U-Boot 移植：栈顶的设置

栈顶的设置处于：arch/arm/lib/crt0.S。

/*
 * entry point of crt0 sequence
 */

ENTRY(_main)

/*
 * Set up initial C runtime environment and call board_init_f(0).
 */

#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK)
@       ldr     sp, =(CONFIG_SPL_STACK)
#else
@       ldr     sp, =(CONFIG_SYS_INIT_SP_ADDR)
#endif
        bic     sp, sp, #7      /* 8-byte alignment for ABI compliance */
        mov     r2, sp
        sub     sp, sp, #GD_SIZE        /* allocate one GD above SP */
        bic     sp, sp, #7      /* 8-byte alignment for ABI compliance */
        mov     r9, sp          /* GD is above SP */
        mov     r1, sp
        mov     r0, #0

栈顶的实际定义一般存在于：/home/du/u-boot/include/configs/xxboardxx.h。

/*
 * Initial stack pointer: 4k - GENERATED_GBL_DATA_SIZE in internal SRAM,
 * leaving the correct space for initial global data structure above
 * that address while providing maximum stack area below.
 */
#ifdef 0
# define CONFIG_SYS_INIT_SP_ADDR \
        (ATMEL_BASE_SRAM + 0x1000 - GENERATED_GBL_DATA_SIZE)
//#else
# define CONFIG_SYS_INIT_SP_ADDR \
        (ATMEL_BASE_SRAM1 + 0x1000 - GENERATED_GBL_DATA_SIZE)
#endif

#define CONFIG_SYS_INIT_SP_ADDR 0