.versions SH4 mova r0, [first_patch_header] mov r7, r0 # r7 = read ptr xor r3, r3 dec r3 shl r3, 2 # r3 = 0xFFFFFFFC (mask for aligning r7) apply_patch: add r7, 3 and r7, r3 # r7 = (r7 + 3) & (~3) (align to 4-byte boundary) mov.l r4, [r7]+ # r4 = dest addr mov.l r5, [r7]+ add r5, r4 # r5 = dest end ptr (dest addr + size) cmpeq r4, r5 # if (size == 0) return bt done again: cmpeq r4, r5 bt apply_patch # if (r4 == r5) done with the patch; go to next header mov.b r0, [r7]+ mov.b [r4], r0 # *(r4) = *(r7++); bs again # r4++; continue add r4, 1 done: rets nop .align 4 first_patch_header: .versions PPC mflr r8 b get_patch_data_ptr get_patch_data_ptr_ret: mflr r7 # r7 = patch header apply_patch: addi r4, r7, 8 # r4 = start of patch data lwz r3, [r4 - 8] # r3 = patch dest address lwz r5, [r4 - 4] # r5 = patch data size or r0, r3, r5 cmplwi r0, 0 mtlr r8 beqlr add r7, r4, r5 # r7 = next patch header .include CopyCode b apply_patch get_patch_data_ptr: bl get_patch_data_ptr_ret first_patch_header: .versions 4OJB 4OJD 4OJU 4OED 4OEU 4OPD 4OPU start: .include GetVersionInfoXB test eax, eax jnz can_patch ret can_patch: push esi push edi push ebx mov edi, eax # edi = ptr to version info struct jmp get_patch_data_ptr get_patch_data_ptr_ret: pop ebx # ebx = patch header apply_next_patch: cmp dword [ebx + 4], 0 jne copy_code_and_apply_again pop ebx pop edi pop esi mov eax, 1 ret copy_code_and_apply_again: push dword [ebx] # dest addr mov ecx, [edi + 0x0C] call [ecx] # MmQueryAddressProtect mov esi, eax # esi = prev protection flags push 4 # new protection flags push dword [ebx + 4] # size push dword [ebx] # base address mov ecx, [edi + 0x08] call [ecx] # MmSetAddressProtect xor ecx, ecx # ecx = offset mov edx, [ebx] # edx = dest addr copy_next_byte: mov al, [ebx + ecx + 8] # copy one byte to dest mov [edx + ecx], al inc ecx # offset++ cmp [ebx + 4], ecx # check if all bytes have been copied jne copy_next_byte push esi # new protection flags push dword [ebx + 4] # size push dword [ebx] # base address lea ebx, [ebx + ecx + 8] # advance to next block mov ecx, [edi + 0x08] call [ecx] # MmSetAddressProtect jmp apply_next_patch get_patch_data_ptr: call get_patch_data_ptr_ret first_patch_header: .versions 2OJW 2OJZ 59NJ 59NL start: push ebx jmp get_patch_data_ptr get_patch_data_ptr_ret: pop ebx # ebx = patch header apply_next_patch: cmp dword [ebx + 4], 0 jne copy_code_and_apply_again pop ebx mov eax, 1 ret copy_code_and_apply_again: xor ecx, ecx # ecx = offset mov edx, [ebx] # edx = dest addr copy_next_byte: mov al, [ebx + ecx + 8] # copy one byte to dest mov [edx + ecx], al inc ecx # offset++ cmp [ebx + 4], ecx # check if all bytes have been copied jne copy_next_byte lea ebx, [ebx + ecx + 8] # advance to next block jmp apply_next_patch get_patch_data_ptr: call get_patch_data_ptr_ret first_patch_header: