for(;;){ run next instruction }
enum { Data = 0x378+0 Status = 0x378+1, Notbusy = 0x80, Ctl = 0x378+2, Strobe = 0x01, }; lptputc(c) { while((inb(Status)&Notbusy) == 0) ; outb(Data, c) outb(Ctl, Strobe) outb(Ctl, 0) }
at&t | "C" |
movl %eax, %edx | |
movl $0x123, %edx | |
movl (%ebx), %edx | edx = mem[ebx]; |
movl 4(%ebx), %edx | edx = mem[ebx+4]; |
movl 0x123, %edx | edx = mem[0x123]; |
subl $4, %esp movl %eax, (%esp)
movl (%esp), %eax addl $4, %esp
pushl %eip movl $0x12345, %eip
popl %eip
+------------+ | arg 2 | +------------+ | arg 1 | +------------+ | ret %eip | +============+ %ebp-> | saved %ebp | +------------+ | | | | | | | | | | %esp-> | | +------------+
pushl %ebp movl %esp, %ebp
movl %ebp, %esp popl %ebpor
leave
int main(void) { return f(8)+1; } int f(int x) { return g(x); } int g(int x) { return x+3; }
_main: prologue pushl %ebp movl %esp, %ebp body pushl $8 call _f addl $1, %eax epilogue movl %ebp, %esp popl %ebp ret _f: prologue pushl %ebp movl %esp, %ebp body pushl 8(%esp) call _g epilogue movl %ebp, %esp popl %ebp ret _g: prologue pushl %ebp movl %esp, %ebp save %ebx pushl %ebx body movl 8(%ebp), %ebx addl $3, %ebx movl %ebx, %eax restore %ebx popl %ebx epilogue movl %ebp, %esp popl %ebp ret
_g: movl 4(%esp), %eax addl $3, %eax ret