openocd/testing/examples/ledtest-imx27ads/crt0.S

47 lines
1015 B
ArmAsm

/* Sample initialization file */
.extern main
.extern exit
/* .text is used instead of .section .text so it works with arm-aout too. */
.text
.code 32
.align 0
.global _mainCRTStartup
.global _start
.global start
start:
_start:
_mainCRTStartup:
/* Start by setting up a stack */
/* Set up the stack pointer to end of bss */
ldr r3, .LC2
mov sp, r3
sub sl, sp, #512 /* Still assumes 512 bytes below sl */
mov a2, #0 /* Second arg: fill value */
mov fp, a2 /* Null frame pointer */
mov r7, a2 /* Null frame pointer for Thumb */
ldr a1, .LC1 /* First arg: start of memory block */
ldr a3, .LC2 /* Second arg: end of memory block */
sub a3, a3, a1 /* Third arg: length of block */
mov r0, #0 /* no arguments */
mov r1, #0 /* no argv either */
bl main
bl exit /* Should not return */
/* For Thumb, constants must be after the code since only
positive offsets are supported for PC relative addresses. */
.align 0
.LC1:
.word __bss_start__
.LC2:
.word __bss_end__