move most of the _start operations to _start_c().
Signed-off-by: Zhangjin Wu falcon@tinylab.org --- tools/include/nolibc/arch-i386.h | 33 ++++++++------------------------ 1 file changed, 8 insertions(+), 25 deletions(-)
diff --git a/tools/include/nolibc/arch-i386.h b/tools/include/nolibc/arch-i386.h index 1d4b683bc2cd..f0d0f5c364b8 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: @@ -168,29 +166,14 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __no_stack_pr { __asm__ volatile ( #ifdef _NOLIBC_STACKPROTECTOR - "call __stack_chk_init\n" /* initialize stack protector */ + "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(); }