Local Kinetis stuff

Author: mattia-moffa

config/examples/kinetis-kl26-lms-small.config

@@ -0,0 +1,49 @@
+ARCH?=ARM
+TARGET?=kinetis_kl26
+SIGN?=LMS
+HASH?=SHA256
+
+LMS_LEVELS=1
+LMS_HEIGHT=10
+LMS_WINTERNITZ=8
+IMAGE_SIGNATURE_SIZE=1456
+# Keytools (sign.c) forces header_sz >= 2 * sig_sz for LMS, so the minimum
+# is 3552; round up to the next power of two.
+IMAGE_HEADER_SIZE=4096
+
+MCUXSDK?=0
+MCUXPRESSO?=$(PWD)/../NXP/SDK_2_2_0_FRDM-KL26Z
+MCUXPRESSO_CMSIS?=$(MCUXPRESSO)/CMSIS
+MCUXPRESSO_CPU?=MKL26Z128VLH4
+MCUXPRESSO_DRIVERS?=$(MCUXPRESSO)/devices/MKL26Z4
+DEBUG?=0
+VTOR?=1
+CORTEX_M0?=1
+NO_ASM?=0
+EXT_FLASH?=0
+SPI_FLASH?=0
+ALLOW_DOWNGRADE?=0
+NVM_FLASH_WRITEONCE?=1
+WOLFBOOT_VERSION?=0
+V?=0
+SPMATH?=1
+RAM_CODE?=0
+DUALBANK_SWAP?=0
+PKA?=0
+DEBUG_UART?=1
+
+# Cortex-M0+ doesn't support unaligned word accesses. WOLFSSL_USE_ALIGN
+# routes word-sized hash operations through byte-safe code paths when the
+# buffers (e.g. LMS internal hash state) aren't 4-byte aligned.
+CFLAGS_EXTRA+=-DWOLFSSL_USE_ALIGN
+
+# Logical sector = 4 KL26 hardware sectors (1KB each). Required because
+# IMAGE_HEADER_SIZE (4096) must be <= WOLFBOOT_SECTOR_SIZE.
+WOLFBOOT_SECTOR_SIZE?=0x1000
+
+# 128KB flash, 16KB SRAM
+# 32KB bootloader, 44KB boot/update partitions, 4KB swap at last logical sector
+WOLFBOOT_PARTITION_SIZE?=0xB000
+WOLFBOOT_PARTITION_BOOT_ADDRESS?=0x8000
+WOLFBOOT_PARTITION_UPDATE_ADDRESS?=0x13000
+WOLFBOOT_PARTITION_SWAP_ADDRESS?=0x1F000

hal/kinetis_kl26.c

@@ -37,6 +37,7 @@ int  uart_tx(const uint8_t c);
 int  uart_rx(uint8_t *c);
 #ifdef DEBUG_UART
 void uart_write(const char *buf, unsigned int len);
+void uart_printf(const char *fmt, ...);
 #endif
 
 #ifndef NVM_FLASH_WRITEONCE
@@ -114,8 +115,40 @@ static const osc_config_t oscConfig_BOARD_BootClockRUN = {
 
 static void do_flash_init(void);
 
+/* Stack high-water-mark instrumentation. Paints the unused stack region with
+ * a sentinel at hal_init entry and reports the high-water mark just before
+ * jumping to the application. */
+extern uint32_t _end_bss;
+extern uint32_t END_STACK;
+#define STACK_FILL 0xA5A5A5A5UL
+
+static void paint_stack(void)
+{
+    register uint32_t sp;
+    uint32_t *p;
+    __asm__ volatile("mov %0, sp" : "=r"(sp));
+    /* Leave a 64-byte safety margin so we don't overwrite our own frame. */
+    sp -= 64U;
+    for (p = &_end_bss; (uint32_t)p < sp; p++)
+        *p = STACK_FILL;
+}
+
+static uint32_t stack_used(void)
+{
+    uint32_t *p;
+    for (p = &_end_bss; p < &END_STACK; p++) {
+        if (*p != STACK_FILL)
+            break;
+    }
+    return (uint32_t)&END_STACK - (uint32_t)p;
+}
+
 void hal_init(void)
 {
+    /* Paint stack BEFORE anything else so the watermark covers the entire
+     * boot path. */
+    paint_stack();
+
     /* Disable the COP watchdog */
     *((volatile uint32_t *)0x40048100) = 0;
 
@@ -140,6 +173,10 @@ void hal_init(void)
 
 void hal_prepare_boot(void)
 {
+#ifdef DEBUG_UART
+    uart_printf("stack high-water: %u bytes\r\n",
+                (unsigned)stack_used());
+#endif
 }
 
 #endif /* __WOLFBOOT */