/*
* Copyright (c) 2018 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
#include
#include "dmnt_cheat_types.hpp"
#include "dmnt_cheat_vm.hpp"
#include "dmnt_cheat_manager.hpp"
#include "dmnt_hid.hpp"
void DmntCheatVm::OpenDebugLogFile() {
#ifdef DMNT_CHEAT_VM_DEBUG_LOG
CloseDebugLogFile();
this->debug_log_file = fopen("cheat_vm_log.txt", "ab");
#endif
}
void DmntCheatVm::CloseDebugLogFile() {
#ifdef DMNT_CHEAT_VM_DEBUG_LOG
if (this->debug_log_file != NULL) {
fclose(this->debug_log_file);
this->debug_log_file = NULL;
}
#endif
}
void DmntCheatVm::LogToDebugFile(const char *format, ...) {
#ifdef DMNT_CHEAT_VM_DEBUG_LOG
if (this->debug_log_file != NULL) {
va_list arglist;
va_start(arglist, format);
vfprintf(this->debug_log_file, format, arglist);
va_end(arglist);
}
#endif
}
void DmntCheatVm::LogOpcode(const CheatVmOpcode *opcode) {
#ifndef DMNT_CHEAT_VM_DEBUG_LOG
return;
#endif
switch (opcode->opcode) {
case CheatVmOpcodeType_StoreStatic:
this->LogToDebugFile("Opcode: Store Static\n");
this->LogToDebugFile("Bit Width: %x\n", opcode->store_static.bit_width);
this->LogToDebugFile("Mem Type: %x\n", opcode->store_static.mem_type);
this->LogToDebugFile("Reg Idx: %x\n", opcode->store_static.offset_register);
this->LogToDebugFile("Rel Addr: %lx\n", opcode->store_static.rel_address);
this->LogToDebugFile("Value: %lx\n", opcode->store_static.value.bit64);
break;
case CheatVmOpcodeType_BeginConditionalBlock:
this->LogToDebugFile("Opcode: Begin Conditional\n");
this->LogToDebugFile("Bit Width: %x\n", opcode->begin_cond.bit_width);
this->LogToDebugFile("Mem Type: %x\n", opcode->begin_cond.mem_type);
this->LogToDebugFile("Cond Type: %x\n", opcode->begin_cond.cond_type);
this->LogToDebugFile("Rel Addr: %lx\n", opcode->begin_cond.rel_address);
this->LogToDebugFile("Value: %lx\n", opcode->begin_cond.value.bit64);
break;
case CheatVmOpcodeType_EndConditionalBlock:
this->LogToDebugFile("Opcode: End Conditional\n");
break;
case CheatVmOpcodeType_ControlLoop:
if (opcode->ctrl_loop.start_loop) {
this->LogToDebugFile("Opcode: Start Loop\n");
this->LogToDebugFile("Reg Idx: %x\n", opcode->ctrl_loop.reg_index);
this->LogToDebugFile("Num Iters: %x\n", opcode->ctrl_loop.num_iters);
} else {
this->LogToDebugFile("Opcode: End Loop\n");
this->LogToDebugFile("Reg Idx: %x\n", opcode->ctrl_loop.reg_index);
}
break;
case CheatVmOpcodeType_LoadRegisterStatic:
this->LogToDebugFile("Opcode: Load Register Static\n");
this->LogToDebugFile("Reg Idx: %x\n", opcode->ldr_static.reg_index);
this->LogToDebugFile("Value: %lx\n", opcode->ldr_static.value);
break;
case CheatVmOpcodeType_LoadRegisterMemory:
this->LogToDebugFile("Opcode: Load Register Memory\n");
this->LogToDebugFile("Bit Width: %x\n", opcode->ldr_memory.bit_width);
this->LogToDebugFile("Reg Idx: %x\n", opcode->ldr_memory.reg_index);
this->LogToDebugFile("Mem Type: %x\n", opcode->ldr_memory.mem_type);
this->LogToDebugFile("From Reg: %d\n", opcode->ldr_memory.load_from_reg);
this->LogToDebugFile("Rel Addr: %lx\n", opcode->ldr_memory.rel_address);
break;
case CheatVmOpcodeType_StoreStaticToAddress:
this->LogToDebugFile("Opcode: Store Static to Address\n");
this->LogToDebugFile("Bit Width: %x\n", opcode->str_static.bit_width);
this->LogToDebugFile("Reg Idx: %x\n", opcode->str_static.reg_index);
if (opcode->str_static.add_offset_reg) {
this->LogToDebugFile("O Reg Idx: %x\n", opcode->str_static.offset_reg_index);
}
this->LogToDebugFile("Incr Reg: %d\n", opcode->str_static.increment_reg);
this->LogToDebugFile("Value: %lx\n", opcode->str_static.value);
break;
case CheatVmOpcodeType_PerformArithmeticStatic:
this->LogToDebugFile("Opcode: Perform Static Arithmetic\n");
this->LogToDebugFile("Bit Width: %x\n", opcode->perform_math_static.bit_width);
this->LogToDebugFile("Reg Idx: %x\n", opcode->perform_math_static.reg_index);
this->LogToDebugFile("Math Type: %x\n", opcode->perform_math_static.math_type);
this->LogToDebugFile("Value: %lx\n", opcode->perform_math_static.value);
break;
case CheatVmOpcodeType_BeginKeypressConditionalBlock:
this->LogToDebugFile("Opcode: Begin Keypress Conditional\n");
this->LogToDebugFile("Key Mask: %x\n", opcode->begin_keypress_cond.key_mask);
break;
case CheatVmOpcodeType_PerformArithmeticRegister:
this->LogToDebugFile("Opcode: Perform Register Arithmetic\n");
this->LogToDebugFile("Bit Width: %x\n", opcode->perform_math_reg.bit_width);
this->LogToDebugFile("Dst Idx: %x\n", opcode->perform_math_reg.dst_reg_index);
this->LogToDebugFile("Src1 Idx: %x\n", opcode->perform_math_reg.src_reg_1_index);
if (opcode->perform_math_reg.has_immediate) {
