| 1 | /* |
| 2 | * Non-libc syscall hello world for Aarch64 BE |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-or-later |
| 5 | */ |
| 6 | |
| 7 | #define __NR_write 64 |
| 8 | #define __NR_exit 93 |
| 9 | |
| 10 | int write(int fd, char *buf, int len) |
| 11 | { |
| 12 | register int x0 __asm__("x0") = fd; |
| 13 | register char *x1 __asm__("x1") = buf; |
| 14 | register int x2 __asm__("x2") = len; |
| 15 | register int x8 __asm__("x8") = __NR_write; |
| 16 | |
| 17 | asm volatile("svc #0" : : "r"(x0), "r"(x1), "r"(x2), "r"(x8)); |
| 18 | |
| 19 | return len; |
| 20 | } |
| 21 | |
| 22 | void exit(int ret) |
| 23 | { |
| 24 | register int x0 __asm__("x0") = ret; |
| 25 | register int x8 __asm__("x8") = __NR_exit; |
| 26 | |
| 27 | asm volatile("svc #0" : : "r"(x0), "r"(x8)); |
| 28 | __builtin_unreachable(); |
| 29 | } |
| 30 | |
| 31 | void _start(void) |
| 32 | { |
| 33 | write(1, "Hello World\n", 12); |
| 34 | exit(0); |
| 35 | } |