *gpioDev, size_t pin, size_t value);
+#endif /* !WHAL_CFG_GPIO_API_MAPPING_PIC32CZ */
 
 #endif /* WHAL_PIC32CZ_GPIO_H */
diff --git a/wolfHAL/gpio/stm32c0_gpio.h b/wolfHAL/gpio/stm32c0_gpio.h
index b263761..729c67a 100644
--- a/wolfHAL/gpio/stm32c0_gpio.h
+++ b/wolfHAL/gpio/stm32c0_gpio.h
@@ -15,11 +15,13 @@
 typedef whal_Stm32wbGpio_Cfg    whal_Stm32c0Gpio_Cfg;
 typedef whal_Stm32wbGpio_PinCfg whal_Stm32c0Gpio_PinCfg;
 
+#ifndef WHAL_CFG_GPIO_API_MAPPING_STM32C0
 #define whal_Stm32c0Gpio_Driver whal_Stm32wbGpio_Driver
 #define whal_Stm32c0Gpio_Init   whal_Stm32wbGpio_Init
 #define whal_Stm32c0Gpio_Deinit whal_Stm32wbGpio_Deinit
 #define whal_Stm32c0Gpio_Get    whal_Stm32wbGpio_Get
 #define whal_Stm32c0Gpio_Set    whal_Stm32wbGpio_Set
+#endif /* !WHAL_CFG_GPIO_API_MAPPING_STM32C0 */
 
 /*
  * @brief GPIO mode selection (re-exported from STM32WB).
diff --git a/wolfHAL/gpio/stm32f4_gpio.h b/wolfHAL/gpio/stm32f4_gpio.h
index 79c0905..d8ac28b 100644
--- a/wolfHAL/gpio/stm32f4_gpio.h
+++ b/wolfHAL/gpio/stm32f4_gpio.h
@@ -15,11 +15,13 @@
 typedef whal_Stm32wbGpio_Cfg    whal_Stm32f4Gpio_Cfg;
 typedef whal_Stm32wbGpio_PinCfg whal_Stm32f4Gpio_PinCfg;
 
+#ifndef WHAL_CFG_GPIO_API_MAPPING_STM32F4
 #define whal_Stm32f4Gpio_Driver whal_Stm32wbGpio_Driver
 #define whal_Stm32f4Gpio_Init   whal_Stm32wbGpio_Init
 #define whal_Stm32f4Gpio_Deinit whal_Stm32wbGpio_Deinit
 #define whal_Stm32f4Gpio_Get    whal_Stm32wbGpio_Get
 #define whal_Stm32f4Gpio_Set    whal_Stm32wbGpio_Set
+#endif /* !WHAL_CFG_GPIO_API_MAPPING_STM32F4 */
 
 /*
  * @brief GPIO mode selection (re-exported from STM32WB).
diff --git a/wolfHAL/gpio/stm32h5_gpio.h b/wolfHAL/gpio/stm32h5_gpio.h
index 56c8a0d..7be8b80 100644
--- a/wolfHAL/gpio/stm32h5_gpio.h
+++ b/wolfHAL/gpio/stm32h5_gpio.h
@@ -15,11 +15,13 @@
 typedef whal_Stm32wbGpio_Cfg    whal_Stm32h5Gpio_Cfg;
 typedef whal_Stm32wbGpio_PinCfg whal_Stm32h5Gpio_PinCfg;
 
+#ifndef WHAL_CFG_GPIO_API_MAPPING_STM32H5
 #define whal_Stm32h5Gpio_Driver whal_Stm32wbGpio_Driver
 #define whal_Stm32h5Gpio_Init   whal_Stm32wbGpio_Init
 #define whal_Stm32h5Gpio_Deinit whal_Stm32wbGpio_Deinit
 #define whal_Stm32h5Gpio_Get    whal_Stm32wbGpio_Get
 #define whal_Stm32h5Gpio_Set    whal_Stm32wbGpio_Set
+#endif /* !WHAL_CFG_GPIO_API_MAPPING_STM32H5 */
 
 /*
  * @brief GPIO mode selection (re-exported from STM32WB).
diff --git a/wolfHAL/gpio/stm32wb_gpio.h b/wolfHAL/gpio/stm32wb_gpio.h
index f89f3fa..a3a9461 100644
--- a/wolfHAL/gpio/stm32wb_gpio.h
+++ b/wolfHAL/gpio/stm32wb_gpio.h
@@ -107,6 +107,10 @@ typedef struct {
     size_t pinCount;                  /* Number of pins to configure */
 } whal_Stm32wbGpio_Cfg;
 
+#if !defined(WHAL_CFG_GPIO_API_MAPPING_STM32WB) && \
+    !defined(WHAL_CFG_GPIO_API_MAPPING_STM32F4) && \
+    !defined(WHAL_CFG_GPIO_API_MAPPING_STM32H5) && \
+    !defined(WHAL_CFG_GPIO_API_MAPPING_STM32C0)
 /*
  * @brief Driver instance for STM32 GPIO.
  */
@@ -152,5 +156,6 @@ whal_Error whal_Stm32wbGpio_Get(whal_Gpio *gpioDev, size_t pin, size_t *value);
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Stm32wbGpio_Set(whal_Gpio *gpioDev, size_t pin, size_t value);
+#endif /* !WHAL_CFG_GPIO_API_MAPPING */
 
 #endif /* WHAL_STM32WB_GPIO_H */
diff --git a/wolfHAL/i2c/stm32wb_i2c.h b/wolfHAL/i2c/stm32wb_i2c.h
index 059144e..aefdc1a 100644
--- a/wolfHAL/i2c/stm32wb_i2c.h
+++ b/wolfHAL/i2c/stm32wb_i2c.h
@@ -27,6 +27,7 @@ typedef struct whal_Stm32wbI2c_Cfg {
     whal_Timeout *timeout;
 } whal_Stm32wbI2c_Cfg;
 
+#ifndef WHAL_CFG_I2C_API_MAPPING_STM32WB
 /*
  * @brief Driver instance for STM32WB I2C peripheral.
  */
@@ -96,5 +97,6 @@ whal_Error whal_Stm32wbI2c_EndCom(whal_I2c *i2cDev);
  */
 whal_Error whal_Stm32wbI2c_Transfer(whal_I2c *i2cDev, whal_I2c_Msg *msgs,
                                      size_t numMsgs);
+#endif /* !WHAL_CFG_I2C_API_MAPPING_STM32WB */
 
 #endif /* WHAL_STM32WB_I2C_H */
diff --git a/wolfHAL/irq/cortex_m4_nvic.h b/wolfHAL/irq/cortex_m4_nvic.h
index 43c8f80..46a5565 100644
--- a/wolfHAL/irq/cortex_m4_nvic.h
+++ b/wolfHAL/irq/cortex_m4_nvic.h
@@ -21,9 +21,16 @@ typedef struct {
     uint8_t priority;
 } whal_Nvic_Cfg;
 
+#ifndef WHAL_CFG_IRQ_API_MAPPING_NVIC
 /*
  * @brief Driver instance for Cortex-M4 NVIC.
  */
 extern const whal_IrqDriver whal_Nvic_Driver;
 
+whal_Error whal_Nvic_Init(whal_Irq *irqDev);
+whal_Error whal_Nvic_Deinit(whal_Irq *irqDev);
+whal_Error whal_Nvic_Enable(whal_Irq *irqDev, size_t irq, const void *irqCfg);
+whal_Error whal_Nvic_Disable(whal_Irq *irqDev, size_t irq);
+#endif /* !WHAL_CFG_IRQ_API_MAPPING_NVIC */
+
 #endif /* WHAL_CORTEX_M4_NVIC_H */
diff --git a/wolfHAL/platform/arm/cortex_m0plus.h b/wolfHAL/platform/arm/cortex_m0plus.h
index 802179f..f97dcb3 100644
--- a/wolfHAL/platform/arm/cortex_m0plus.h
+++ b/wolfHAL/platform/arm/cortex_m0plus.h
@@ -3,11 +3,9 @@
 
