| /* |
| * arch/m68k/syscall.S |
| * |
| * Common tail-handling code for system calls. |
| * |
| * The arguments are on the stack; the system call number in %d0. |
| */ |
| |
| .text |
| .align 2 |
| .globl __syscall_common |
| .type __syscall_common, @function |
| __syscall_common: |
| /* |
| * According to eglibc, separate moves are faster than movem; |
| * speed is important and this code is not duplicated anyway, |
| * so we do the same here. We use %a1 as scratch register for |
| * saving; syscall arguments are to be in %d1 to %d5 and %a0. |
| */ |
| move.l 24(%sp), %a0 /* orig.sp+24: arg 6 */ |
| move.l %d5, -(%sp) /* push d5 (callee saved) */ |
| move.l 24(%sp), %d5 /* orig.sp+20: arg 5 */ |
| move.l %d4, -(%sp) /* push d4 (callee saved) */ |
| move.l 24(%sp), %d4 /* orig.sp+16: arg 4 */ |
| move.l %d3, -(%sp) /* push d3 (callee saved) */ |
| move.l 24(%sp), %d3 /* orig.sp+12: arg 3 */ |
| move.l %d2, %a1 /* save d2 (callee saved) in a1 */ |
| move.l 20(%sp), %d2 /* orig.sp+8: arg 2 */ |
| move.l 16(%sp), %d1 /* orig.sp+4: arg 1 */ |
| trap #0 |
| move.l %a1, %d2 /* restore d2 from a1 (scratch) */ |
| move.l (%sp)+, %d3 /* pop d3..d5, see above */ |
| move.l (%sp)+, %d4 |
| move.l (%sp)+, %d5 |
| |
| /* syscall is done, result in %d0, registers are restored */ |
| .globl __syscall_checkandout |
| __syscall_checkandout: |
| /* now check for error */ |
| cmp.l #-4095, %d0 |
| bcs.l 1f /* jump if _not_ error */ |
| |
| /* prepare for error return */ |
| neg.l %d0 |
| move.l %d0, (errno) |
| move.l #-1, %d0 |
| /* fallthrough into common return path */ |
| |
| 1: /* copy return value to %a0 for syscalls returning pointers */ |
| move.l %d0, %a0 |
| rts |
| |
| .size __syscall_common,.-__syscall_common |