this->LogToDebugFile("Value: %lx\n", opcode->perform_math_reg.value.bit64);
} else {
this->LogToDebugFile("Src2 Idx: %x\n", opcode->perform_math_reg.src_reg_2_index);
}
break;
case CheatVmOpcodeType_StoreRegisterToAddress:
this->LogToDebugFile("Opcode: Store Register to Address\n");
this->LogToDebugFile("Bit Width: %x\n", opcode->str_register.bit_width);
this->LogToDebugFile("S Reg Idx: %x\n", opcode->str_register.str_reg_index);
this->LogToDebugFile("A Reg Idx: %x\n", opcode->str_register.addr_reg_index);
this->LogToDebugFile("Incr Reg: %d\n", opcode->str_register.increment_reg);
switch (opcode->str_register.ofs_type) {
case StoreRegisterOffsetType_None:
break;
case StoreRegisterOffsetType_Reg:
this->LogToDebugFile("O Reg Idx: %x\n", opcode->str_register.ofs_reg_index);
break;
case StoreRegisterOffsetType_Imm:
this->LogToDebugFile("Rel Addr: %lx\n", opcode->str_register.rel_address);
break;
case StoreRegisterOffsetType_MemReg:
this->LogToDebugFile("Mem Type: %x\n", opcode->str_register.mem_type);
break;
case StoreRegisterOffsetType_MemImm:
case StoreRegisterOffsetType_MemImmReg:
this->LogToDebugFile("Mem Type: %x\n", opcode->str_register.mem_type);
this->LogToDebugFile("Rel Addr: %lx\n", opcode->str_register.rel_address);
break;
}
break;
case CheatVmOpcodeType_BeginRegisterConditionalBlock:
this->LogToDebugFile("Opcode: Begin Register Conditional\n");
this->LogToDebugFile("Bit Width: %x\n", opcode->begin_reg_cond.bit_width);
this->LogToDebugFile("Cond Type: %x\n", opcode->begin_reg_cond.cond_type);
this->LogToDebugFile("V Reg Idx: %x\n", opcode->begin_reg_cond.val_reg_index);
switch (opcode->begin_reg_cond.comp_type) {
case CompareRegisterValueType_StaticValue:
this->LogToDebugFile("Comp Type: Static Value\n");
this->LogToDebugFile("Value: %lx\n", opcode->begin_reg_cond.value.bit64);
break;
case CompareRegisterValueType_OtherRegister:
this->LogToDebugFile("Comp Type: Other Register\n");
this->LogToDebugFile("X Reg Idx: %x\n", opcode->begin_reg_cond.other_reg_index);
break;
case CompareRegisterValueType_MemoryRelAddr:
this->LogToDebugFile("Comp Type: Memory Relative Address\n");
this->LogToDebugFile("Mem Type: %x\n", opcode->begin_reg_cond.mem_type);
this->LogToDebugFile("Rel Addr: %lx\n", opcode->begin_reg_cond.rel_address);
break;
case CompareRegisterValueType_MemoryOfsReg:
this->LogToDebugFile("Comp Type: Memory Offset Register\n");
this->LogToDebugFile("Mem Type: %x\n", opcode->begin_reg_cond.mem_type);
this->LogToDebugFile("O Reg Idx: %x\n", opcode->begin_reg_cond.ofs_reg_index);
break;
case CompareRegisterValueType_RegisterRelAddr:
this->LogToDebugFile("Comp Type: Register Relative Address\n");
this->LogToDebugFile("A Reg Idx: %x\n", opcode->begin_reg_cond.addr_reg_index);
this->LogToDebugFile("Rel Addr: %lx\n", opcode->begin_reg_cond.rel_address);
break;
case CompareRegisterValueType_RegisterOfsReg:
this->LogToDebugFile("Comp Type: Register Offset Register\n");
this->LogToDebugFile("A Reg Idx: %x\n", opcode->begin_reg_cond.addr_reg_index);
this->LogToDebugFile("O Reg Idx: %x\n", opcode->begin_reg_cond.ofs_reg_index);
break;
}
break;
case CheatVmOpcodeType_SaveRestoreRegister:
this->LogToDebugFile("Opcode: Save or Restore Register\n");
this->LogToDebugFile("Dst Idx: %x\n", opcode->save_restore_reg.dst_index);
this->LogToDebugFile("Src Idx: %x\n", opcode->save_restore_reg.src_index);
this->LogToDebugFile("Op Type: %d\n", opcode->save_restore_reg.op_type);
break;
case CheatVmOpcodeType_SaveRestoreRegisterMask:
this->LogToDebugFile("Opcode: Save or Restore Register Mask\n");
this->LogToDebugFile("Op Type: %d\n", opcode->save_restore_regmask.op_type);
for (size_t i = 0; i < NumRegisters; i++) {
this->LogToDebugFile("Act[%02x]: %d\n", i, opcode->save_restore_regmask.should_operate[i]);
}
break;
default:
this->LogToDebugFile("Unknown opcode: %x\n", opcode->opcode);
break;
}
}
bool DmntCheatVm::DecodeNextOpcode(CheatVmOpcode *out) {
/* If we've ever seen a decode failure, return false. */
bool valid = this->decode_success;
CheatVmOpcode opcode = {};
ON_SCOPE_EXIT {
this->decode_success &= valid;
if (valid) {
*out = opcode;
}
};
/* Helper function for getting instruction dwords. */
auto GetNextDword = [&]() {
if (this->instruction_ptr >= this->num_opcodes) {
valid = false;
return static_cast(0);
}
return this->program[this->instruction_ptr++];
};
/* Helper function for parsing a VmInt. */
auto GetNextVmInt = [&](const u32 bit_width) {
VmInt val = {0};
const u32 first_dword = GetNextDword();
switch (bit_width) {
case 1:
val.bit8 = (u8)first_dword;
break;
case 2:
val.bit16 = (u16)first_dword;
break;
case 4:
