tools/nolibc: loongarch: 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>
This commit is contained in:
Zhangjin Wu 2023-07-16 02:30:02 +08:00 committed by Willy Tarreau
parent 431b806b9b
commit 61bd4621c0

View File

@ -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();
}