Atmosphere/stratosphere/dmnt/source/dmnt_cheat_vm.cpp
2019-02-27 19:30:29 -08:00

223 lines
10 KiB
C++

/*
* 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 <http://www.gnu.org/licenses/>.
*/
#include <switch.h>
#include "dmnt_cheat_types.hpp"
#include "dmnt_cheat_vm.hpp"
bool DmntCheatVm::DecodeNextOpcode(CheatVmOpcode *out) {
/* TODO: Parse opcodes */
return false;
}
void DmntCheatVm::SkipConditionalBlock() {
CheatVmOpcode skip_opcode;
while (this->DecodeNextOpcode(&skip_opcode)) {
/* Decode instructions until we see end of 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... */
if (skip_opcode.opcode == CheatVmOpcodeType_EndConditionalBlock) {
break;
}
}
}
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;
}
}
void DmntCheatVm::Execute(const CheatProcessMetadata *metadata) {
CheatVmOpcode cur_opcode;
u64 kDown = 0;
/* TODO: Get Keys down. */
/* Clear VM state. */
for (size_t i = 0; i < DmntCheatVm::NumRegisters; i++) {
this->registers[i] = 0;
this->loop_tops[i] = 0;
}
/* Loop until program finishes. */
while (this->DecodeNextOpcode(&cur_opcode)) {
switch (cur_opcode.opcode) {
case CheatVmOpcodeType_StoreStatic:
{
/* TODO */
}
break;
case CheatVmOpcodeType_BeginConditionalBlock:
{
/* TODO */
}
break;
case CheatVmOpcodeType_EndConditionalBlock:
/* There is nothing to do here. Just move on to the next instruction. */
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:
{
/* TODO */
}
break;
case CheatVmOpcodeType_StoreToRegisterAddress:
{
/* TODO */
}
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<u8>(this->registers[cur_opcode.perform_math_static.reg_index]);
break;
case 2:
this->registers[cur_opcode.perform_math_static.reg_index] = static_cast<u16>(this->registers[cur_opcode.perform_math_static.reg_index]);
break;
case 4:
this->registers[cur_opcode.perform_math_static.reg_index] = static_cast<u32>(this->registers[cur_opcode.perform_math_static.reg_index]);
break;
case 8:
this->registers[cur_opcode.perform_math_static.reg_index] = static_cast<u64>(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<u8>(res_val);
break;
case 2:
res_val = static_cast<u16>(res_val);
break;
case 4:
res_val = static_cast<u32>(res_val);
break;
case 8:
res_val = static_cast<u64>(res_val);
break;
}
/* Save to register. */
this->registers[cur_opcode.perform_math_reg.dst_reg_index] = res_val;
}
break;
}
}
}