val.bit32 = first_dword;
break;
case 8:
val.bit64 = (((u64)first_dword) << 32ul) | ((u64)GetNextDword());
break;
}
return val;
};
/* Read opcode. */
const u32 first_dword = GetNextDword();
if (!valid) {
return valid;
}
opcode.opcode = (CheatVmOpcodeType)(((first_dword >> 28) & 0xF));
if (opcode.opcode >= CheatVmOpcodeType_ExtendedWidth) {
opcode.opcode = (CheatVmOpcodeType)((((u32)opcode.opcode) << 4) | ((first_dword >> 24) & 0xF));
}
/* detect condition start. */
switch (opcode.opcode) {
case CheatVmOpcodeType_BeginConditionalBlock:
case CheatVmOpcodeType_BeginKeypressConditionalBlock:
case CheatVmOpcodeType_BeginRegisterConditionalBlock:
opcode.begin_conditional_block = true;
break;
default:
opcode.begin_conditional_block = false;
break;
}
switch (opcode.opcode) {
case CheatVmOpcodeType_StoreStatic:
{
/* 0TMR00AA AAAAAAAA YYYYYYYY (YYYYYYYY) */
/* Read additional words. */
const u32 second_dword = GetNextDword();
opcode.store_static.bit_width = (first_dword >> 24) & 0xF;
opcode.store_static.mem_type = (MemoryAccessType)((first_dword >> 20) & 0xF);
opcode.store_static.offset_register = ((first_dword >> 16) & 0xF);
opcode.store_static.rel_address = ((u64)(first_dword & 0xFF) << 32ul) | ((u64)second_dword);
opcode.store_static.value = GetNextVmInt(opcode.store_static.bit_width);
}
break;
case CheatVmOpcodeType_BeginConditionalBlock:
{
/* 1TMC00AA AAAAAAAA YYYYYYYY (YYYYYYYY) */
/* Read additional words. */
const u32 second_dword = GetNextDword();
opcode.begin_cond.bit_width = (first_dword >> 24) & 0xF;
opcode.begin_cond.mem_type = (MemoryAccessType)((first_dword >> 20) & 0xF);
opcode.begin_cond.cond_type = (ConditionalComparisonType)((first_dword >> 16) & 0xF);
opcode.begin_cond.rel_address = ((u64)(first_dword & 0xFF) << 32ul) | ((u64)second_dword);
opcode.begin_cond.value = GetNextVmInt(opcode.store_static.bit_width);
}
break;
case CheatVmOpcodeType_EndConditionalBlock:
{
/* 20000000 */
/* There's actually nothing left to process here! */
}
break;
case CheatVmOpcodeType_ControlLoop:
{
/* 300R0000 VVVVVVVV */
/* 310R0000 */
/* Parse register, whether loop start or loop end. */
opcode.ctrl_loop.start_loop = ((first_dword >> 24) & 0xF) == 0;
opcode.ctrl_loop.reg_index = ((first_dword >> 20) & 0xF);
/* Read number of iters if loop start. */
if (opcode.ctrl_loop.start_loop) {
opcode.ctrl_loop.num_iters = GetNextDword();
}
}
break;
case CheatVmOpcodeType_LoadRegisterStatic:
{
/* 400R0000 VVVVVVVV VVVVVVVV */
/* Read additional words. */
opcode.ldr_static.reg_index = ((first_dword >> 16) & 0xF);
opcode.ldr_static.value = (((u64)GetNextDword()) << 32ul) | ((u64)GetNextDword());
}
break;
case CheatVmOpcodeType_LoadRegisterMemory:
{
/* 5TMRI0AA AAAAAAAA */
/* Read additional words. */
const u32 second_dword = GetNextDword();
opcode.ldr_memory.bit_width = (first_dword >> 24) & 0xF;
opcode.ldr_memory.mem_type = (MemoryAccessType)((first_dword >> 20) & 0xF);
opcode.ldr_memory.reg_index = ((first_dword >> 16) & 0xF);
opcode.ldr_memory.load_from_reg = ((first_dword >> 12) & 0xF) != 0;
opcode.ldr_memory.rel_address = ((u64)(first_dword & 0xFF) << 32ul) | ((u64)second_dword);
}
break;
case CheatVmOpcodeType_StoreStaticToAddress:
{
/* 6T0RIor0 VVVVVVVV VVVVVVVV */
/* Read additional words. */
opcode.str_static.bit_width = (first_dword >> 24) & 0xF;
opcode.str_static.reg_index = ((first_dword >> 16) & 0xF);
opcode.str_static.increment_reg = ((first_dword >> 12) & 0xF) != 0;
opcode.str_static.add_offset_reg = ((first_dword >> 8) & 0xF) != 0;
opcode.str_static.offset_reg_index = ((first_dword >> 4) & 0xF);
opcode.str_static.value = (((u64)GetNextDword()) << 32ul) | ((u64)GetNextDword());
}
break;
case CheatVmOpcodeType_PerformArithmeticStatic:
{
/* 7T0RC000 VVVVVVVV */
/* Read additional words. */
opcode.perform_math_static.bit_width = (first_dword >> 24) & 0xF;
opcode.perform_math_static.reg_index = ((first_dword >> 16) & 0xF);
opcode.perform_math_static.math_type = (RegisterArithmeticType)((first_dword >> 12) & 0xF);
opcode.perform_math_static.value = GetNextDword();
}
break;
case CheatVmOpcodeType_BeginKeypressConditionalBlock:
{
/* 8kkkkkkk */
/* Just parse the mask. */
opcode.begin_keypress_cond.key_mask = first_dword & 0x0FFFFFFF;
}
break;
case CheatVmOpcodeType_PerformArithmeticRegister:
{
/* 9TCRSIs0 (VVVVVVVV (VVVVVVVV)) */
opcode.perform_math_reg.bit_width = (first_dword >> 24) & 0xF;
opcode.perform_math_reg.math_type = (RegisterArithmeticType)((first_dword >> 20) & 0xF);
opcode.perform_math_reg.dst_reg_index = ((first_dword >> 16) & 0xF);
opcode.perform_math_reg.src_reg_1_index = ((first_dword >> 12) & 0xF);
