Add external flash support and dual-bank flash swap functionality for PSoC6 devices.

Removed NVM_FLASH_WRITEONCE restriction for psoc6.
Update flash hal functions to support read-modify-erase-write way to perform the programming of flash.

Author: Pushyanth-Infineon

config/examples/cypsoc6.config

@@ -14,7 +14,7 @@ SPI_FLASH?=0
 NO_XIP?=0
 UART_FLASH?=0
 ALLOW_DOWNGRADE?=0
-NVM_FLASH_WRITEONCE?=1
+NVM_FLASH_WRITEONCE?=0
 WOLFBOOT_VERSION?=0
 V?=0
 SPMATH?=1
@@ -27,4 +27,4 @@ WOLFBOOT_PARTITION_SIZE?=0x80000
 WOLFBOOT_SECTOR_SIZE?=512
 WOLFBOOT_PARTITION_BOOT_ADDRESS?=0x10080000
 WOLFBOOT_PARTITION_UPDATE_ADDRESS?=0x10100000
-WOLFBOOT_PARTITION_SWAP_ADDRESS?=10010000
+WOLFBOOT_PARTITION_SWAP_ADDRESS?=0x10010000

docs/Targets.md

@@ -2377,7 +2377,6 @@ The following configuration has been tested on the PSoC CY8CKIT-62S2-43012:
 
 ```
 make TARGET=psoc6 \
-    NVM_FLASH_WRITEONCE=1 \
     CYPRESS_PDL=./lib/psoc6pdl \
     CYPRESS_TARGET_LIB=./lib/TARGET_CY8CKIT-062S2-43012 \
     CYPRESS_CORE_LIB=./lib/core-lib \
@@ -2394,6 +2393,34 @@ To compile with hardware acceleration disabled, use the option
 
 in your wolfBoot configuration.
 
+#### External Flash Support
+
+PSoC6 supports external QSPI flash for firmware storage. To enable:
+
+```
+make TARGET=psoc6 \
+    EXT_FLASH=1 \
+    CYPRESS_PDL=./lib/psoc6pdl \
+    CYPRESS_TARGET_LIB=./lib/TARGET_CY8CKIT-062S2-43012 \
+    CYPRESS_CORE_LIB=./lib/core-lib \
+    WOLFBOOT_SECTOR_SIZE=4096
+```
+
+External flash uses a temporary sector backup mechanism to handle the larger erase size (0x40000 bytes) compared to internal flash rows. The backup sector is automatically managed in external flash beyond the update partition.
+
+#### Dual-Bank Flash Swap
+
+PSoC6 supports hardware-assisted bank swapping for faster and more reliable firmware updates:
+
+```
+make TARGET=psoc6 \
+    DUALBANK_SWAP=1 \
+    CYPRESS_PDL=./lib/psoc6pdl \
+    CYPRESS_TARGET_LIB=./lib/TARGET_CY8CKIT-062S2-43012 \
+    CYPRESS_CORE_LIB=./lib/core-lib \
+    WOLFBOOT_SECTOR_SIZE=4096
+```
+
 #### OpenOCD installation
 
 Compile and install the customized OpenOCD.