tools/nolibc: i386: shrink _start with _start_c

move most of the _start operations to _start_c(), include the
stackprotector initialization.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/tools/include/nolibc/arch-i386.h b/tools/include/nolibc/arch-i386.h
index fe0b73f032c3ae55734912316addac7627c29249..64415b9fac77f9960e2e643ae69789f23b3f890b 100644 (file)
--- 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();
 }