 #include <wolfHAL/timer/systick.h>
 
-#define WHAL_CORTEX_M0PLUS_SYSTICK_DEVICE  \
-    .regmap = {                            \
-        .base = 0xE000E010,                \
-        .size = 0x400,                     \
-    },                                     \
-    .driver = &whal_SysTick_Driver
+#define WHAL_CORTEX_M0PLUS_SYSTICK_REGMAP  \
+    .base = 0xE000E010,                    \
+    .size = 0x400
+#define WHAL_CORTEX_M0PLUS_SYSTICK_DRIVER &whal_SysTick_Driver
 
 #endif /* WHAL_CORTEX_M0PLUS_H */
diff --git a/wolfHAL/platform/arm/cortex_m33.h b/wolfHAL/platform/arm/cortex_m33.h
index 50c6312..9ab025a 100644
--- a/wolfHAL/platform/arm/cortex_m33.h
+++ b/wolfHAL/platform/arm/cortex_m33.h
@@ -3,11 +3,9 @@
 
 #include <wolfHAL/timer/systick.h>
 
-#define WHAL_CORTEX_M33_SYSTICK_DEVICE  \
-    .regmap = {                         \
-        .base = 0xE000E010,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_SysTick_Driver
+#define WHAL_CORTEX_M33_SYSTICK_REGMAP  \
+    .base = 0xE000E010,                 \
+    .size = 0x400
+#define WHAL_CORTEX_M33_SYSTICK_DRIVER &whal_SysTick_Driver
 
 #endif /* WHAL_CORTEX_M33_H */
diff --git a/wolfHAL/platform/arm/cortex_m4.h b/wolfHAL/platform/arm/cortex_m4.h
index e90d266..b60dd92 100644
--- a/wolfHAL/platform/arm/cortex_m4.h
+++ b/wolfHAL/platform/arm/cortex_m4.h
@@ -4,18 +4,14 @@
 #include <wolfHAL/timer/systick.h>
 #include <wolfHAL/irq/cortex_m4_nvic.h>
 
-#define WHAL_CORTEX_M4_SYSTICK_DEVICE   \
-    .regmap = {                         \
-        .base = 0xE000E010,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_SysTick_Driver
+#define WHAL_CORTEX_M4_SYSTICK_REGMAP   \
+    .base = 0xE000E010,                 \
+    .size = 0x400
+#define WHAL_CORTEX_M4_SYSTICK_DRIVER &whal_SysTick_Driver
 
-#define WHAL_CORTEX_M4_NVIC_DEVICE      \
-    .regmap = {                         \
-        .base = 0xE000E100,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Nvic_Driver
+#define WHAL_CORTEX_M4_NVIC_REGMAP      \
+    .base = 0xE000E100,                 \
+    .size = 0x400
+#define WHAL_CORTEX_M4_NVIC_DRIVER &whal_Nvic_Driver
 
 #endif /* WHAL_CORTEX_M4_H */
diff --git a/wolfHAL/platform/arm/cortex_m7.h b/wolfHAL/platform/arm/cortex_m7.h
index 4906015..5583100 100644
--- a/wolfHAL/platform/arm/cortex_m7.h
+++ b/wolfHAL/platform/arm/cortex_m7.h
@@ -3,11 +3,9 @@
 
 #include <wolfHAL/timer/systick.h>
 
-#define WHAL_CORTEX_M7_SYSTICK_DEVICE   \
-    .regmap = {                         \
-        .base = 0xE000E010,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_SysTick_Driver
+#define WHAL_CORTEX_M7_SYSTICK_REGMAP   \
+    .base = 0xE000E010,                 \
+    .size = 0x400
+#define WHAL_CORTEX_M7_SYSTICK_DRIVER &whal_SysTick_Driver
 
 #endif /* WHAL_CORTEX_M7_H */
diff --git a/wolfHAL/platform/microchip/pic32cz.h b/wolfHAL/platform/microchip/pic32cz.h
index 6cac3eb..43d2421 100644
--- a/wolfHAL/platform/microchip/pic32cz.h
+++ b/wolfHAL/platform/microchip/pic32cz.h
@@ -8,40 +8,30 @@
 #include <wolfHAL/flash/pic32cz_flash.h>
 #include <wolfHAL/platform/arm/cortex_m7.h>
 
-#define WHAL_PIC32CZ_FLASH_DEVICE       \
-    .regmap = {                         \
-        .base = 0x44002000,             \
-        .size = 0x4000,                 \
-    },                                  \
-    .driver = &whal_Pic32czFlash_Driver
-
-#define WHAL_PIC32CZ_SUPPLY_DEVICE      \
-    .regmap = {                         \
-        .base = 0x44020000,             \
-        .size = 0x2000,                 \
-    },                                  \
-    .driver = &whal_Pic32czSupc_Driver
-
-#define WHAL_PIC32CZ_CLOCK_PLL_DEVICE   \
-    .regmap = {                         \
-        .base = 0x44040000,             \
-        .size = 0x14000,                \
-    },                                  \
-    .driver = &whal_Pic32czClockPll_Driver
-
-#define WHAL_PIC32CZ_GPIO_DEVICE        \
-    .regmap = {                         \
-        .base = 0x44840000,             \
-        .size = 0x2000,                 \
-    },                                  \
-    .driver = &whal_Pic32czGpio_Driver
-
-#define WHAL_PIC32CZ_SERCOM4_UART_DEVICE    \
-    .regmap = {                             \
-        .base = 0x46004000,                 \
-        .size = 0x2000,                     \
-    },                                      \
-    .driver = &whal_Pic32czUart_Driver
+#define WHAL_PIC32CZ_FLASH_REGMAP       \
+    .base = 0x44002000,                 \
+    .size = 0x4000
+#define WHAL_PIC32CZ_FLASH_DRIVER &whal_Pic32czFlash_Driver
+
+#define WHAL_PIC32CZ_SUPPLY_REGMAP      \
+    .base = 0x44020000,                 \
+    .size = 0x2000
+#define WHAL_PIC32CZ_SUPPLY_DRIVER &whal_Pic32czSupc_Driver
+
+#define WHAL_PIC32CZ_CLOCK_PLL_REGMAP   \
+    .base = 0x44040000,                 \
+    .size = 0x14000
+#define WHAL_PIC32CZ_CLOCK_PLL_DRIVER &whal_Pic32czClockPll_Driver
+
+#define WHAL_PIC32CZ_GPIO_REGMAP        \
+    .base = 0x44840000,                 \
+    .size = 0x2000
+#define WHAL_PIC32CZ_GPIO_DRIVER &whal_Pic32czGpio_Driver
+
+#define WHAL_PIC32CZ_SERCOM4_UART_REGMAP    \
+    .base = 0x46004000,                     \
+    .size = 0x2000
+#define WHAL_PIC32CZ_SERCOM4_UART_DRIVER &whal_Pic32czUart_Driver
 
 #define WHAL_PIC32CZ_SUPPLY_PLL     \
     .enableMask = (1UL << 18),        \
diff --git a/wolfHAL/platform/st/stm32c031xx.h b/wolfHAL/platform/st/stm32c031xx.h
index 5843bbb..9a5d35e 100644
--- a/wolfHAL/platform/st/stm32c031xx.h
+++ b/wolfHAL/platform/st/stm32c031xx.h
@@ -25,47 +25,35 @@
 
