diff options
Diffstat (limited to 'tools/include/nolibc/arch-x86_64.h')
| -rw-r--r-- | tools/include/nolibc/arch-x86_64.h | 52 |
1 files changed, 26 insertions, 26 deletions
diff --git a/tools/include/nolibc/arch-x86_64.h b/tools/include/nolibc/arch-x86_64.h index 0e1e9eb8545d..17f6751208e7 100644 --- a/tools/include/nolibc/arch-x86_64.h +++ b/tools/include/nolibc/arch-x86_64.h @@ -7,18 +7,6 @@ #ifndef _NOLIBC_ARCH_X86_64_H #define _NOLIBC_ARCH_X86_64_H -/* O_* macros for fcntl/open are architecture-specific */ -#define O_RDONLY 0 -#define O_WRONLY 1 -#define O_RDWR 2 -#define O_CREAT 0x40 -#define O_EXCL 0x80 -#define O_NOCTTY 0x100 -#define O_TRUNC 0x200 -#define O_APPEND 0x400 -#define O_NONBLOCK 0x800 -#define O_DIRECTORY 0x10000 - /* The struct returned by the stat() syscall, equivalent to stat64(). The * syscall returns 116 bytes and stops in the middle of __unused. */ @@ -190,6 +178,9 @@ struct sys_stat_struct { _ret; \ }) +char **environ __attribute__((weak)); +const unsigned long *_auxv __attribute__((weak)); + /* startup code */ /* * x86-64 System V ABI mandates: @@ -197,19 +188,28 @@ struct sys_stat_struct { * 2) The deepest stack frame should be zero (the %rbp). * */ -__asm__ (".section .text\n" - ".weak _start\n" - "_start:\n" - "pop %rdi\n" // argc (first arg, %rdi) - "mov %rsp, %rsi\n" // argv[] (second arg, %rsi) - "lea 8(%rsi,%rdi,8),%rdx\n" // then a NULL then envp (third arg, %rdx) - "xor %ebp, %ebp\n" // zero the stack frame - "and $-16, %rsp\n" // x86 ABI : esp must be 16-byte aligned before call - "call main\n" // main() returns the status code, we'll exit with it. - "mov %eax, %edi\n" // retrieve exit code (32 bit) - "mov $60, %eax\n" // NR_exit == 60 - "syscall\n" // really exit - "hlt\n" // ensure it does not return - ""); +void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void) +{ + __asm__ volatile ( + "pop %rdi\n" // argc (first arg, %rdi) + "mov %rsp, %rsi\n" // argv[] (second arg, %rsi) + "lea 8(%rsi,%rdi,8),%rdx\n" // then a NULL then envp (third arg, %rdx) + "mov %rdx, environ\n" // save environ + "xor %ebp, %ebp\n" // zero the stack frame + "mov %rdx, %rax\n" // search for auxv (follows NULL after last env) + "0:\n" + "add $8, %rax\n" // search for auxv using rax, it follows the + "cmp -8(%rax), %rbp\n" // ... NULL after last env (rbp is zero here) + "jnz 0b\n" + "mov %rax, _auxv\n" // save it into _auxv + "and $-16, %rsp\n" // x86 ABI : esp must be 16-byte aligned before call + "call main\n" // main() returns the status code, we'll exit with it. + "mov %eax, %edi\n" // retrieve exit code (32 bit) + "mov $60, %eax\n" // NR_exit == 60 + "syscall\n" // really exit + "hlt\n" // ensure it does not return + ); + __builtin_unreachable(); +} #endif // _NOLIBC_ARCH_X86_64_H |