move most of the _start operations to _start_c(), include the
stackprotector initialization.
Signed-off-by: Zhangjin Wu <falcon@xxxxxxxxxxx>
---
tools/include/nolibc/arch-i386.h | 34 +++++++-------------------------
1 file changed, 7 insertions(+), 27 deletions(-)
diff --git a/tools/include/nolibc/arch-i386.h b/tools/include/nolibc/arch-i386.h
index fe0b73f032c3..64415b9fac77 100644
--- a/tools/include/nolibc/arch-i386.h
+++ b/tools/include/nolibc/arch-i386.h
@@ -8,6 +8,7 @@
#define _NOLIBC_ARCH_I386_H
#include "compiler.h"
+#include "crt.h"
/* Syscalls for i386 :
* - mostly similar to x86_64
@@ -154,9 +155,6 @@
_eax; \
})
-char **environ __attribute__((weak));
-const unsigned long *_auxv __attribute__((weak));
-
/* startup code */
/*
* i386 System V ABI mandates:
@@ -167,30 +165,12 @@ const unsigned long *_auxv __attribute__((weak));
void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
{
__asm__ volatile (
-#ifdef _NOLIBC_STACKPROTECTOR
- "call __stack_chk_init\n" /* initialize stack protector */
-#endif
- "pop %eax\n" /* argc (first arg, %eax) */
- "mov %esp, %ebx\n" /* argv[] (second arg, %ebx) */
- "lea 4(%ebx,%eax,4),%ecx\n" /* then a NULL then envp (third arg, %ecx) */
- "mov %ecx, environ\n" /* save environ */
- "xor %ebp, %ebp\n" /* zero the stack frame */
- "mov %ecx, %edx\n" /* search for auxv (follows NULL after last env) */
- "0:\n"
- "add $4, %edx\n" /* search for auxv using edx, it follows the */
- "cmp -4(%edx), %ebp\n" /* ... NULL after last env (ebp is zero here) */
- "jnz 0b\n"
- "mov %edx, _auxv\n" /* save it into _auxv */
- "and $-16, %esp\n" /* x86 ABI : esp must be 16-byte aligned before */
- "sub $4, %esp\n" /* the call instruction (args are aligned) */
- "push %ecx\n" /* push all registers on the stack so that we */
- "push %ebx\n" /* support both regparm and plain stack modes */
- "push %eax\n"
- "call main\n" /* main() returns the status code in %eax */
- "mov %eax, %ebx\n" /* retrieve exit code (32-bit int) */
- "movl $1, %eax\n" /* NR_exit == 1 */
- "int $0x80\n" /* exit now */
- "hlt\n" /* ensure it does not */
+ "xor %ebp, %ebp\n" /* zero the stack frame */
+ "mov %esp, %eax\n" /* save stack pointer to %eax, as arg1 of _start_c */
+ "and $-16, %esp\n" /* last pushed argument must be 16-byte aligned */
+ "push %eax\n" /* push arg1 on stack to support plain stack modes too */
+ "call _start_c\n" /* transfer to c runtime */
+ "hlt\n" /* ensure it does not return */
);
__builtin_unreachable();
}
--
2.25.1