 /* --- Device macros --- */
 
-#define WHAL_STM32C031_RCC_DEVICE       \
-    .regmap = {                         \
-        .base = 0x40021000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32c0Rcc_Driver
-
-#define WHAL_STM32C031_GPIO_DEVICE      \
-    .regmap = {                         \
-        .base = 0x50000000,             \
-        .size = 0x1800,                 \
-    },                                  \
-    .driver = &whal_Stm32c0Gpio_Driver
-
-#define WHAL_STM32C031_USART1_DEVICE    \
-    .regmap = {                         \
-        .base = 0x40013800,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32c0Uart_Driver
-
-#define WHAL_STM32C031_USART2_DEVICE    \
-    .regmap = {                         \
-        .base = 0x40004400,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32c0Uart_Driver
-
-#define WHAL_STM32C031_SPI1_DEVICE      \
-    .regmap = {                         \
-        .base = 0x40013000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32c0Spi_Driver
-
-#define WHAL_STM32C031_FLASH_DEVICE     \
-    .regmap = {                         \
-        .base = 0x40022000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32c0Flash_Driver
+#define WHAL_STM32C031_RCC_REGMAP       \
+    .base = 0x40021000,                 \
+    .size = 0x400
+#define WHAL_STM32C031_RCC_DRIVER &whal_Stm32c0Rcc_Driver
+
+#define WHAL_STM32C031_GPIO_REGMAP      \
+    .base = 0x50000000,                 \
+    .size = 0x1800
+#define WHAL_STM32C031_GPIO_DRIVER &whal_Stm32c0Gpio_Driver
+
+#define WHAL_STM32C031_USART1_REGMAP    \
+    .base = 0x40013800,                 \
+    .size = 0x400
+#define WHAL_STM32C031_USART1_DRIVER &whal_Stm32c0Uart_Driver
+
+#define WHAL_STM32C031_USART2_REGMAP    \
+    .base = 0x40004400,                 \
+    .size = 0x400
+#define WHAL_STM32C031_USART2_DRIVER &whal_Stm32c0Uart_Driver
+
+#define WHAL_STM32C031_SPI1_REGMAP      \
+    .base = 0x40013000,                 \
+    .size = 0x400
+#define WHAL_STM32C031_SPI1_DRIVER &whal_Stm32c0Spi_Driver
+
+#define WHAL_STM32C031_FLASH_REGMAP     \
+    .base = 0x40022000,                 \
+    .size = 0x400
+#define WHAL_STM32C031_FLASH_DRIVER &whal_Stm32c0Flash_Driver
 
 /* --- Clock gate macros --- */
 
diff --git a/wolfHAL/platform/st/stm32f411xx.h b/wolfHAL/platform/st/stm32f411xx.h
index 1b36b7c..7cfcc06 100644
--- a/wolfHAL/platform/st/stm32f411xx.h
+++ b/wolfHAL/platform/st/stm32f411xx.h
@@ -28,40 +28,30 @@
 
 /* --- Device macros --- */
 
-#define WHAL_STM32F411_RCC_PLL_DEVICE   \
-    .regmap = {                         \
-        .base = 0x40023800,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32f4RccPll_Driver
-
-#define WHAL_STM32F411_GPIO_DEVICE      \
-    .regmap = {                         \
-        .base = 0x40020000,             \
-        .size = 0x2000,                 \
-    },                                  \
-    .driver = &whal_Stm32f4Gpio_Driver
-
-#define WHAL_STM32F411_USART1_DEVICE    \
-    .regmap = {                         \
-        .base = 0x40011000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32f4Uart_Driver
-
-#define WHAL_STM32F411_USART2_DEVICE    \
-    .regmap = {                         \
-        .base = 0x40004400,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32f4Uart_Driver
-
-#define WHAL_STM32F411_USART6_DEVICE    \
-    .regmap = {                         \
-        .base = 0x40011400,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32f4Uart_Driver
+#define WHAL_STM32F411_RCC_PLL_REGMAP   \
+    .base = 0x40023800,                 \
+    .size = 0x400
+#define WHAL_STM32F411_RCC_PLL_DRIVER &whal_Stm32f4RccPll_Driver
+
+#define WHAL_STM32F411_GPIO_REGMAP      \
+    .base = 0x40020000,                 \
+    .size = 0x2000
+#define WHAL_STM32F411_GPIO_DRIVER &whal_Stm32f4Gpio_Driver
+
+#define WHAL_STM32F411_USART1_REGMAP    \
+    .base = 0x40011000,                 \
+    .size = 0x400
+#define WHAL_STM32F411_USART1_DRIVER &whal_Stm32f4Uart_Driver
+
+#define WHAL_STM32F411_USART2_REGMAP    \
+    .base = 0x40004400,                 \
+    .size = 0x400
+#define WHAL_STM32F411_USART2_DRIVER &whal_Stm32f4Uart_Driver
+
+#define WHAL_STM32F411_USART6_REGMAP    \
+    .base = 0x40011400,                 \
+    .size = 0x400
+#define WHAL_STM32F411_USART6_DRIVER &whal_Stm32f4Uart_Driver
 
 /* --- Clock gate macros --- */
 /* RCC_AHB1ENR (offset 0x030) */
@@ -134,27 +124,21 @@
 
 /* SPI device macros */
 
-#define WHAL_STM32F411_SPI1_DEVICE  \
-    .regmap = {                     \
-        .base = 0x40013000,         \
-        .size = 0x400,              \
-    },                              \
-    .driver = &whal_Stm32f4Spi_Driver
+#define WHAL_STM32F411_SPI1_REGMAP  \
+    .base = 0x40013000,             \
+    .size = 0x400
+#define WHAL_STM32F411_SPI1_DRIVER &whal_Stm32f4Spi_Driver
 
-#define WHAL_STM32F411_SPI2_DEVICE  \
-    .regmap = {                     \
-        .base = 0x40003800,         \
-        .size = 0x400,              \
-    },                              \
-    .driver = &whal_Stm32f4Spi_Driver
+#define WHAL_STM32F411_SPI2_REGMAP  \
+    .base = 0x40003800,             \
+    .size = 0x400
+#define WHAL_STM32F411_SPI2_DRIVER &whal_Stm32f4Spi_Driver
 
 /* Flash device macros */
 
-#define WHAL_STM32F411_FLASH_DEVICE \
-    .regmap = {                     \
-        .base = 0x40023C00,         \
-        .size = 0x400,              \
-    },                              \
-    .driver = &whal_Stm32f4Flash_Driver
+#define WHAL_STM32F411_FLASH_REGMAP \
+    .base = 0x40023C00,             \
+    .size = 0x400
+#define WHAL_STM32F411_FLASH_DRIVER &whal_Stm32f4Flash_Driver
 
 #endif /* WHAL_STM32F411XX_H */
diff --git a/wolfHAL/platform/st/stm32h563xx.h b/wolfHAL/platform/st/stm32h563xx.h
index 57f4b81..ab6fc15 100644
--- a/wolfHAL/platform/st/stm32h563xx.h
+++ b/wolfHAL/platform/st/stm32h563xx.h
@@ -27,47 +27,35 @@
 
 /* --- Device macros --- */
 
-#define WHAL_STM32H563_RCC_PLL_DEVICE   \
-    .regmap = {                         \
-        .base = 0x44020C00,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32h5RccPll_Driver
-
-#define WHAL_STM32H563_RCC_HSI_DEVICE   \
-    .regmap = {                         \
-        .base = 0x44020C00,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32h5RccHsi_Driver
-
-#define WHAL_STM32H563_GPIO_DEVICE      \
-    .regmap = {                         \
-        .base = 0x42020000,             \
-        .size = 0x2400,                 \
-    },                                  \
-    .driver = &whal_Stm32h5Gpio_Driver
-
-#define WHAL_STM32H563_USART1_DEVICE    \
-    .regmap = {                         \
-        .base = 0x40013800,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32h5Uart_Driver
-
-#define WHAL_STM32H563_USART2_DEVICE    \
-    .regmap = {                         \
-        .base = 0x40004400,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32h5Uart_Driver
-
-#define WHAL_STM32H563_USART3_DEVICE    \
-    .regmap = {                         \
-        .base = 0x40004800,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32h5Uart_Driver
+#define WHAL_STM32H563_RCC_PLL_REGMAP   \
+    .base = 0x44020C00,                 \
+    .size = 0x400
+#define WHAL_STM32H563_RCC_PLL_DRIVER &whal_Stm32h5RccPll_Driver
+
+#define WHAL_STM32H563_RCC_HSI_REGMAP   \
+    .base = 0x44020C00,                 \
+    .size = 0x400
+#define WHAL_STM32H563_RCC_HSI_DRIVER &whal_Stm32h5RccHsi_Driver
+
+#define WHAL_STM32H563_GPIO_REGMAP      \
+    .base = 0x42020000,                 \
+    .size = 0x2400
+#define WHAL_STM32H563_GPIO_DRIVER &whal_Stm32h5Gpio_Driver
+
+#define WHAL_STM32H563_USART1_REGMAP    \
+    .base = 0x40013800,                 \
+    .size = 0x400
+#define WHAL_STM32H563_USART1_DRIVER &whal_Stm32h5Uart_Driver
+
+#define WHAL_STM32H563_USART2_REGMAP    \
+    .base = 0x40004400,                 \
+    .size = 0x400
+#define WHAL_STM32H563_USART2_DRIVER &whal_Stm32h5Uart_Driver
+
+#define WHAL_STM32H563_USART3_REGMAP    \
+    .base = 0x40004800,                 \
+    .size = 0x400
+#define WHAL_STM32H563_USART3_DRIVER &whal_Stm32h5Uart_Driver
 
