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dmnt-cheat: finish vm instruction decoder

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This commit is contained in:
Michael Scire 2019-03-03 09:09:21 -08:00
parent af70a4a3a3
commit afae7eaa11
1 changed files with 103 additions and 19 deletions
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122
stratosphere/dmnt/source/dmnt_cheat_vm.cpp
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@ -20,7 +20,7 @@
#include "dmnt_cheat_manager.hpp"
bool DmntCheatVm::DecodeNextOpcode(CheatVmOpcode *out) {
/* If we've ever seen a decode failure, return true. */
/* If we've ever seen a decode failure, return false. */
bool valid = this->decode_success;
CheatVmOpcode opcode = {};
ON_SCOPE_EXIT {
@ -30,70 +30,154 @@ bool DmntCheatVm::DecodeNextOpcode(CheatVmOpcode *out) {
}
};
/* If we have ever seen a decode failure, don't decode any more. */
/* Helper function for getting instruction dwords. */
auto GetNextDword = [&]() {
if (this->instruction_ptr >= this->num_opcodes) {
valid = false;
return static_cast<u32>(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;
}
/* Validate instruction pointer. */
if (this->instruction_ptr >= this->num_opcodes) {
valid = false;
return valid;
}
/* Read opcode. */
const u32 first_dword = this->program[this->instruction_ptr++];
opcode.opcode = (CheatVmOpcodeType)(((first_dword >> 28) & 0xF));
switch (opcode.opcode) {
case CheatVmOpcodeType_StoreStatic:
{
/* TODO */
/* 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:
{
/* TODO */
/* 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:
{
/* TODO */
/* 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:
{
/* TODO */
/* 400R0000 VVVVVVVV VVVVVVVV */
/* Read additional words. */
opcode.ldr_static.reg_index = ((first_dword >> 20) & 0xF);
opcode.ldr_static.value = (((u64)GetNextDword()) << 32ul) | ((u64)GetNextDword());
}
break;
case CheatVmOpcodeType_LoadRegisterMemory:
{
/* TODO */
/* 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_StoreToRegisterAddress:
{
/* TODO */
/* 6T0RIor0 VVVVVVVV VVVVVVVV */
/* Read additional words. */
opcode.str_regaddr.bit_width = (first_dword >> 24) & 0xF;
opcode.str_regaddr.reg_index = ((first_dword >> 16) & 0xF);
opcode.str_regaddr.increment_reg = ((first_dword >> 12) & 0xF) == 0;
opcode.str_regaddr.add_offset_reg = ((first_dword >> 8) & 0xF) == 0;
opcode.str_regaddr.offset_reg_index = ((first_dword >> 4) & 0xF);
opcode.str_regaddr.value = (((u64)GetNextDword()) << 32ul) | ((u64)GetNextDword());
}
break;
case CheatVmOpcodeType_PerformArithmeticStatic:
{
/* TODO */
/* 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:
{
/* TODO */
/* 8kkkkkkk */
/* Just parse the mask. */
opcode.begin_keypress_cond.key_mask = first_dword & 0x0FFFFFFF;
}
break;
case CheatVmOpcodeType_PerformArithmeticRegister:
{
/* TODO */
/* 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;
default: