/* * 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" 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; } } } 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; } /* 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; } } }