 /* --- Clock gate macros --- */
 /* RCC_AHB2ENR (offset 0x08C) */
@@ -150,21 +138,17 @@
 
 /* SPI device macros */
 
-#define WHAL_STM32H563_SPI1_DEVICE  \
-    .regmap = {                     \
-        .base = 0x40013000,         \
-        .size = 0x400,              \
-    },                              \
-    .driver = &whal_Stm32h5Spi_Driver
+#define WHAL_STM32H563_SPI1_REGMAP  \
+    .base = 0x40013000,             \
+    .size = 0x400
+#define WHAL_STM32H563_SPI1_DRIVER &whal_Stm32h5Spi_Driver
 
 /* RNG device macros */
 
-#define WHAL_STM32H563_RNG_DEVICE   \
-    .regmap = {                     \
-        .base = 0x420C0800,         \
-        .size = 0x400,              \
-    },                              \
-    .driver = &whal_Stm32h5Rng_Driver
+#define WHAL_STM32H563_RNG_REGMAP   \
+    .base = 0x420C0800,             \
+    .size = 0x400
+#define WHAL_STM32H563_RNG_DRIVER &whal_Stm32h5Rng_Driver
 
 /* RCC_AHB2ENR (offset 0x08C), bit 18 */
 #define WHAL_STM32H563_RNG_CLOCK    \
@@ -174,12 +158,10 @@
 
 /* Flash device macros */
 
-#define WHAL_STM32H563_FLASH_DEVICE \
-    .regmap = {                     \
-        .base = 0x40022000,         \
-        .size = 0x400,              \
-    },                              \
-    .driver = &whal_Stm32h5Flash_Driver
+#define WHAL_STM32H563_FLASH_REGMAP \
+    .base = 0x40022000,             \
+    .size = 0x400
+#define WHAL_STM32H563_FLASH_DRIVER &whal_Stm32h5Flash_Driver
 
 /* RCC_APB3ENR (offset 0x0A8), bit 1 */
 #define WHAL_STM32H563_SBS_CLOCK    \
@@ -189,12 +171,10 @@
 
 /* Ethernet device macros */
 
-#define WHAL_STM32H563_ETH_DEVICE   \
-    .regmap = {                     \
-        .base = 0x40028000,         \
-        .size = 0x1200,             \
-    },                              \
-    .driver = &whal_Stm32h5Eth_Driver
+#define WHAL_STM32H563_ETH_REGMAP   \
+    .base = 0x40028000,             \
+    .size = 0x1200
+#define WHAL_STM32H563_ETH_DRIVER &whal_Stm32h5Eth_Driver
 
 /* RCC_AHB1ENR (offset 0x088), bit 19 */
 #define WHAL_STM32H563_ETH_CLOCK    \
diff --git a/wolfHAL/platform/st/stm32wb55xx.h b/wolfHAL/platform/st/stm32wb55xx.h
index f4ee4ca..942d276 100644
--- a/wolfHAL/platform/st/stm32wb55xx.h
+++ b/wolfHAL/platform/st/stm32wb55xx.h
@@ -21,110 +21,80 @@
  * @brief Convenience initializers for STM32WB55xx device instances.
  */
 
-#define WHAL_STM32WB55_LPUART1_DEVICE   \
-    .regmap = {                         \
-        .base = 0x40008000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbUart_Driver
-
-#define WHAL_STM32WB55_SPI1_DEVICE      \
-    .regmap = {                         \
-        .base = 0x40013000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbSpi_Driver
-
-#define WHAL_STM32WB55_UART1_DEVICE     \
-    .regmap = {                         \
-        .base = 0x40013800,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbUart_Driver
-
-#define WHAL_STM32WB55_GPIO_DEVICE      \
-    .regmap = {                         \
-        .base = 0x48000000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbGpio_Driver
-
-#define WHAL_STM32WB55_RCC_PLL_DEVICE   \
-    .regmap = {                         \
-        .base = 0x58000000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbRccPll_Driver
-
-#define WHAL_STM32WB55_RCC_MSI_DEVICE   \
-    .regmap = {                         \
-        .base = 0x58000000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbRccPll_Driver
-
-#define WHAL_STM32WB55_RNG_DEVICE       \
-    .regmap = {                         \
-        .base = 0x58001000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbRng_Driver
-
-#define WHAL_STM32WB55_AES1_DEVICE      \
-    .regmap = {                         \
-        .base = 0x50060000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbAes_Driver
-
-#define WHAL_STM32WB55_I2C1_DEVICE      \
-    .regmap = {                         \
-        .base = 0x40005400,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbI2c_Driver
-
-#define WHAL_STM32WB55_I2C3_DEVICE      \
-    .regmap = {                         \
-        .base = 0x40005C00,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbI2c_Driver
-
-#define WHAL_STM32WB55_IWDG_DEVICE      \
-    .regmap = {                         \
-        .base = 0x40003000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbIwdg_Driver
-
-#define WHAL_STM32WB55_WWDG_DEVICE     \
-    .regmap = {                         \
-        .base = 0x40002C00,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbWwdg_Driver
-
-#define WHAL_STM32WB55_FLASH_DEVICE     \
-    .regmap = {                         \
-        .base = 0x58004000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbFlash_Driver
-
-#define WHAL_STM32WB55_DMA1_DEVICE      \
-    .regmap = {                         \
-        .base = 0x40020000,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbDma_Driver
-
-#define WHAL_STM32WB55_DMA2_DEVICE      \
-    .regmap = {                         \
-        .base = 0x40020400,             \
-        .size = 0x400,                  \
-    },                                  \
-    .driver = &whal_Stm32wbDma_Driver
+#define WHAL_STM32WB55_LPUART1_REGMAP   \
+    .base = 0x40008000,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_LPUART1_DRIVER &whal_Stm32wbUart_Driver
+
+#define WHAL_STM32WB55_SPI1_REGMAP      \
+    .base = 0x40013000,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_SPI1_DRIVER &whal_Stm32wbSpi_Driver
+
+#define WHAL_STM32WB55_UART1_REGMAP     \
+    .base = 0x40013800,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_UART1_DRIVER &whal_Stm32wbUart_Driver
+
+#define WHAL_STM32WB55_GPIO_REGMAP      \
+    .base = 0x48000000,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_GPIO_DRIVER &whal_Stm32wbGpio_Driver
+
+#define WHAL_STM32WB55_RCC_PLL_REGMAP   \
+    .base = 0x58000000,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_RCC_PLL_DRIVER &whal_Stm32wbRccPll_Driver
+
+#define WHAL_STM32WB55_RCC_MSI_REGMAP   \
+    .base = 0x58000000,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_RCC_MSI_DRIVER &whal_Stm32wbRccMsi_Driver
+
+#define WHAL_STM32WB55_RNG_REGMAP       \
+    .base = 0x58001000,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_RNG_DRIVER &whal_Stm32wbRng_Driver
+
+#define WHAL_STM32WB55_AES1_REGMAP      \
+    .base = 0x50060000,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_AES1_DRIVER &whal_Stm32wbAes_Driver
+
+#define WHAL_STM32WB55_I2C1_REGMAP      \
+    .base = 0x40005400,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_I2C1_DRIVER &whal_Stm32wbI2c_Driver
+
+#define WHAL_STM32WB55_I2C3_REGMAP      \
+    .base = 0x40005C00,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_I2C3_DRIVER &whal_Stm32wbI2c_Driver
+
+#define WHAL_STM32WB55_IWDG_REGMAP      \
+    .base = 0x40003000,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_IWDG_DRIVER &whal_Stm32wbIwdg_Driver
+
+#define WHAL_STM32WB55_WWDG_REGMAP      \
+    .base = 0x40002C00,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_WWDG_DRIVER &whal_Stm32wbWwdg_Driver
+
+#define WHAL_STM32WB55_FLASH_REGMAP     \
+    .base = 0x58004000,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_FLASH_DRIVER &whal_Stm32wbFlash_Driver
+
+#define WHAL_STM32WB55_DMA1_REGMAP      \
+    .base = 0x40020000,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_DMA1_DRIVER &whal_Stm32wbDma_Driver
+
+#define WHAL_STM32WB55_DMA2_REGMAP      \
+    .base = 0x40020400,                 \
+    .size = 0x400
+#define WHAL_STM32WB55_DMA2_DRIVER &whal_Stm32wbDma_Driver
 
 #define WHAL_STM32WB55_DMA1_CFG         \
     .dmamuxBase = 0x40020800,           \
diff --git a/wolfHAL/rng/rng.h b/wolfHAL/rng/rng.h
index d1906ec..9227f55 100644
--- a/wolfHAL/rng/rng.h
+++ b/wolfHAL/rng/rng.h
@@ -40,7 +40,8 @@ struct whal_Rng {
  * @param rngDev RNG instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 #ifdef WHAL_CFG_DIRECT_CALLBACKS
 #define whal_Rng_Init(rngDev) ((rngDev)->driver->Init((rngDev)))
@@ -54,7 +55,8 @@ struct whal_Rng {
  * @param rngDev RNG instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Rng_Init(whal_Rng *rngDev);
 /*
@@ -63,7 +65,8 @@ whal_Error whal_Rng_Init(whal_Rng *rngDev);
  * @param rngDev RNG instance to deinitialize.
  *
  * @retval WHAL_SUCCESS Driver-specific deinit completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Rng_Deinit(whal_Rng *rngDev);
 /*
@@ -74,7 +77,8 @@ whal_Error whal_Rng_Deinit(whal_Rng *rngDev);
  * @param rngDataSz Number of random bytes to generate.
  *
  * @retval WHAL_SUCCESS Buffer filled with random data.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Rng_Generate(whal_Rng *rngDev, void *rngData, size_t rngDataSz);
 #endif
diff --git a/wolfHAL/rng/stm32h5_rng.h b/wolfHAL/rng/stm32h5_rng.h
index 5afec3e..a89ccf6 100644
--- a/wolfHAL/rng/stm32h5_rng.h
+++ b/wolfHAL/rng/stm32h5_rng.h
@@ -22,6 +22,7 @@ typedef struct whal_Stm32h5Rng_Cfg {
     whal_Timeout *timeout;
 } whal_Stm32h5Rng_Cfg;
 
+#ifndef WHAL_CFG_RNG_API_MAPPING_STM32H5
 /*
  * @brief Driver instance for STM32H5 RNG peripheral.
  */
@@ -64,5 +65,6 @@ whal_Error whal_Stm32h5Rng_Deinit(whal_Rng *rngDev);
  */
 whal_Error whal_Stm32h5Rng_Generate(whal_Rng *rngDev, void *rngData,
                                      size_t rngDataSz);
+#endif /* !WHAL_CFG_RNG_API_MAPPING_STM32H5 */
 
 #endif /* WHAL_STM32H5_RNG_H */
diff --git a/wolfHAL/rng/stm32wb_rng.h b/wolfHAL/rng/stm32wb_rng.h
index 61c3313..3680595 100644
--- a/wolfHAL/rng/stm32wb_rng.h
+++ b/wolfHAL/rng/stm32wb_rng.h
@@ -21,6 +21,7 @@ typedef struct whal_Stm32wbRng_Cfg {
     whal_Timeout *timeout;
 } whal_Stm32wbRng_Cfg;
 
+#ifndef WHAL_CFG_RNG_API_MAPPING_STM32WB
 /*
  * @brief Driver instance for STM32WB RNG peripheral.
  */
@@ -55,5 +56,6 @@ whal_Error whal_Stm32wbRng_Deinit(whal_Rng *rngDev);
  * @retval WHAL_EINVAL  Invalid arguments or seed/clock error detected.
  */
 whal_Error whal_Stm32wbRng_Generate(whal_Rng *rngDev, void *rngData, size_t rngDataSz);
+#endif /* !WHAL_CFG_RNG_API_MAPPING_STM32WB */
 
 #endif /* WHAL_STM32WB_RNG_H */
diff --git a/wolfHAL/sensor/imu/bmi270_sensor.h b/wolfHAL/sensor/imu/bmi270_sensor.h
index 4d70966..6c54c96 100644
--- a/wolfHAL/sensor/imu/bmi270_sensor.h
+++ b/wolfHAL/sensor/imu/bmi270_sensor.h
@@ -46,6 +46,7 @@ typedef struct {
     void (*DelayMs)(size_t ms);   /* Millisecond delay function */
 } whal_Bmi270_Cfg;
 
+#ifndef WHAL_CFG_SENSOR_API_MAPPING_BMI270
 /*
  * @brief Driver instance for the BMI270.
  */
@@ -90,5 +91,6 @@ whal_Error whal_Bmi270_Deinit(whal_Sensor *dev);
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Bmi270_Read(whal_Sensor *dev, void *data);
+#endif /* !WHAL_CFG_SENSOR_API_MAPPING_BMI270 */
 
 #endif /* WHAL_IMU_BMI270_H */
diff --git a/wolfHAL/spi/spi.h b/wolfHAL/spi/spi.h
index f93db06..931fcdb 100644
--- a/wolfHAL/spi/spi.h
+++ b/wolfHAL/spi/spi.h
@@ -64,7 +64,8 @@ struct whal_Spi {
  * @param spiDev Pointer to the SPI instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or driver rejected configuration.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 #ifdef WHAL_CFG_DIRECT_CALLBACKS
 #define whal_Spi_Init(spiDev) ((spiDev)->driver->Init((spiDev)))
@@ -81,7 +82,8 @@ struct whal_Spi {
  * @param spiDev Pointer to the SPI instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or driver rejected configuration.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Spi_Init(whal_Spi *spiDev);
 /*
@@ -90,7 +92,8 @@ whal_Error whal_Spi_Init(whal_Spi *spiDev);
  * @param spiDev Pointer to the SPI instance to deinitialize.
  *
  * @retval WHAL_SUCCESS Driver-specific deinit completed.
- * @retval WHAL_EINVAL  Null pointer or driver refused to deinit.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Spi_Deinit(whal_Spi *spiDev);
 /*
@@ -103,7 +106,8 @@ whal_Error whal_Spi_Deinit(whal_Spi *spiDev);
  * @param comCfg  Per-session communication parameters.
  *
  * @retval WHAL_SUCCESS Communication session started.
- * @retval WHAL_EINVAL  Null pointer or invalid parameters.
+ * @retval WHAL_EINVAL   Null pointer or invalid parameters.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Spi_StartCom(whal_Spi *spiDev, whal_Spi_ComCfg *comCfg);
 /*
@@ -115,7 +119,8 @@ whal_Error whal_Spi_StartCom(whal_Spi *spiDev, whal_Spi_ComCfg *comCfg);
  * @param spiDev Pointer to the SPI instance.
  *
  * @retval WHAL_SUCCESS Communication session ended.
- * @retval WHAL_EINVAL  Null pointer or driver error.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Spi_EndCom(whal_Spi *spiDev);
 /*
@@ -133,7 +138,8 @@ whal_Error whal_Spi_EndCom(whal_Spi *spiDev);
  * @param rxLen  Number of bytes to receive (0 when rx is NULL).
  *
  * @retval WHAL_SUCCESS Transfer completed.
- * @retval WHAL_EINVAL  Null spiDev or driver failed to transfer.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Spi_SendRecv(whal_Spi *spiDev, const void *tx, size_t txLen, void *rx, size_t rxLen);
 #endif
diff --git a/wolfHAL/spi/stm32c0_spi.h b/wolfHAL/spi/stm32c0_spi.h
index f63f1bb..8a513f7 100644
--- a/wolfHAL/spi/stm32c0_spi.h
+++ b/wolfHAL/spi/stm32c0_spi.h
@@ -14,11 +14,13 @@
 
 typedef whal_Stm32wbSpi_Cfg whal_Stm32c0Spi_Cfg;
 
