move most of the _start operations to _start_c().
Signed-off-by: Zhangjin Wu <falcon@xxxxxxxxxxx>
---
tools/include/nolibc/arch-s390.h | 36 +++++---------------------------
1 file changed, 5 insertions(+), 31 deletions(-)
diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
index a40424ba043e..051f3f4ed19b 100644
--- a/tools/include/nolibc/arch-s390.h
+++ b/tools/include/nolibc/arch-s390.h
@@ -9,6 +9,7 @@
#include <asm/unistd.h>
#include "compiler.h"
+#include "crt.h"
/* Syscalls for s390:
* - registers are 64-bit
@@ -137,41 +138,14 @@
_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 (
- "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();
}
--
2.25.1
