soc: st: stm32: add common kconfig symbols for kernel stack size

Provide default values for common kconfig symbols for main, idle and
isr stack sizes, which apply on all STM32 MCU families with low RAM
memory(less than 8 KiB).
These kconfig symbols help reduce kernel sizes to fit within
limited RAM.

Signed-off-by: Fabrice DJIATSA <[email protected]>

Author: djiatsaf-st

soc/st/stm32/Kconfig.defconfig

@@ -20,6 +20,21 @@ config CLOCK_CONTROL
 config CORTEX_M_SYSTICK
 	default n if STM32_LPTIM_TIMER
 
+# Reduce kernel stack sizes to fit MCUs with 8 KiB RAM or less
+config MAIN_STACK_SIZE
+	default 320 if SRAM_SIZE <= 2
+	default 512 if SRAM_SIZE <= 4
+	default 640 if SRAM_SIZE <= 8
+
+config IDLE_STACK_SIZE
+	default 100 if SRAM_SIZE <= 2
+	default 150 if SRAM_SIZE <= 4
+	default 200 if SRAM_SIZE <= 8
+
+config ISR_STACK_SIZE
+	default 256 if SRAM_SIZE <= 2
+	default 512 if SRAM_SIZE <= 8
+
 DT_STM32_RCC_PATH := $(dt_nodelabel_path,rcc)
 DT_STM32_RCC_CLOCK_FREQ := $(dt_node_int_prop_int,$(DT_STM32_RCC_PATH),clock-frequency)