+#ifndef WHAL_CFG_SPI_API_MAPPING_STM32C0
 #define whal_Stm32c0Spi_Driver   whal_Stm32wbSpi_Driver
 #define whal_Stm32c0Spi_Init     whal_Stm32wbSpi_Init
 #define whal_Stm32c0Spi_Deinit   whal_Stm32wbSpi_Deinit
 #define whal_Stm32c0Spi_StartCom whal_Stm32wbSpi_StartCom
 #define whal_Stm32c0Spi_EndCom   whal_Stm32wbSpi_EndCom
 #define whal_Stm32c0Spi_SendRecv whal_Stm32wbSpi_SendRecv
+#endif /* !WHAL_CFG_SPI_API_MAPPING_STM32C0 */
 
 #endif /* WHAL_STM32C0_SPI_H */
diff --git a/wolfHAL/spi/stm32f4_spi.h b/wolfHAL/spi/stm32f4_spi.h
index 808abb9..c59f469 100644
--- a/wolfHAL/spi/stm32f4_spi.h
+++ b/wolfHAL/spi/stm32f4_spi.h
@@ -31,6 +31,7 @@ typedef struct whal_Stm32f4Spi_Cfg {
     whal_Timeout *timeout;
 } whal_Stm32f4Spi_Cfg;
 
+#ifndef WHAL_CFG_SPI_API_MAPPING_STM32F4
 /*
  * @brief Driver instance for STM32F4 SPI peripheral.
  */
@@ -97,5 +98,6 @@ whal_Error whal_Stm32f4Spi_EndCom(whal_Spi *spiDev);
 whal_Error whal_Stm32f4Spi_SendRecv(whal_Spi *spiDev,
                                      const void *tx, size_t txLen,
                                      void *rx, size_t rxLen);
+#endif /* !WHAL_CFG_SPI_API_MAPPING_STM32F4 */
 
 #endif /* WHAL_STM32F4_SPI_H */
diff --git a/wolfHAL/spi/stm32h5_spi.h b/wolfHAL/spi/stm32h5_spi.h
index f604662..ccf0cfc 100644
--- a/wolfHAL/spi/stm32h5_spi.h
+++ b/wolfHAL/spi/stm32h5_spi.h
@@ -25,6 +25,7 @@ typedef struct whal_Stm32h5Spi_Cfg {
     whal_Timeout *timeout;
 } whal_Stm32h5Spi_Cfg;
 
+#ifndef WHAL_CFG_SPI_API_MAPPING_STM32H5
 /*
  * @brief Driver instance for STM32H5 SPI peripheral.
  */
@@ -96,5 +97,6 @@ whal_Error whal_Stm32h5Spi_EndCom(whal_Spi *spiDev);
  */
 whal_Error whal_Stm32h5Spi_SendRecv(whal_Spi *spiDev, const void *tx,
                                      size_t txLen, void *rx, size_t rxLen);
+#endif /* !WHAL_CFG_SPI_API_MAPPING_STM32H5 */
 
 #endif /* WHAL_STM32H5_SPI_H */
diff --git a/wolfHAL/spi/stm32wb_spi.h b/wolfHAL/spi/stm32wb_spi.h
index f2d555b..8dd24d8 100644
--- a/wolfHAL/spi/stm32wb_spi.h
+++ b/wolfHAL/spi/stm32wb_spi.h
@@ -27,6 +27,8 @@ typedef struct whal_Stm32wbSpi_Cfg {
     whal_Timeout *timeout;
 } whal_Stm32wbSpi_Cfg;
 
+#if !defined(WHAL_CFG_SPI_API_MAPPING_STM32WB) && \
+    !defined(WHAL_CFG_SPI_API_MAPPING_STM32C0)
 /*
  * @brief Driver instance for STM32 SPI peripheral.
  */
@@ -93,5 +95,6 @@ whal_Error whal_Stm32wbSpi_EndCom(whal_Spi *spiDev);
 whal_Error whal_Stm32wbSpi_SendRecv(whal_Spi *spiDev,
                                      const void *tx, size_t txLen,
                                      void *rx, size_t rxLen);
+#endif /* !WHAL_CFG_SPI_API_MAPPING */
 
 #endif /* WHAL_STM32WB_SPI_H */
diff --git a/wolfHAL/supply/pic32cz_supc.h b/wolfHAL/supply/pic32cz_supc.h
index b5053e2..a82555b 100644
--- a/wolfHAL/supply/pic32cz_supc.h
+++ b/wolfHAL/supply/pic32cz_supc.h
@@ -20,6 +20,7 @@ typedef struct whal_Pic32czSupc_Supply {
     size_t enablePos;
 } whal_Pic32czSupc_Supply;
 
+#ifndef WHAL_CFG_SUPPLY_API_MAPPING_PIC32CZ
 /*
  * @brief Driver instance for PIC32CZ SUPC peripheral.
  */
@@ -61,5 +62,6 @@ whal_Error whal_Pic32czSupc_Enable(whal_Supply *supplyCtrl, void *supply);
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Pic32czSupc_Disable(whal_Supply *supplyCtrl, void *supply);
+#endif /* !WHAL_CFG_SUPPLY_API_MAPPING_PIC32CZ */
 
 #endif /* WHAL_PIC32CZ_SUPC_H */
diff --git a/wolfHAL/timer/systick.h b/wolfHAL/timer/systick.h
index bcdb4db..5f056e2 100644
--- a/wolfHAL/timer/systick.h
+++ b/wolfHAL/timer/systick.h
@@ -34,6 +34,7 @@ typedef struct {
     whal_SysTick_TickInt tickInt;
 } whal_SysTick_Cfg;
 
+#ifndef WHAL_CFG_TIMER_API_MAPPING_SYSTICK
 /*
  * @brief Driver instance for the Cortex-M SysTick timer.
  */
@@ -47,7 +48,7 @@ extern const whal_TimerDriver whal_SysTick_Driver;
  * @retval WHAL_SUCCESS Initialization completed.
  * @retval WHAL_EINVAL  Invalid arguments.
  */
-whal_Error SysTick_Init(whal_Timer *timerDev);
+whal_Error whal_SysTick_Init(whal_Timer *timerDev);
 /*
  * @brief Deinitialize the SysTick timer.
  *
@@ -56,7 +57,7 @@ whal_Error SysTick_Init(whal_Timer *timerDev);
  * @retval WHAL_SUCCESS Deinit completed.
  * @retval WHAL_EINVAL  Invalid arguments.
  */
-whal_Error SysTick_Deinit(whal_Timer *timerDev);
+whal_Error whal_SysTick_Deinit(whal_Timer *timerDev);
 /*
  * @brief Start the SysTick counter.
  *
@@ -65,7 +66,7 @@ whal_Error SysTick_Deinit(whal_Timer *timerDev);
  * @retval WHAL_SUCCESS Timer started.
  * @retval WHAL_EINVAL  Invalid arguments.
  */
-whal_Error SysTick_Start(whal_Timer *timerDev);
+whal_Error whal_SysTick_Start(whal_Timer *timerDev);
 /*
  * @brief Stop the SysTick counter.
  *
@@ -74,7 +75,7 @@ whal_Error SysTick_Start(whal_Timer *timerDev);
  * @retval WHAL_SUCCESS Timer stopped.
  * @retval WHAL_EINVAL  Invalid arguments.
  */
-whal_Error SysTick_Stop(whal_Timer *timerDev);
+whal_Error whal_SysTick_Stop(whal_Timer *timerDev);
 /*
  * @brief Reset the SysTick counter state.
  *
@@ -83,6 +84,7 @@ whal_Error SysTick_Stop(whal_Timer *timerDev);
  * @retval WHAL_SUCCESS Timer reset.
  * @retval WHAL_EINVAL  Invalid arguments.
  */
-whal_Error SysTick_Reset(whal_Timer *timerDev);
+whal_Error whal_SysTick_Reset(whal_Timer *timerDev);
+#endif /* !WHAL_CFG_TIMER_API_MAPPING_SYSTICK */
 