opcode.perform_math_reg.has_immediate = ((first_dword >> 8) & 0xF) != 0;
if (opcode.perform_math_reg.has_immediate) {
opcode.perform_math_reg.src_reg_2_index = 0;
opcode.perform_math_reg.value = GetNextVmInt(opcode.perform_math_reg.bit_width);
} else {
opcode.perform_math_reg.src_reg_2_index = ((first_dword >> 4) & 0xF);
}
}
break;
case CheatVmOpcodeType_StoreRegisterToAddress:
{
/* ATSRIOxa (aaaaaaaa) */
/* A = opcode 10 */
/* T = bit width */
/* S = src register index */
/* R = address register index */
/* I = 1 if increment address register, 0 if not increment address register */
/* O = offset type, 0 = None, 1 = Register, 2 = Immediate, 3 = Memory Region,
4 = Memory Region + Relative Address (ignore address register), 5 = Memory Region + Relative Address */
/* x = offset register (for offset type 1), memory type (for offset type 3) */
/* a = relative address (for offset type 2+3) */
opcode.str_register.bit_width = (first_dword >> 24) & 0xF;
opcode.str_register.str_reg_index = ((first_dword >> 20) & 0xF);
opcode.str_register.addr_reg_index = ((first_dword >> 16) & 0xF);
opcode.str_register.increment_reg = ((first_dword >> 12) & 0xF) != 0;
opcode.str_register.ofs_type = (StoreRegisterOffsetType)(((first_dword >> 8) & 0xF));
opcode.str_register.ofs_reg_index = ((first_dword >> 4) & 0xF);
switch (opcode.str_register.ofs_type) {
case StoreRegisterOffsetType_None:
case StoreRegisterOffsetType_Reg:
/* Nothing more to do */
break;
case StoreRegisterOffsetType_Imm:
opcode.str_register.rel_address = (((u64)(first_dword & 0xF) << 32ul) | ((u64)GetNextDword()));
break;
case StoreRegisterOffsetType_MemReg:
opcode.str_register.mem_type = (MemoryAccessType)((first_dword >> 4) & 0xF);
break;
case StoreRegisterOffsetType_MemImm:
case StoreRegisterOffsetType_MemImmReg:
opcode.str_register.mem_type = (MemoryAccessType)((first_dword >> 4) & 0xF);
opcode.str_register.rel_address = (((u64)(first_dword & 0xF) << 32ul) | ((u64)GetNextDword()));
break;
default:
opcode.str_register.ofs_type = StoreRegisterOffsetType_None;
break;
}
}
break;
case CheatVmOpcodeType_BeginRegisterConditionalBlock:
{
/* C0TcSX## */
/* C0TcS0Ma aaaaaaaa */
/* C0TcS1Mr */
/* C0TcS2Ra aaaaaaaa */
/* C0TcS3Rr */
/* C0TcS400 VVVVVVVV (VVVVVVVV) */
/* C0TcS5X0 */
/* C0 = opcode 0xC0 */
/* T = bit width */
/* c = condition type. */
/* S = source register. */
/* X = value operand type, 0 = main/heap with relative offset, 1 = main/heap with offset register, */
/* 2 = register with relative offset, 3 = register with offset register, 4 = static value, 5 = other register. */
/* M = memory type. */
/* R = address register. */
/* a = relative address. */
/* r = offset register. */
/* X = other register. */
/* V = value. */
opcode.begin_reg_cond.bit_width = (first_dword >> 20) & 0xF;
opcode.begin_reg_cond.cond_type = (ConditionalComparisonType)((first_dword >> 16) & 0xF);
opcode.begin_reg_cond.val_reg_index = ((first_dword >> 12) & 0xF);
opcode.begin_reg_cond.comp_type = (CompareRegisterValueType)((first_dword >> 8) & 0xF);
switch (opcode.begin_reg_cond.comp_type) {
case CompareRegisterValueType_StaticValue:
opcode.begin_reg_cond.value = GetNextVmInt(opcode.begin_reg_cond.bit_width);
break;
case CompareRegisterValueType_OtherRegister:
opcode.begin_reg_cond.other_reg_index = ((first_dword >> 4) & 0xF);
break;
case CompareRegisterValueType_MemoryRelAddr:
opcode.begin_reg_cond.mem_type = (MemoryAccessType)((first_dword >> 4) & 0xF);
opcode.begin_reg_cond.rel_address = (((u64)(first_dword & 0xF) << 32ul) | ((u64)GetNextDword()));
break;
case CompareRegisterValueType_MemoryOfsReg:
opcode.begin_reg_cond.mem_type = (MemoryAccessType)((first_dword >> 4) & 0xF);
opcode.begin_reg_cond.ofs_reg_index = (first_dword & 0xF);
break;
case CompareRegisterValueType_RegisterRelAddr:
opcode.begin_reg_cond.addr_reg_index = ((first_dword >> 4) & 0xF);
opcode.begin_reg_cond.rel_address = (((u64)(first_dword & 0xF) << 32ul) | ((u64)GetNextDword()));
break;
case CompareRegisterValueType_RegisterOfsReg:
opcode.begin_reg_cond.addr_reg_index = ((first_dword >> 4) & 0xF);
opcode.begin_reg_cond.ofs_reg_index = (first_dword & 0xF);
break;
}
}
break;
case CheatVmOpcodeType_SaveRestoreRegister:
{
/* C10D0Sx0 */
/* C1 = opcode 0xC1 */
/* D = destination index. */
/* S = source index. */
/* x = 3 if clearing reg, 2 if clearing saved value, 1 if saving a register, 0 if restoring a register. */
/* NOTE: If we add more save slots later, current encoding is backwards compatible. */
opcode.save_restore_reg.dst_index = (first_dword >> 16) & 0xF;
opcode.save_restore_reg.src_index = (first_dword >> 8) & 0xF;
