ref: bec29fb78c83ad0fd51a22bf1fda6306a8f3934b
dir: /syscall-osx.s/
.globl _std$syscall
_std$syscall:
popl %ecx /* return address */
popl %eax /* call num */
pushl %ecx
int $0x80
pushl %ecx /* put the return address back */
ret