 #endif /* WHAL_SYSTICK_H */
diff --git a/wolfHAL/timer/timer.h b/wolfHAL/timer/timer.h
index c6d7049..cbdc43c 100644
--- a/wolfHAL/timer/timer.h
+++ b/wolfHAL/timer/timer.h
@@ -43,7 +43,8 @@ struct whal_Timer{
  * @param timerDev Timer instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 #ifdef WHAL_CFG_DIRECT_CALLBACKS
 #define whal_Timer_Init(timerDev) ((timerDev)->driver->Init((timerDev)))
@@ -58,7 +59,8 @@ struct whal_Timer{
  * @param timerDev Timer instance to initialize.
  *
  * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Timer_Init(whal_Timer *timerDev);
 /*
@@ -67,7 +69,8 @@ whal_Error whal_Timer_Init(whal_Timer *timerDev);
  * @param timerDev Timer instance to deinitialize.
  *
  * @retval WHAL_SUCCESS Driver-specific deinit completed.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Timer_Deinit(whal_Timer *timerDev);
 /*
@@ -76,7 +79,8 @@ whal_Error whal_Timer_Deinit(whal_Timer *timerDev);
  * @param timerDev Timer instance to start.
  *
  * @retval WHAL_SUCCESS Timer started.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Timer_Start(whal_Timer *timerDev);
 /*
@@ -85,7 +89,8 @@ whal_Error whal_Timer_Start(whal_Timer *timerDev);
  * @param timerDev Timer instance to stop.
  *
  * @retval WHAL_SUCCESS Timer stopped.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Timer_Stop(whal_Timer *timerDev);
 /*
@@ -94,7 +99,8 @@ whal_Error whal_Timer_Stop(whal_Timer *timerDev);
  * @param timerDev Timer instance to reset.
  *
  * @retval WHAL_SUCCESS Timer reset.
- * @retval WHAL_EINVAL  Null pointer or missing driver function.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Timer_Reset(whal_Timer *timerDev);
 #endif
diff --git a/wolfHAL/uart/pic32cz_uart.h b/wolfHAL/uart/pic32cz_uart.h
index d13071d..dd550d7 100644
--- a/wolfHAL/uart/pic32cz_uart.h
+++ b/wolfHAL/uart/pic32cz_uart.h
@@ -43,6 +43,7 @@ typedef struct whal_Pic32czUart_Cfg {
     whal_Timeout *timeout;
 } whal_Pic32czUart_Cfg;
 
+#ifndef WHAL_CFG_UART_API_MAPPING_PIC32CZ
 /*
  * @brief Driver instance for PIC32CZ UART.
  */
@@ -88,5 +89,6 @@ whal_Error whal_Pic32czUart_Send(whal_Uart *uartDev, const void *data, size_t da
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Pic32czUart_Recv(whal_Uart *uartDev, void *data, size_t dataSz);
+#endif /* !WHAL_CFG_UART_API_MAPPING_PIC32CZ */
 
 #endif /* WHAL_PIC32CZ_UART_H */
diff --git a/wolfHAL/uart/stm32c0_uart.h b/wolfHAL/uart/stm32c0_uart.h
index edcc0fc..eb8dd84 100644
--- a/wolfHAL/uart/stm32c0_uart.h
+++ b/wolfHAL/uart/stm32c0_uart.h
@@ -30,10 +30,12 @@ typedef whal_Stm32wbUart_Cfg whal_Stm32c0Uart_Cfg;
  */
 #define WHAL_STM32C0_LPUART_BRR(clk, baud) WHAL_STM32WB_LPUART_BRR(clk, baud)
 
+#ifndef WHAL_CFG_UART_API_MAPPING_STM32C0
 #define whal_Stm32c0Uart_Driver whal_Stm32wbUart_Driver
 #define whal_Stm32c0Uart_Init   whal_Stm32wbUart_Init
 #define whal_Stm32c0Uart_Deinit whal_Stm32wbUart_Deinit
 #define whal_Stm32c0Uart_Send   whal_Stm32wbUart_Send
 #define whal_Stm32c0Uart_Recv   whal_Stm32wbUart_Recv
+#endif /* !WHAL_CFG_UART_API_MAPPING_STM32C0 */
 
 #endif /* WHAL_STM32C0_UART_H */
diff --git a/wolfHAL/uart/stm32f4_uart.h b/wolfHAL/uart/stm32f4_uart.h
index bc123f8..9ecd713 100644
--- a/wolfHAL/uart/stm32f4_uart.h
+++ b/wolfHAL/uart/stm32f4_uart.h
@@ -42,6 +42,7 @@ typedef struct whal_Stm32f4Uart_Cfg {
     whal_Timeout *timeout;
 } whal_Stm32f4Uart_Cfg;
 
+#ifndef WHAL_CFG_UART_API_MAPPING_STM32F4
 /*
  * @brief Driver instance for STM32F4 UART peripheral.
  */
@@ -90,5 +91,6 @@ whal_Error whal_Stm32f4Uart_Send(whal_Uart *uartDev, const void *data, size_t da
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Stm32f4Uart_Recv(whal_Uart *uartDev, void *data, size_t dataSz);
+#endif /* !WHAL_CFG_UART_API_MAPPING_STM32F4 */
 
 #endif /* WHAL_STM32F4_UART_H */
diff --git a/wolfHAL/uart/stm32h5_uart.h b/wolfHAL/uart/stm32h5_uart.h
index ebaa139..d4e40e0 100644
--- a/wolfHAL/uart/stm32h5_uart.h
+++ b/wolfHAL/uart/stm32h5_uart.h
@@ -30,10 +30,12 @@ typedef whal_Stm32wbUart_Cfg whal_Stm32h5Uart_Cfg;
  */
 #define WHAL_STM32H5_LPUART_BRR(clk, baud) WHAL_STM32WB_LPUART_BRR(clk, baud)
 
+#ifndef WHAL_CFG_UART_API_MAPPING_STM32H5
 #define whal_Stm32h5Uart_Driver whal_Stm32wbUart_Driver
 #define whal_Stm32h5Uart_Init   whal_Stm32wbUart_Init
 #define whal_Stm32h5Uart_Deinit whal_Stm32wbUart_Deinit
 #define whal_Stm32h5Uart_Send   whal_Stm32wbUart_Send
 #define whal_Stm32h5Uart_Recv   whal_Stm32wbUart_Recv
+#endif /* !WHAL_CFG_UART_API_MAPPING_STM32H5 */
 
 #endif /* WHAL_STM32H5_UART_H */
diff --git a/wolfHAL/uart/stm32wb_uart.h b/wolfHAL/uart/stm32wb_uart.h
index 637836e..75eaa84 100644
--- a/wolfHAL/uart/stm32wb_uart.h
+++ b/wolfHAL/uart/stm32wb_uart.h
@@ -30,6 +30,10 @@ typedef struct whal_Stm32wbUart_Cfg {
     whal_Timeout *timeout;
 } whal_Stm32wbUart_Cfg;
 
+#if !defined(WHAL_CFG_UART_API_MAPPING_STM32WB) && \
+    !defined(WHAL_CFG_UART_API_MAPPING_STM32WB_DMA) && \
+    !defined(WHAL_CFG_UART_API_MAPPING_STM32H5) && \
+    !defined(WHAL_CFG_UART_API_MAPPING_STM32C0)
 /*
  * @brief Polled UART driver. Implements Init, Deinit, Send, Recv.
  */
@@ -78,5 +82,6 @@ whal_Error whal_Stm32wbUart_Send(whal_Uart *uartDev, const void *data, size_t da
  * @retval WHAL_EINVAL  Invalid arguments.
  */
 whal_Error whal_Stm32wbUart_Recv(whal_Uart *uartDev, void *data, size_t dataSz);
+#endif /* !WHAL_CFG_UART_API_MAPPING */
 
 #endif /* WHAL_STM32WB_UART_H */
diff --git a/wolfHAL/uart/stm32wb_uart_dma.h b/wolfHAL/uart/stm32wb_uart_dma.h
index e883e41..e1a3d4e 100644
--- a/wolfHAL/uart/stm32wb_uart_dma.h
+++ b/wolfHAL/uart/stm32wb_uart_dma.h
@@ -29,6 +29,7 @@ typedef struct {
     volatile whal_Error rxResult;
 } whal_Stm32wbUartDma_Cfg;
 
