dmnt-cheat: Begin implementing Cheat VM.

stratosphere/dmnt/source/dmnt_cheat_manager.cpp

@@ -16,12 +16,14 @@
  
 #include <switch.h>
 #include "dmnt_cheat_manager.hpp"
+#include "dmnt_cheat_vm.hpp"
 #include "pm_shim.h"
 
 static HosMutex g_cheat_lock;
 static HosThread g_detect_thread, g_vm_thread;
 
 static IEvent *g_cheat_process_event;
+static DmntCheatVm *g_cheat_vm;
 
 static CheatProcessMetadata g_cheat_process_metadata = {0};
 static Handle g_cheat_process_debug_hnd = 0;
@@ -189,9 +191,13 @@ void DmntCheatManager::VmThread(void *arg) {
             std::scoped_lock<HosMutex> lk(g_cheat_lock);
             
             if (HasActiveCheatProcess()) {
+                /* Handle any pending debug events. */
                 ContinueCheatProcess();
                 
-                /* TODO: Execute VM. */
+                /* Execute VM. */
+                if (g_cheat_vm->GetProgramSize() != 0) {
+                    g_cheat_vm->Execute(&g_cheat_process_metadata);
+                }
             }
         }
         svcSleepThread(0x5000000ul);
@@ -224,6 +230,9 @@ void DmntCheatManager::InitializeCheatManager() {
     /* Create cheat process detection event. */
     g_cheat_process_event = CreateWriteOnlySystemEvent();
     
+    /* Create cheat vm. */
+    g_cheat_vm = new DmntCheatVm();
+    
     /* Spawn application detection thread, spawn cheat vm thread. */
     if (R_FAILED(g_detect_thread.Initialize(&DmntCheatManager::DetectThread, nullptr, 0x4000, 28))) {
         std::abort();

stratosphere/dmnt/source/dmnt_cheat_service.cpp

@@ -72,7 +72,7 @@ Result DmntCheatService::ToggleCheat(u32 cheat_id) {
     return 0xF601;
 }
 
-Result DmntCheatService::AddCheat(InBuffer<CheatEntry> cheat) {
+Result DmntCheatService::AddCheat(InBuffer<CheatDefinition> cheat, Out<u32> out_cheat_id, bool enabled) {
     /* TODO */
     return 0xF601;
 }

stratosphere/dmnt/source/dmnt_cheat_vm.cpp

@@ -0,0 +1,109 @@
+/*
+ * 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;
+        }
+    }
+}
+
+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.register_index] = cur_opcode.ctrl_loop.num_iters;
+                    this->loop_tops[cur_opcode.ctrl_loop.register_index] = this->instruction_ptr;
+                } else {
+                    /* End a loop. */
+                    this->registers[cur_opcode.ctrl_loop.register_index]--;
+                    if (this->registers[cur_opcode.ctrl_loop.register_index] != 0) {
+                        this->instruction_ptr = this->loop_tops[cur_opcode.ctrl_loop.register_index];
+                    }
+                }
+                break;
+            case CheatVmOpcodeType_LoadRegisterStatic:
+                /* Set a register to a static value. */
+                this->registers[cur_opcode.ldr_static.register_index] = cur_opcode.ldr_static.value;
+                break;
+            case CheatVmOpcodeType_LoadRegisterMemory:
+                {
+                    /* TODO */
+                }
+                break;
+            case CheatVmOpcodeType_StoreToRegisterAddress:
+                {
+                    /* TODO */
+                }
+                break;
+            case CheatVmOpcodeType_PerformArithmetic:
+                {
+                    /* TODO */
+                }
+                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;
+        }
+    }
+}

