| ; At present, nasm doesn't seem to support PIC generation for Mach-O. |
| ; The PIC support code below is a little tricky. |
| [extern func] |
| SECTION .rodata |
| const_base: |
| |
| %define GOTOFF(got,sym) (got) + (sym) - const_base |
| |
| %imacro get_GOT 1 |
| ; NOTE: this macro destroys ecx resister. |
| call %%geteip |
| add ecx, byte (%%ref - $) |
| jmp short %%adjust |
| %%geteip: |
| mov ecx, [esp] |
| ret |
| %%adjust: |
| push ebp |
| xor ebp,ebp ; ebp = 0 |
| %ifidni %1,ebx ; (%1 == ebx) |
| ; db 0x8D,0x9C + jmp near const_base = |
| ; lea ebx, [ecx+ebp*8+(const_base-%%ref)] ; 8D,9C,E9,(offset32) |
| db 0x8D,0x9C ; 8D,9C |
| jmp near const_base ; E9,(const_base-%%ref) |
| %%ref: |
| %else ; (%1 != ebx) |
| ; db 0x8D,0x8C + jmp near const_base = |
| ; lea ecx, [ecx+ebp*8+(const_base-%%ref)] ; 8D,8C,E9,(offset32) |
| db 0x8D,0x8C ; 8D,8C |
| jmp strict near const_base ; E9,(const_base-%%ref) |
| %%ref: mov %1, ecx |
| %endif ; (%1 == ebx) |
| pop ebp |
| %endmacro |
| |
| SECTION .text |
| |
| jmp const_base |
| |
| get_GOT ebx |
| |
| jmp const_base |
| |
| call func |
| |
| ret |
