add missing xbox includes

2025-06-16 19:22:38 -07:00
parent e24a0e3c40
commit 923cc4ebb0
2 changed files with 202 additions and 0 deletions
@@ -0,0 +1,101 @@
+# This function has the same signature as WriteCallToCodeMulti-59NL.
+
+write_call_to_code:
+  .include  GetVersionInfoXB
+  push      ebx
+  push      ebp
+  push      esi
+  push      edi
+  mov       edi, eax
+
+  # [esp + 0x14] = code ptr
+  # [esp + 0x18] = code size
+  # [esp + 0x1C] = callsite count
+  # [esp + 0x20] = callsite address
+  # [esp + 0x24] = callsite size
+  # ... (further callsite address/size pairs)
+  # esi = allocated code addr
+  # edi = version_info
+
+  # Allocate memory for the copied code
+  mov       ecx, [esp + 0x18]
+  mov       edx, [edi + 0x14]
+  mov       edx, [edx]
+  call      [edi + 0x10]  # malloc7(code_size, version_info->malloc7_instance)
+  test      eax, eax
+  je        done
+  mov       esi, eax
+
+  # Copy the code to the newly-allocated memory
+  # eax = dest pointer (from malloc7 call above)
+  mov       edx, [esp + 0x14]  # edx = source pointer
+  mov       ecx, [esp + 0x18]  # ecx = source size
+memcpy_again:
+  dec       ecx
+  mov       bl, [edx + ecx]  # Copy one byte from source to dest
+  mov       [esi + ecx], bl
+  test      ecx, ecx
+  jne       memcpy_again
+
+  # Make the memory executable
+  push      0x40
+  push      dword [esp + 0x1C]
+  push      esi
+  mov       ecx, [edi + 0x08]
+  call      [ecx] # MmSetAddressProtect(dest_addr, code_size, XBOX_PAGE_EXECUTE_READWRITE)
+
+  # Write the call opcodes
+  mov       ebx, [esp + 0x1C]  # ebx = callsite count
+  mov       ebp, 0x20  # Stack offset of first callsite pair
+
+next_callsite:
+  # Make the memory writable
+  push      esi
+  mov       ecx, [edi + 0x0C]
+  call      [ecx]  # MmQueryAddressProtect(callsite_addr)
+  push      eax
+
+  push      0x04
+  push      dword [esp + ebp + 0x0C]
+  push      dword [esp + ebp + 0x0C]
+  mov       ecx, [edi + 0x08]
+  call      [ecx]  # MmSetAddressProtect(callsite_addr, callsite_size, XBOX_PAGE_READWRITE)
+
+  mov       edx, [esp + ebp + 4]  # edx = jump callsite
+  lea       ecx, [esi - 5]
+  sub       ecx, edx  # ecx = (dest code addr) - (jump callsite) - 5
+  mov       byte [edx], 0xE8
+  mov       [edx + 1], ecx  # Write E8 (call) followed by delta
+
+  # Write as many nops after the call opcode as necessary
+  mov       ecx, 5
+  mov       eax, [esp + ebp + 8]
+write_nop_again:
+  cmp       ecx, eax
+  jge       this_callsite_done
+  mov       byte [edx + ecx], 0x90
+  inc       ecx
+  jmp       write_nop_again
+
+this_callsite_done:
+  # Restore the previous protection
+  # Previous protection is still on the stack from MmQueryAddressProtect call
+  push      dword [esp + ebp + 8]
+  push      dword [esp + ebp + 8]
+  mov       ecx, [edi + 0x08]
+  call      [ecx]  # MmSetAddressProtect(callsite_addr, callsite_size, prev_protection)
+
+  add       ebp, 8
+  dec       ebx
+  jnz       next_callsite
+
+  mov       ecx, ebp
+
+done:
+  mov       edi, [esp]
+  mov       esi, [esp + 0x04]
+  mov       ebp, [esp + 0x08]
+  mov       ebx, [esp + 0x0C]
+  mov       eax, [esp + 0x10]
+  add       esp, ecx
+  jmp       eax