ths | e463004 | 2006-12-14 14:48:11 +0000 | [diff] [blame] | 1 | /* |
| 2 | * MIPS o32 Linux syscall example |
| 3 | * |
| 4 | * http://www.linux-mips.org/wiki/RISC/os |
| 5 | * http://www.linux-mips.org/wiki/MIPSABIHistory |
| 6 | * http://www.linux.com/howtos/Assembly-HOWTO/mips.shtml |
| 7 | * |
| 8 | * mipsel-linux-gcc -nostdlib -mno-abicalls -fno-PIC -mabi=32 \ |
| 9 | * -O2 -static -o hello-mips hello-mips.c |
| 10 | * |
| 11 | */ |
| 12 | #define __NR_SYSCALL_BASE 4000 |
| 13 | #define __NR_exit (__NR_SYSCALL_BASE+ 1) |
| 14 | #define __NR_write (__NR_SYSCALL_BASE+ 4) |
| 15 | |
| 16 | static inline void exit1(int status) |
| 17 | { |
| 18 | register unsigned long __a0 asm("$4") = (unsigned long) status; |
| 19 | |
| 20 | __asm__ __volatile__ ( |
| 21 | " .set push \n" |
| 22 | " .set noreorder \n" |
| 23 | " li $2, %0 \n" |
| 24 | " syscall \n" |
| 25 | " .set pop " |
| 26 | : |
| 27 | : "i" (__NR_exit), "r" (__a0) |
| 28 | : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24", |
| 29 | "memory"); |
| 30 | } |
| 31 | |
| 32 | static inline int write(int fd, const char *buf, int len) |
| 33 | { |
| 34 | register unsigned long __a0 asm("$4") = (unsigned long) fd; |
| 35 | register unsigned long __a1 asm("$5") = (unsigned long) buf; |
| 36 | register unsigned long __a2 asm("$6") = (unsigned long) len; |
| 37 | register unsigned long __a3 asm("$7"); |
| 38 | unsigned long __v0; |
| 39 | |
| 40 | __asm__ __volatile__ ( |
| 41 | " .set push \n" |
| 42 | " .set noreorder \n" |
| 43 | " li $2, %2 \n" |
| 44 | " syscall \n" |
| 45 | " move %0, $2 \n" |
| 46 | " .set pop " |
| 47 | : "=r" (__v0), "=r" (__a3) |
| 48 | : "i" (__NR_write), "r" (__a0), "r" (__a1), "r" (__a2) |
| 49 | : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24", |
| 50 | "memory"); |
| 51 | |
| 52 | /* if (__a3 == 0) */ |
| 53 | return (int) __v0; |
| 54 | /* |
| 55 | errno = __v0; |
| 56 | return -1; |
| 57 | */ |
| 58 | } |
| 59 | |
| 60 | void __start(void) |
| 61 | { |
| 62 | write (1, "Hello, World!\n", 14); |
| 63 | exit1 (42); |
| 64 | } |