opcode.save_restore_reg.op_type = (SaveRestoreRegisterOpType)((first_dword >> 4) & 0xF);
}
break;
case CheatVmOpcodeType_SaveRestoreRegisterMask:
{
/* C2x0XXXX */
/* C2 = opcode 0xC2 */
/* x = 3 if clearing reg, 2 if clearing saved value, 1 if saving, 0 if restoring. */
/* X = 16-bit bitmask, bit i --> save or restore register i. */
opcode.save_restore_regmask.op_type = (SaveRestoreRegisterOpType)((first_dword >> 20) & 0xF);
for (size_t i = 0; i < NumRegisters; i++) {
opcode.save_restore_regmask.should_operate[i] = (first_dword & (1u << i)) != 0;
}
}
break;
case CheatVmOpcodeType_ExtendedWidth:
default:
/* Unrecognized instruction cannot be decoded. */
valid = false;
break;
}
/* End decoding. */
return valid;
}
void DmntCheatVm::SkipConditionalBlock() {
if (this->condition_depth > 0) {
/* We want to continue until we're out of the current block. */
const size_t desired_depth = this->condition_depth - 1;
CheatVmOpcode skip_opcode;
while (this->condition_depth > desired_depth && this->DecodeNextOpcode(&skip_opcode)) {
/* Decode instructions until we see end of the current conditional block. */
/* NOTE: This is broken in gateway's implementation. */
/* Gateway currently checks for "0x2" instead of "0x20000000" */
/* In addition, they do a linear scan instead of correctly decoding opcodes. */
/* This causes issues if "0x2" appears as an immediate in the conditional block... */
/* We also support nesting of conditional blocks, and Gateway does not. */
if (skip_opcode.begin_conditional_block) {
this->condition_depth++;
} else if (skip_opcode.opcode == CheatVmOpcodeType_EndConditionalBlock) {
this->condition_depth--;
}
}
} else {
/* Skipping, but this->condition_depth = 0. */
/* This is an error condition. */
/* However, I don't actually believe it is possible for this to happen. */
/* I guess we'll throw a fatal error here, so as to encourage me to fix the VM */
/* in the event that someone triggers it? I don't know how you'd do that. */
fatalSimple(ResultDmntCheatVmInvalidCondDepth);
}
}
u64 DmntCheatVm::GetVmInt(VmInt value, u32 bit_width) {
switch (bit_width) {
case 1:
return value.bit8;
case 2:
return value.bit16;
case 4:
return value.bit32;
case 8:
return value.bit64;
default:
/* Invalid bit width -> return 0. */
return 0;
}
}
u64 DmntCheatVm::GetCheatProcessAddress(const CheatProcessMetadata* metadata, MemoryAccessType mem_type, u64 rel_address) {
switch (mem_type) {
case MemoryAccessType_MainNso:
default:
return metadata->main_nso_extents.base + rel_address;
case MemoryAccessType_Heap:
return metadata->heap_extents.base + rel_address;
}
}
void DmntCheatVm::ResetState() {
for (size_t i = 0; i < DmntCheatVm::NumRegisters; i++) {
this->registers[i] = 0;
this->saved_values[i] = 0;
this->loop_tops[i] = 0;
}
this->instruction_ptr = 0;
this->condition_depth = 0;
this->decode_success = true;
}
bool DmntCheatVm::LoadProgram(const CheatEntry *cheats, size_t num_cheats) {
/* Reset opcode count. */
this->num_opcodes = 0;
for (size_t i = 0; i < num_cheats; i++) {
if (cheats[i].enabled) {
/* Bounds check. */
if (cheats[i].definition.num_opcodes + this->num_opcodes > MaximumProgramOpcodeCount) {
this->num_opcodes = 0;
return false;
}
for (size_t n = 0; n < cheats[i].definition.num_opcodes; n++) {
this->program[this->num_opcodes++] = cheats[i].definition.opcodes[n];
}
}
}
return true;
}
void DmntCheatVm::Execute(const CheatProcessMetadata *metadata) {
CheatVmOpcode cur_opcode;
u64 kDown = 0;
/* Get Keys down. */
HidManagement::GetKeysDown(&kDown);
this->OpenDebugLogFile();
ON_SCOPE_EXIT { this->CloseDebugLogFile(); };
this->LogToDebugFile("Started VM execution.\n");
this->LogToDebugFile("Main NSO: %012lx\n", metadata->main_nso_extents.base);
this->LogToDebugFile("Heap: %012lx\n", metadata->main_nso_extents.base);
this->LogToDebugFile("Keys Down: %08x\n", (u32)(kDown & 0x0FFFFFFF));
/* Clear VM state. */
this->ResetState();
/* Loop until program finishes. */
while (this->DecodeNextOpcode(&cur_opcode)) {
this->LogToDebugFile("Instruction Ptr: %04x\n", (u32)this->instruction_ptr);
for (size_t i = 0; i < NumRegisters; i++) {
this->LogToDebugFile("Registers[%02x]: %016lx\n", i, this->registers[i]);
}
for (size_t i = 0; i < NumRegisters; i++) {
this->LogToDebugFile("SavedRegs[%02x]: %016lx\n", i, this->saved_values[i]);
}
this->LogOpcode(&cur_opcode);
/* Increment conditional depth, if relevant. */
if (cur_opcode.begin_conditional_block) {
this->condition_depth++;
}
switch (cur_opcode.opcode) {
case CheatVmOpcodeType_StoreStatic:
{
/* Calculate address, write value to memory. */
