dmnt-cheat: Add Save/Restore register opcode

This commit is contained in:
Michael Scire 2019-04-04 12:16:00 -07:00
parent a0f3183c79
commit 477bee2e4c
2 changed files with 40 additions and 0 deletions

View file

@ -188,6 +188,12 @@ void DmntCheatVm::LogOpcode(const CheatVmOpcode *opcode) {
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("Is Save: %d\n", opcode->save_restore_reg.is_save);
break;
default:
this->LogToDebugFile("Unknown opcode: %x\n", opcode->opcode);
break;
@ -462,6 +468,19 @@ bool DmntCheatVm::DecodeNextOpcode(CheatVmOpcode *out) {
}
}
break;
case CheatVmOpcodeType_SaveRestoreRegister:
{
/* C10D0Sx0 */
/* C1 = opcode 0xC1 */
/* D = destination index. */
/* S = source index. */
/* x = 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.is_save = ((first_dword >> 4) & 0xF) != 0;
}
break;
case CheatVmOpcodeType_ExtendedWidth:
default:
/* Unrecognized instruction cannot be decoded. */
@ -532,6 +551,7 @@ u64 DmntCheatVm::GetCheatProcessAddress(const CheatProcessMetadata* metadata, Me
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;
@ -585,6 +605,10 @@ void DmntCheatVm::Execute(const CheatProcessMetadata *metadata) {
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. */
@ -964,6 +988,14 @@ void DmntCheatVm::Execute(const CheatProcessMetadata *metadata) {
}
}
break;
case CheatVmOpcodeType_SaveRestoreRegister:
/* Save or restore a register. */
if (cur_opcode.save_restore_reg.is_save) {
this->saved_values[cur_opcode.save_restore_reg.dst_index] = this->registers[cur_opcode.save_restore_reg.src_index];
} else {
this->registers[cur_opcode.save_restore_reg.dst_index] = this->saved_values[cur_opcode.save_restore_reg.src_index];
}
break;
default:
/* By default, we do a no-op. */
break;

View file

@ -43,6 +43,7 @@ enum CheatVmOpcodeType : u32 {
/* Extended width opcodes. */
CheatVmOpcodeType_BeginRegisterConditionalBlock = 0xC0,
CheatVmOpcodeType_SaveRestoreRegister = 0xC1,
};
enum MemoryAccessType : u32 {
@ -191,6 +192,11 @@ struct BeginRegisterConditionalOpcode {
VmInt value;
};
struct SaveRestoreRegisterOpcode {
u32 dst_index;
u32 src_index;
bool is_save;
};
struct CheatVmOpcode {
CheatVmOpcodeType opcode;
@ -208,6 +214,7 @@ struct CheatVmOpcode {
PerformArithmeticRegisterOpcode perform_math_reg;
StoreRegisterToAddressOpcode str_register;
BeginRegisterConditionalOpcode begin_reg_cond;
SaveRestoreRegisterOpcode save_restore_reg;
};
};
@ -222,6 +229,7 @@ class DmntCheatVm {
bool decode_success = false;
u32 program[MaximumProgramOpcodeCount] = {0};
u64 registers[NumRegisters] = {0};
u64 saved_values[NumRegisters] = {0};
size_t loop_tops[NumRegisters] = {0};
private:
bool DecodeNextOpcode(CheatVmOpcode *out);