+#ifndef WHAL_CFG_UART_API_MAPPING_STM32WB_DMA
 /*
  * @brief DMA-backed UART driver. Implements Init, Deinit, Send, Recv,
  *        SendAsync, RecvAsync.
@@ -100,6 +101,7 @@ whal_Error whal_Stm32wbUartDma_SendAsync(whal_Uart *uartDev, const void *data,
  */
 whal_Error whal_Stm32wbUartDma_RecvAsync(whal_Uart *uartDev, void *data,
                                           size_t dataSz);
+#endif /* !WHAL_CFG_UART_API_MAPPING_STM32WB_DMA */
 
 /*
  * @brief DMA TX completion callback for use with whal_Stm32wbDma_IRQHandler.
diff --git a/wolfHAL/uart/uart.h b/wolfHAL/uart/uart.h
index 36b8a85..65bb4a9 100644
--- a/wolfHAL/uart/uart.h
+++ b/wolfHAL/uart/uart.h
@@ -25,9 +25,9 @@ typedef struct {
     whal_Error (*Send)(whal_Uart *uartDev, const void *data, size_t dataSz);
     /* Receive into a buffer. */
     whal_Error (*Recv)(whal_Uart *uartDev, void *data, size_t dataSz);
-    /* Start an asynchronous transmit. Returns immediately. */
+    /* Start an asynchronous transmit. NULL if not supported. */
     whal_Error (*SendAsync)(whal_Uart *uartDev, const void *data, size_t dataSz);
-    /* Start an asynchronous receive. Returns immediately. */
+    /* Start an asynchronous receive. NULL if not supported. */
     whal_Error (*RecvAsync)(whal_Uart *uartDev, void *data, size_t dataSz);
 } whal_UartDriver;
 
@@ -53,8 +53,9 @@ struct whal_Uart {
  *
  * @param uartDev Pointer to the UART instance to initialize.
  *
- * @retval WHAL_SUCCESS Driver-specific init completed.
- * @retval WHAL_EINVAL  Null pointer or driver rejected configuration.
+ * @retval WHAL_SUCCESS  Driver-specific init completed.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Uart_Init(whal_Uart *uartDev);
 
@@ -63,8 +64,9 @@ whal_Error whal_Uart_Init(whal_Uart *uartDev);
  *
  * @param uartDev Pointer to the UART instance to deinitialize.
  *
- * @retval WHAL_SUCCESS Driver-specific deinit completed.
- * @retval WHAL_EINVAL  Null pointer or driver refused to deinit.
+ * @retval WHAL_SUCCESS  Driver-specific deinit completed.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Uart_Deinit(whal_Uart *uartDev);
 
@@ -75,8 +77,9 @@ whal_Error whal_Uart_Deinit(whal_Uart *uartDev);
  * @param data    Buffer to transmit.
  * @param dataSz  Number of bytes to send.
  *
- * @retval WHAL_SUCCESS Buffer was queued or transmitted.
- * @retval WHAL_EINVAL  Null pointer or driver failed to send.
+ * @retval WHAL_SUCCESS  Buffer was queued or transmitted.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Uart_Send(whal_Uart *uartDev, const void *data, size_t dataSz);
 
@@ -87,8 +90,9 @@ whal_Error whal_Uart_Send(whal_Uart *uartDev, const void *data, size_t dataSz);
  * @param data    Destination buffer.
  * @param dataSz  Maximum number of bytes to read.
  *
- * @retval WHAL_SUCCESS Buffer was filled or receive started.
- * @retval WHAL_EINVAL  Null pointer or driver failed to receive.
+ * @retval WHAL_SUCCESS  Buffer was filled or receive started.
+ * @retval WHAL_EINVAL   Null pointer.
+ * @retval WHAL_ENOTIMPL Operation not implemented by this driver.
  */
 whal_Error whal_Uart_Recv(whal_Uart *uartDev, void *data, size_t dataSz);
 
@@ -97,15 +101,15 @@ whal_Error whal_Uart_Recv(whal_Uart *uartDev, void *data, size_t dataSz);
  *
  * Returns immediately. The buffer must remain valid until the transfer
  * completes. Completion signaling is driver-specific (e.g., a status
- * field in the driver config). Drivers that do not support async return
- * WHAL_EINVAL.
+ * field in the driver config).
  *
  * @param uartDev Pointer to the UART instance.
  * @param data    Buffer to transmit. Must remain valid until completion.
  * @param dataSz  Number of bytes to send.
  *
- * @retval WHAL_SUCCESS Transfer started.
- * @retval WHAL_EINVAL  Null pointer or async not supported.
+ * @retval WHAL_SUCCESS   Transfer started.
+ * @retval WHAL_EINVAL    Invalid arguments.
+ * @retval WHAL_ENOTIMPL  Async not supported by this driver.
  */
 whal_Error whal_Uart_SendAsync(whal_Uart *uartDev, const void *data, size_t dataSz);
 
@@ -114,15 +118,15 @@ whal_Error whal_Uart_SendAsync(whal_Uart *uartDev, const void *data, size_t data
  *
  * Returns immediately. The buffer must remain valid until the transfer
  * completes. Completion signaling is driver-specific (e.g., a status
- * field in the driver config). Drivers that do not support async return
- * WHAL_EINVAL.
+ * field in the driver config).
  *
  * @param uartDev Pointer to the UART instance.
  * @param data    Receive buffer. Must remain valid until completion.
  * @param dataSz  Number of bytes to receive.
  *
- * @retval WHAL_SUCCESS Receive started.
- * @retval WHAL_EINVAL  Null pointer or async not supported.
+ * @retval WHAL_SUCCESS   Receive started.
+ * @retval WHAL_EINVAL    Invalid arguments.
+ * @retval WHAL_ENOTIMPL  Async not supported by this driver.
  */
 whal_Error whal_Uart_RecvAsync(whal_Uart *uartDev, void *data, size_t dataSz);
 #endif
diff --git a/wolfHAL/watchdog/stm32wb_iwdg.h b/wolfHAL/watchdog/stm32wb_iwdg.h
index 9701206..dad52e2 100644
--- a/wolfHAL/watchdog/stm32wb_iwdg.h
+++ b/wolfHAL/watchdog/stm32wb_iwdg.h
@@ -35,6 +35,7 @@ typedef struct {
     whal_Timeout *timeout;
 } whal_Stm32wbIwdg_Cfg;
 
+#ifndef WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_IWDG
 /*
  * @brief Driver instance for STM32WB IWDG.
  */
@@ -76,5 +77,6 @@ whal_Error whal_Stm32wbIwdg_Deinit(whal_Watchdog *wdgDev);
  * @retval WHAL_EINVAL  Null pointer.
  */
 whal_Error whal_Stm32wbIwdg_Refresh(whal_Watchdog *wdgDev);
+#endif /* !WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_IWDG */
 
 #endif /* WHAL_STM32WB_IWDG_H */
diff --git a/wolfHAL/watchdog/stm32wb_wwdg.h b/wolfHAL/watchdog/stm32wb_wwdg.h
index f1d2000..b772b25 100644
--- a/wolfHAL/watchdog/stm32wb_wwdg.h
+++ b/wolfHAL/watchdog/stm32wb_wwdg.h
@@ -36,6 +36,7 @@ typedef struct {
     uint8_t counter;      /* 7-bit counter value (must be > 0x3F) */
 } whal_Stm32wbWwdg_Cfg;
 
+#ifndef WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_WWDG
 /*
  * @brief Driver instance for STM32WB WWDG.
  */
@@ -76,5 +77,6 @@ whal_Error whal_Stm32wbWwdg_Deinit(whal_Watchdog *wdgDev);
  * @retval WHAL_EINVAL  Null pointer.
  */
 whal_Error whal_Stm32wbWwdg_Refresh(whal_Watchdog *wdgDev);
+#endif /* !WHAL_CFG_WATCHDOG_API_MAPPING_STM32WB_WWDG */
 
 #endif /* WHAL_STM32WB_WWDG_H */