u64 dst_address = GetCheatProcessAddress(metadata, cur_opcode.store_static.mem_type, cur_opcode.store_static.rel_address + this->registers[cur_opcode.store_static.offset_register]);
u64 dst_value = GetVmInt(cur_opcode.store_static.value, cur_opcode.store_static.bit_width);
switch (cur_opcode.store_static.bit_width) {
case 1:
case 2:
case 4:
case 8:
DmntCheatManager::WriteCheatProcessMemoryForVm(dst_address, &dst_value, cur_opcode.store_static.bit_width);
break;
}
}
break;
case CheatVmOpcodeType_BeginConditionalBlock:
{
/* Read value from memory. */
u64 src_address = GetCheatProcessAddress(metadata, cur_opcode.begin_cond.mem_type, cur_opcode.begin_cond.rel_address);
u64 src_value = 0;
switch (cur_opcode.store_static.bit_width) {
case 1:
case 2:
case 4:
case 8:
DmntCheatManager::ReadCheatProcessMemoryForVm(src_address, &src_value, cur_opcode.begin_cond.bit_width);
break;
}
/* Check against condition. */
u64 cond_value = GetVmInt(cur_opcode.begin_cond.value, cur_opcode.begin_cond.bit_width);
bool cond_met = false;
switch (cur_opcode.begin_cond.cond_type) {
case ConditionalComparisonType_GT:
cond_met = src_value > cond_value;
break;
case ConditionalComparisonType_GE:
cond_met = src_value >= cond_value;
break;
case ConditionalComparisonType_LT:
cond_met = src_value < cond_value;
break;
case ConditionalComparisonType_LE:
cond_met = src_value <= cond_value;
break;
case ConditionalComparisonType_EQ:
cond_met = src_value == cond_value;
break;
case ConditionalComparisonType_NE:
cond_met = src_value != cond_value;
break;
}
/* Skip conditional block if condition not met. */
if (!cond_met) {
this->SkipConditionalBlock();
}
}
break;
case CheatVmOpcodeType_EndConditionalBlock:
/* Decrement the condition depth. */
/* We will assume, graciously, that mismatched conditional block ends are a nop. */
if (this->condition_depth > 0) {
this->condition_depth--;
}
break;
case CheatVmOpcodeType_ControlLoop:
if (cur_opcode.ctrl_loop.start_loop) {
/* Start a loop. */
this->registers[cur_opcode.ctrl_loop.reg_index] = cur_opcode.ctrl_loop.num_iters;
this->loop_tops[cur_opcode.ctrl_loop.reg_index] = this->instruction_ptr;
} else {
/* End a loop. */
this->registers[cur_opcode.ctrl_loop.reg_index]--;
if (this->registers[cur_opcode.ctrl_loop.reg_index] != 0) {
this->instruction_ptr = this->loop_tops[cur_opcode.ctrl_loop.reg_index];
}
}
break;
case CheatVmOpcodeType_LoadRegisterStatic:
/* Set a register to a static value. */
this->registers[cur_opcode.ldr_static.reg_index] = cur_opcode.ldr_static.value;
break;
case CheatVmOpcodeType_LoadRegisterMemory:
{
/* Choose source address. */
u64 src_address;
if (cur_opcode.ldr_memory.load_from_reg) {
src_address = this->registers[cur_opcode.ldr_memory.reg_index] + cur_opcode.ldr_memory.rel_address;
} else {
src_address = GetCheatProcessAddress(metadata, cur_opcode.ldr_memory.mem_type, cur_opcode.ldr_memory.rel_address);
}
/* Read into register. Gateway only reads on valid bitwidth. */
switch (cur_opcode.ldr_memory.bit_width) {
case 1:
case 2:
case 4:
case 8:
DmntCheatManager::ReadCheatProcessMemoryForVm(src_address, &this->registers[cur_opcode.ldr_memory.reg_index], cur_opcode.ldr_memory.bit_width);
break;
}
}
break;
case CheatVmOpcodeType_StoreStaticToAddress:
{
/* Calculate address. */
u64 dst_address = this->registers[cur_opcode.str_static.reg_index];
u64 dst_value = cur_opcode.str_static.value;
if (cur_opcode.str_static.add_offset_reg) {
dst_address += this->registers[cur_opcode.str_static.offset_reg_index];
}
/* Write value to memory. Gateway only writes on valid bitwidth. */
switch (cur_opcode.str_static.bit_width) {
case 1:
case 2:
case 4:
case 8:
DmntCheatManager::WriteCheatProcessMemoryForVm(dst_address, &dst_value, cur_opcode.str_static.bit_width);
break;
}
/* Increment register if relevant. */
if (cur_opcode.str_static.increment_reg) {
this->registers[cur_opcode.str_static.reg_index] += cur_opcode.str_static.bit_width;
}
}
break;
case CheatVmOpcodeType_PerformArithmeticStatic:
{
/* Do requested math. */
switch (cur_opcode.perform_math_static.math_type) {
case RegisterArithmeticType_Addition:
this->registers[cur_opcode.perform_math_static.reg_index] += (u64)cur_opcode.perform_math_static.value;
break;
case RegisterArithmeticType_Subtraction:
this->registers[cur_opcode.perform_math_static.reg_index] -= (u64)cur_opcode.perform_math_static.value;
break;
case RegisterArithmeticType_Multiplication:
this->registers[cur_opcode.perform_math_static.reg_index] *= (u64)cur_opcode.perform_math_static.value;
break;
case RegisterArithmeticType_LeftShift:
this->registers[cur_opcode.perform_math_static.reg_index] <<= (u64)cur_opcode.perform_math_static.value;
