Let's move most of the _start operations to _start_c().
Signed-off-by: Zhangjin Wu falcon@tinylab.org --- tools/include/nolibc/arch-aarch64.h | 25 ++++--------------------- 1 file changed, 4 insertions(+), 21 deletions(-)
diff --git a/tools/include/nolibc/arch-aarch64.h b/tools/include/nolibc/arch-aarch64.h index 4a8a6f386865..ef98a751783f 100644 --- a/tools/include/nolibc/arch-aarch64.h +++ b/tools/include/nolibc/arch-aarch64.h @@ -143,33 +143,16 @@ _arg1; \ })
-char **environ __attribute__((weak)); -const unsigned long *_auxv __attribute__((weak)); - /* startup code */ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __no_stack_protector _start(void) { __asm__ volatile ( #ifdef _NOLIBC_STACKPROTECTOR - "bl __stack_chk_init\n" /* initialize stack protector */ + "bl __stack_chk_init\n" /* initialize stack protector */ #endif - "ldr x0, [sp]\n" /* argc (x0) was in the stack */ - "add x1, sp, 8\n" /* argv (x1) = sp */ - "lsl x2, x0, 3\n" /* envp (x2) = 8*argc ... */ - "add x2, x2, 8\n" /* + 8 (skip null) */ - "add x2, x2, x1\n" /* + argv */ - "adrp x3, environ\n" /* x3 = &environ (high bits) */ - "str x2, [x3, #:lo12:environ]\n" /* store envp into environ */ - "mov x4, x2\n" /* search for auxv (follows NULL after last env) */ - "0:\n" - "ldr x5, [x4], 8\n" /* x5 = *x4; x4 += 8 */ - "cbnz x5, 0b\n" /* and stop at NULL after last env */ - "adrp x3, _auxv\n" /* x3 = &_auxv (high bits) */ - "str x4, [x3, #:lo12:_auxv]\n" /* store x4 into _auxv */ - "and sp, x1, -16\n" /* sp must be 16-byte aligned in the callee */ - "bl main\n" /* main() returns the status code, we'll exit with it. */ - "mov x8, 93\n" /* NR_exit == 93 */ - "svc #0\n" + "mov x0, sp\n" /* save stack pointer to x0, as arg1 of _start_c*/ + "and sp, x0, -16\n" /* sp must be 16-byte aligned in the callee */ + "bl _start_c\n" /* transfer to c runtime */ ); __builtin_unreachable(); }