mirror of https://gitee.com/openkylin/qemu.git
65 lines
1.6 KiB
C
65 lines
1.6 KiB
C
|
/*
|
||
|
|
* MIPS o32 Linux syscall example
|
||
|
|
*
|
||
|
|
* http://www.linux-mips.org/wiki/RISC/os
|
||
|
|
* http://www.linux-mips.org/wiki/MIPSABIHistory
|
||
|
|
* http://www.linux.com/howtos/Assembly-HOWTO/mips.shtml
|
||
|
|
*
|
||
|
|
* mipsel-linux-gcc -nostdlib -mno-abicalls -fno-PIC -mabi=32 \
|
||
|
|
* -O2 -static -o hello-mips hello-mips.c
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
#define __NR_SYSCALL_BASE 4000
|
||
|
|
#define __NR_exit (__NR_SYSCALL_BASE+ 1)
|
||
|
|
#define __NR_write (__NR_SYSCALL_BASE+ 4)
|
||
|
|
|
||
|
|
static inline void exit1(int status)
|
||
|
|
{
|
||
|
|
register unsigned long __a0 asm("$4") = (unsigned long) status;
|
||
|
|
|
||
|
|
__asm__ __volatile__ (
|
||
|
|
" .set push \n"
|
||
|
|
" .set noreorder \n"
|
||
|
|
" li $2, %0 \n"
|
||
|
|
" syscall \n"
|
||
|
|
" .set pop "
|
||
|
|
:
|
||
|
|
: "i" (__NR_exit), "r" (__a0)
|
||
|
|
: "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
|
||
|
|
"memory");
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int write(int fd, const char *buf, int len)
|
||
|
|
{
|
||
|
|
register unsigned long __a0 asm("$4") = (unsigned long) fd;
|
||
|
|
register unsigned long __a1 asm("$5") = (unsigned long) buf;
|
||
|
|
register unsigned long __a2 asm("$6") = (unsigned long) len;
|
||
|
|
register unsigned long __a3 asm("$7");
|
||
|
|
unsigned long __v0;
|
||
|
|
|
||
|
|
__asm__ __volatile__ (
|
||
|
|
" .set push \n"
|
||
|
|
" .set noreorder \n"
|
||
|
|
" li $2, %2 \n"
|
||
|
|
" syscall \n"
|
||
|
|
" move %0, $2 \n"
|
||
|
|
" .set pop "
|
||
|
|
: "=r" (__v0), "=r" (__a3)
|
||
|
|
: "i" (__NR_write), "r" (__a0), "r" (__a1), "r" (__a2)
|
||
|
|
: "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
|
||
|
|
"memory");
|
||
|
|
|
||
|
|
/* if (__a3 == 0) */
|
||
|
|
return (int) __v0;
|
||
|
|
/*
|
||
|
|
errno = __v0;
|
||
|
|
return -1;
|
||
|
|
*/
|
||
|
|
}
|
||
|
|
|
||
|
|
void __start(void)
|
||
|
|
{
|
||
|
|
write (1, "Hello, World!\n", 14);
|
||
|
|
exit1 (42);
|
||
|
|
}
|