break;
case RegisterArithmeticType_RightShift:
this->registers[cur_opcode.perform_math_static.reg_index] >>= (u64)cur_opcode.perform_math_static.value;
break;
default:
/* Do not handle extensions here. */
break;
}
/* Apply bit width. */
switch (cur_opcode.perform_math_static.bit_width) {
case 1:
this->registers[cur_opcode.perform_math_static.reg_index] = static_cast(this->registers[cur_opcode.perform_math_static.reg_index]);
break;
case 2:
this->registers[cur_opcode.perform_math_static.reg_index] = static_cast(this->registers[cur_opcode.perform_math_static.reg_index]);
break;
case 4:
this->registers[cur_opcode.perform_math_static.reg_index] = static_cast(this->registers[cur_opcode.perform_math_static.reg_index]);
break;
case 8:
this->registers[cur_opcode.perform_math_static.reg_index] = static_cast(this->registers[cur_opcode.perform_math_static.reg_index]);
break;
}
}
break;
case CheatVmOpcodeType_BeginKeypressConditionalBlock:
/* Check for keypress. */
if ((cur_opcode.begin_keypress_cond.key_mask & kDown) != cur_opcode.begin_keypress_cond.key_mask) {
/* Keys not pressed. Skip conditional block. */
this->SkipConditionalBlock();
}
break;
case CheatVmOpcodeType_PerformArithmeticRegister:
{
const u64 operand_1_value = this->registers[cur_opcode.perform_math_reg.src_reg_1_index];
const u64 operand_2_value = cur_opcode.perform_math_reg.has_immediate ?
GetVmInt(cur_opcode.perform_math_reg.value, cur_opcode.perform_math_reg.bit_width) :
this->registers[cur_opcode.perform_math_reg.src_reg_2_index];
u64 res_val = 0;
/* Do requested math. */
switch (cur_opcode.perform_math_reg.math_type) {
case RegisterArithmeticType_Addition:
res_val = operand_1_value + operand_2_value;
break;
case RegisterArithmeticType_Subtraction:
res_val = operand_1_value - operand_2_value;
break;
case RegisterArithmeticType_Multiplication:
res_val = operand_1_value * operand_2_value;
break;
case RegisterArithmeticType_LeftShift:
res_val = operand_1_value << operand_2_value;
break;
case RegisterArithmeticType_RightShift:
res_val = operand_1_value >> operand_2_value;
break;
case RegisterArithmeticType_LogicalAnd:
res_val = operand_1_value & operand_2_value;
break;
case RegisterArithmeticType_LogicalOr:
res_val = operand_1_value | operand_2_value;
break;
case RegisterArithmeticType_LogicalNot:
res_val = ~operand_1_value;
break;
case RegisterArithmeticType_LogicalXor:
res_val = operand_1_value ^ operand_2_value;
break;
case RegisterArithmeticType_None:
res_val = operand_1_value;
break;
}
/* Apply bit width. */
switch (cur_opcode.perform_math_reg.bit_width) {
case 1:
res_val = static_cast(res_val);
break;
case 2:
res_val = static_cast(res_val);
break;
case 4:
res_val = static_cast(res_val);
break;
case 8:
res_val = static_cast(res_val);
break;
}
/* Save to register. */
this->registers[cur_opcode.perform_math_reg.dst_reg_index] = res_val;
}
break;
case CheatVmOpcodeType_StoreRegisterToAddress:
{
/* Calculate address. */
u64 dst_value = this->registers[cur_opcode.str_register.str_reg_index];
u64 dst_address = this->registers[cur_opcode.str_register.addr_reg_index];
switch (cur_opcode.str_register.ofs_type) {
case StoreRegisterOffsetType_None:
/* Nothing more to do */
break;
case StoreRegisterOffsetType_Reg:
dst_address += this->registers[cur_opcode.str_register.ofs_reg_index];
break;
case StoreRegisterOffsetType_Imm:
dst_address += cur_opcode.str_register.rel_address;
break;
case StoreRegisterOffsetType_MemReg:
dst_address = GetCheatProcessAddress(metadata, cur_opcode.str_register.mem_type, this->registers[cur_opcode.str_register.addr_reg_index]);
break;
case StoreRegisterOffsetType_MemImm:
dst_address = GetCheatProcessAddress(metadata, cur_opcode.str_register.mem_type, cur_opcode.str_register.rel_address);
break;
case StoreRegisterOffsetType_MemImmReg:
dst_address = GetCheatProcessAddress(metadata, cur_opcode.str_register.mem_type, this->registers[cur_opcode.str_register.addr_reg_index] + cur_opcode.str_register.rel_address);
break;
}
/* Write value to memory. Write only on valid bitwidth. */
switch (cur_opcode.str_register.bit_width) {
case 1:
case 2:
case 4:
case 8:
DmntCheatManager::WriteCheatProcessMemoryForVm(dst_address, &dst_value, cur_opcode.str_register.bit_width);
break;
}
/* Increment register if relevant. */
if (cur_opcode.str_register.increment_reg) {
this->registers[cur_opcode.str_register.addr_reg_index] += cur_opcode.str_register.bit_width;
}
}
break;
case CheatVmOpcodeType_BeginRegisterConditionalBlock:
{
/* Get value from register. */
u64 src_value = 0;