stratosphere/dmnt/source/dmnt_cheat_vm.hpp

@@ -0,0 +1,157 @@
+/*
+ * 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/>.
+ */
+ 
+#pragma once
+#include <switch.h>
+#include <stratosphere.hpp>
+
+#include "dmnt_cheat_types.hpp"
+
+enum CheatVmOpcodeType : u32 {
+    CheatVmOpcodeType_StoreStatic = 0,
+    CheatVmOpcodeType_BeginConditionalBlock = 1,
+    CheatVmOpcodeType_EndConditionalBlock = 2,
+    CheatVmOpcodeType_ControlLoop = 3,
+    CheatVmOpcodeType_LoadRegisterStatic = 4,
+    CheatVmOpcodeType_LoadRegisterMemory = 5,
+    CheatVmOpcodeType_StoreToRegisterAddress = 6,
+    CheatVmOpcodeType_PerformArithmetic = 7,
+    CheatVmOpcodeType_BeginKeypressConditionalBlock = 8,
+};
+
+enum MemoryAccessType : u32 {
+    MemoryAccessType_MainNso = 0,
+    MemoryAccessType_Heap = 1,
+};
+
+enum ConditionalComparisonType : u32 {
+    ConditionalComparisonType_GT = 1,
+    ConditionalComparisonType_GE = 2,
+    ConditionalComparisonType_LT = 3,
+    ConditionalComparisonType_LE = 4,
+    ConditionalComparisonType_EQ = 5,
+    ConditionalComparisonType_NE = 6,
+};
+
+enum RegisterArithmeticType : u32 {
+    RegisterArithmeticType_Addition = 0,
+    RegisterArithmeticType_Subtraction = 1,
+    RegisterArithmeticType_Multiplication = 2,
+    RegisterArithmeticType_LeftShift = 3,
+    RegisterArithmeticType_RightShift = 4,
+};
+
+union VmInt {
+    u8  bit8;
+    u16 bit16;
+    u32 bit32;
+    u64 bit64;
+};
+
+struct StoreStaticOpcode {
+    u32 bit_width;
+    MemoryAccessType mem_type;
+    u32 offset_register;
+    u64 relative_address;
+    VmInt value;
+};
+
+struct BeginConditionalOpcode {
+    u32 bit_width;
+    MemoryAccessType mem_type;
+    ConditionalComparisonType cond_type;
+    u64 relative_address;
+    VmInt value;
+};
+
+struct EndConditionalOpcode {};
+
+struct ControlLoopOpcode {
+    bool start_loop;
+    u32 register_index;
+    u32 num_iters;
+};
+
+struct LoadRegisterStaticOpcode {
+    u32 register_index;
+    u64 value;
+};
+
+struct LoadRegisterMemoryOpcode {
+    u32 bit_width;
+    MemoryAccessType mem_type;
+    u32 reg_index;
+    bool load_from_reg;
+    u64 relative_address;
+};
+
+struct StoreToRegisterAddressOpcode {
+    u32 bit_width;
+    u32 reg_index;
+    bool increment_reg;
+    bool add_offset_reg;
+    u32 offset_reg_index;
+    u64 value;
+};
+
+struct PerformArithmeticOpcode {
+    u32 bit_width;
+    u32 reg_index;
+    RegisterArithmeticType math_type;
+    VmInt value;
+};
+
+struct BeginKeypressConditionalOpcode {
+    u32 key_mask;
+};
+
+struct CheatVmOpcode {
+    CheatVmOpcodeType opcode;
+    union {
+        StoreStaticOpcode store_static;
+        BeginConditionalOpcode begin_cond;
+        EndConditionalOpcode end_cond;
+        ControlLoopOpcode ctrl_loop;
+        LoadRegisterStaticOpcode ldr_static;
+        LoadRegisterMemoryOpcode ldr_memory;
+        StoreToRegisterAddressOpcode str_regaddr;
+        PerformArithmeticOpcode perform_math;
+        BeginKeypressConditionalOpcode begin_keypress_cond;
+    };
+};
+
+class DmntCheatVm {
+    public:
+        constexpr static size_t MaximumProgramOpcodeCount = 0x400;
+        constexpr static size_t NumRegisters = 0x10;
+    private:
+        size_t num_opcodes = 0;
+        size_t instruction_ptr = 0;
+        u32 program[MaximumProgramOpcodeCount] = {0};
+        u64 registers[NumRegisters] = {0};
+        size_t loop_tops[NumRegisters] = {0};
+    private:
+        bool DecodeNextOpcode(CheatVmOpcode *out);
+        void SkipConditionalBlock();
+    public:
+        DmntCheatVm() { }
+        
+        size_t GetProgramSize() {
+            return this->num_opcodes;
+        }
+        
+        void Execute(const CheatProcessMetadata *metadata);
+};