xref: /openbmc/qemu/tests/tcg/mips/hello-mips.c (revision fc95c241)
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 }
65