switch (cur_opcode.begin_reg_cond.bit_width) {
case 1:
src_value = static_cast(this->registers[cur_opcode.begin_reg_cond.val_reg_index] & 0xFFul);
break;
case 2:
src_value = static_cast(this->registers[cur_opcode.begin_reg_cond.val_reg_index] & 0xFFFFul);
break;
case 4:
src_value = static_cast(this->registers[cur_opcode.begin_reg_cond.val_reg_index] & 0xFFFFFFFFul);
break;
case 8:
src_value = static_cast(this->registers[cur_opcode.begin_reg_cond.val_reg_index] & 0xFFFFFFFFFFFFFFFFul);
break;
}
/* Read value from memory. */
u64 cond_value = 0;
if (cur_opcode.begin_reg_cond.comp_type == CompareRegisterValueType_StaticValue) {
cond_value = GetVmInt(cur_opcode.begin_reg_cond.value, cur_opcode.begin_reg_cond.bit_width);
} else if (cur_opcode.begin_reg_cond.comp_type == CompareRegisterValueType_OtherRegister) {
switch (cur_opcode.begin_reg_cond.bit_width) {
case 1:
cond_value = static_cast(this->registers[cur_opcode.begin_reg_cond.other_reg_index] & 0xFFul);
break;
case 2:
cond_value = static_cast(this->registers[cur_opcode.begin_reg_cond.other_reg_index] & 0xFFFFul);
break;
case 4:
cond_value = static_cast(this->registers[cur_opcode.begin_reg_cond.other_reg_index] & 0xFFFFFFFFul);
break;
case 8:
cond_value = static_cast(this->registers[cur_opcode.begin_reg_cond.other_reg_index] & 0xFFFFFFFFFFFFFFFFul);
break;
}
} else {
u64 cond_address = 0;
switch (cur_opcode.begin_reg_cond.comp_type) {
case CompareRegisterValueType_MemoryRelAddr:
cond_address = GetCheatProcessAddress(metadata, cur_opcode.begin_reg_cond.mem_type, cur_opcode.begin_reg_cond.rel_address);
break;
case CompareRegisterValueType_MemoryOfsReg:
cond_address = GetCheatProcessAddress(metadata, cur_opcode.begin_reg_cond.mem_type, this->registers[cur_opcode.begin_reg_cond.ofs_reg_index]);
break;
case CompareRegisterValueType_RegisterRelAddr:
cond_address = this->registers[cur_opcode.begin_reg_cond.addr_reg_index] + cur_opcode.begin_reg_cond.rel_address;
break;
case CompareRegisterValueType_RegisterOfsReg:
cond_address = this->registers[cur_opcode.begin_reg_cond.addr_reg_index] + this->registers[cur_opcode.begin_reg_cond.ofs_reg_index];
break;
default:
break;
}
switch (cur_opcode.begin_reg_cond.bit_width) {
case 1:
case 2:
case 4:
case 8:
DmntCheatManager::ReadCheatProcessMemoryForVm(cond_address, &cond_value, cur_opcode.begin_reg_cond.bit_width);
break;
}
}
/* Check against condition. */
bool cond_met = false;
switch (cur_opcode.begin_reg_cond.cond_type) {
case ConditionalComparisonType_GT:
cond_met = src_value > cond_value;
break;
case ConditionalComparisonType_GE:
cond_met = src_value >= cond_value;
break;
case ConditionalComparisonType_LT:
cond_met = src_value < cond_value;
break;
case ConditionalComparisonType_LE:
cond_met = src_value <= cond_value;
break;
case ConditionalComparisonType_EQ:
cond_met = src_value == cond_value;
break;
case ConditionalComparisonType_NE:
cond_met = src_value != cond_value;
break;
}
/* Skip conditional block if condition not met. */
if (!cond_met) {
this->SkipConditionalBlock();
}
}
break;
case CheatVmOpcodeType_SaveRestoreRegister:
/* Save or restore a register. */
switch (cur_opcode.save_restore_reg.op_type) {
case SaveRestoreRegisterOpType_ClearRegs:
this->registers[cur_opcode.save_restore_reg.dst_index] = 0ul;
break;
case SaveRestoreRegisterOpType_ClearSaved:
this->saved_values[cur_opcode.save_restore_reg.dst_index] = 0ul;
break;
case SaveRestoreRegisterOpType_Save:
this->saved_values[cur_opcode.save_restore_reg.dst_index] = this->registers[cur_opcode.save_restore_reg.src_index];
break;
case SaveRestoreRegisterOpType_Restore:
default:
this->registers[cur_opcode.save_restore_reg.dst_index] = this->saved_values[cur_opcode.save_restore_reg.src_index];
break;
}
break;
case CheatVmOpcodeType_SaveRestoreRegisterMask:
/* Save or restore register mask. */
u64 *src;
u64 *dst;
switch (cur_opcode.save_restore_regmask.op_type) {
case SaveRestoreRegisterOpType_ClearSaved:
case SaveRestoreRegisterOpType_Save:
src = this->registers;
dst = this->saved_values;
break;
case SaveRestoreRegisterOpType_ClearRegs:
case SaveRestoreRegisterOpType_Restore:
default:
src = this->registers;
dst = this->saved_values;
break;
}
for (size_t i = 0; i < NumRegisters; i++) {
if (cur_opcode.save_restore_regmask.should_operate[i]) {
switch (cur_opcode.save_restore_regmask.op_type) {
case SaveRestoreRegisterOpType_ClearSaved:
case SaveRestoreRegisterOpType_ClearRegs:
dst[i] = 0ul;
break;
case SaveRestoreRegisterOpType_Save:
case SaveRestoreRegisterOpType_Restore:
default:
dst[i] = src[i];
break;
}
}
}
break;
default:
/* By default, we do a no-op. */
break;
}
}
}