@@ -10,34 +10,10 @@
void __attribute__((weak, noreturn, optimize("omit-frame-pointer"))) __no_stack_protector _start(void)
{
__asm__ volatile (
- "lg %r2,0(%r15)\n" /* argument count */
- "la %r3,8(%r15)\n" /* argument pointers */
-
- "xgr %r0,%r0\n" /* r0 will be our NULL value */
- /* search for envp */
- "lgr %r4,%r3\n" /* start at argv */
- "0:\n"
- "clg %r0,0(%r4)\n" /* entry zero? */
- "la %r4,8(%r4)\n" /* advance pointer */
- "jnz 0b\n" /* no -> test next pointer */
- /* yes -> r4 now contains start of envp */
- "larl %r1,environ\n"
- "stg %r4,0(%r1)\n"
-
- /* search for auxv */
- "lgr %r5,%r4\n" /* start at envp */
- "1:\n"
- "clg %r0,0(%r5)\n" /* entry zero? */
- "la %r5,8(%r5)\n" /* advance pointer */
- "jnz 1b\n" /* no -> test next pointer */
- "larl %r1,_auxv\n" /* yes -> store value in _auxv */
- "stg %r5,0(%r1)\n"
-
- "aghi %r15,-160\n" /* allocate new stackframe */
- "xc 0(8,%r15),0(%r15)\n" /* clear backchain */
- "brasl %r14,main\n" /* ret value of main is arg to exit */
- "lghi %r1,1\n" /* __NR_exit */
- "svc 0\n"
+ "lgr %r2, %r15\n" /* save stack pointer to %r2, as arg1 of _start_c */
+ "aghi %r15, -160\n" /* allocate new stackframe */
+ "xc 0(8,%r15), 0(%r15)\n" /* clear backchain */
+ "brasl %r14, _start_c\n" /* transfer to c runtime */
);
__builtin_unreachable();
}
move most of the _start operations to _start_c(). Signed-off-by: Zhangjin Wu <falcon@tinylab.org> --- tools/include/nolibc/s390/crt.h | 32 ++++---------------------------- 1 file changed, 4 insertions(+), 28 deletions(-)