Commit 61bd4621 authored by Zhangjin Wu's avatar Zhangjin Wu Committed by Willy Tarreau
Browse files

tools/nolibc: loongarch: shrink _start with _start_c 



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

Signed-off-by: default avatarZhangjin Wu <falcon@tinylab.org>
Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
parent 431b806b

tools/include/nolibc/arch-loongarch.h

+4 −40
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#define _NOLIBC_ARCH_LOONGARCH_H



#include "compiler.h"

#include "crt.h"



/* Syscalls for LoongArch :

 *   - stack is 16-byte aligned
@@ -143,26 +144,9 @@ 
	_arg1;                                                                \

})



char **environ __attribute__((weak));

const unsigned long *_auxv __attribute__((weak));



#if __loongarch_grlen == 32

#define LONGLOG      "2"

#define SZREG        "4"

#define REG_L        "ld.w"

#define LONG_S       "st.w"

#define LONG_ADD     "add.w"

#define LONG_ADDI    "addi.w"

#define LONG_SLL     "slli.w"

#define LONG_BSTRINS "bstrins.w"

#else /* __loongarch_grlen == 64 */

#define LONGLOG      "3"

#define SZREG        "8"

#define REG_L        "ld.d"

#define LONG_S       "st.d"

#define LONG_ADD     "add.d"

#define LONG_ADDI    "addi.d"

#define LONG_SLL     "slli.d"

#define LONG_BSTRINS "bstrins.d"

#endif
@@ -170,29 +154,9 @@ 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

		"bl __stack_chk_init\n"               /* initialize stack protector                          */

#endif

		REG_L        " $a0, $sp, 0\n"         /* argc (a0) was in the stack                          */

		LONG_ADDI    " $a1, $sp, "SZREG"\n"   /* argv (a1) = sp + SZREG                              */

		LONG_SLL     " $a2, $a0, "LONGLOG"\n" /* envp (a2) = SZREG*argc ...                          */

		LONG_ADDI    " $a2, $a2, "SZREG"\n"   /*             + SZREG (skip null)                     */

		LONG_ADD     " $a2, $a2, $a1\n"       /*             + argv                                  */



		"move          $a3, $a2\n"            /* iterate a3 over envp to find auxv (after NULL)      */

		"0:\n"                                /* do {                                                */

		REG_L        " $a4, $a3, 0\n"         /*   a4 = *a3;                                         */

		LONG_ADDI    " $a3, $a3, "SZREG"\n"   /*   a3 += sizeof(void*);                              */

		"bne           $a4, $zero, 0b\n"      /* } while (a4);                                       */

		"la.pcrel      $a4, _auxv\n"          /* a4 = &_auxv                                         */

		LONG_S       " $a3, $a4, 0\n"         /* store a3 into _auxv                                 */



		"la.pcrel      $a3, environ\n"        /* a3 = &environ                                       */

		LONG_S       " $a2, $a3, 0\n"         /* store envp(a2) into environ                         */

		LONG_BSTRINS " $sp, $zero, 3, 0\n"    /* sp must be 16-byte aligned                          */

		"bl            main\n"                /* main() returns the status code, we'll exit with it. */

		"li.w          $a7, 93\n"             /* NR_exit == 93                                       */

		"syscall       0\n"

		"move          $a0, $sp\n"         /* save stack pointer to $a0, as arg1 of _start_c */

		LONG_BSTRINS " $sp, $zero, 3, 0\n" /* $sp must be 16-byte aligned                    */

		"bl            _start_c\n"         /* transfer to c runtime                          */

	);

	__builtin_unreachable();

}