AVR8 opcode decoder

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2023-09-07 23:31:29 +01:00
parent d7891b386b
commit 20cbf14809
12 changed files with 2839 additions and 5 deletions

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#include "Avr8InstructionService.hpp"
namespace Services
{
using Targets::Microchip::Avr::Avr8Bit::OpcodeDecoder::Decoder;
Decoder::InstructionMapping Avr8InstructionService::fetchInstructions(
const Targets::TargetMemoryAddressRange& addressRange,
const Targets::TargetDescriptor& targetDescriptor,
TargetControllerService& targetControllerService
) {
const auto programMemory = targetControllerService.readMemory(
targetDescriptor.programMemoryType,
addressRange.startAddress,
addressRange.endAddress - addressRange.startAddress
);
return Decoder::decode(addressRange.startAddress, programMemory);
}
std::optional<Targets::TargetMemoryAddress> Avr8InstructionService::resolveProgramDestinationAddress(
const Targets::Microchip::Avr::Avr8Bit::OpcodeDecoder::Instruction& instruction,
Targets::TargetMemoryAddress instructionAddress,
const Decoder::InstructionMapping& instructions
) {
assert(instruction.canChangeProgramFlow);
if (instruction.programWordAddress.has_value()) {
return *(instruction.programWordAddress) * 2;
}
if (instruction.programWordAddressOffset.has_value()) {
return static_cast<std::int64_t>(instructionAddress) + (*(instruction.programWordAddressOffset) * 2) + 2;
}
if (instruction.canSkipNextInstruction) {
const auto subsequentInstructionAddress = instructionAddress + instruction.byteSize;
const auto subsequentInstructionIt = instructions.find(subsequentInstructionAddress);
if (subsequentInstructionIt != instructions.end() && subsequentInstructionIt->second.has_value()) {
return subsequentInstructionAddress + subsequentInstructionIt->second->byteSize;
}
}
return std::nullopt;
}
}

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#pragma once
#include "TargetControllerService.hpp"
#include "src/Targets/TargetDescriptor.hpp"
#include "src/Targets/TargetMemory.hpp"
#include "src/Targets/Microchip/AVR/AVR8/OpcodeDecoder/Instruction.hpp"
#include "src/Targets/Microchip/AVR/AVR8/OpcodeDecoder/Decoder.hpp"
namespace Services
{
class Avr8InstructionService
{
public:
/**
* Fetches opcodes from the target's program memory and attempts to decodes them.
*
* @param addressRange
* @param targetDescriptor
* @param targetControllerService
*
* @return
* A mapping of std::optional<Instruction>, mapped by their byte address in program memory. The address will
* map to std::nullopt if we failed to decode the opcode at that address.
*/
static Targets::Microchip::Avr::Avr8Bit::OpcodeDecoder::Decoder::InstructionMapping fetchInstructions(
const Targets::TargetMemoryAddressRange& addressRange,
const Targets::TargetDescriptor& targetDescriptor,
TargetControllerService& targetControllerService
);
/**
* For instructions that can change program flow, this function will attempt to figure out where, in program
* memory, the instruction may jump to.
*
* This isn't possible for instructions that perform an indirect jump, where they jump to some address stored
* in some register.
*
* This function should only be called on instructions that can change program flow
* (Instruction::canChangeProgramFlow == true).
*
* @param instruction
* The subject instruction.
*
* @param instructionAddress
* The byte address of the subject instruction.
*
* @param instructions
* A reference of the InstructionMapping from which the subject instruction was taken, which should, ideally,
* contain the subsequent instruction.
*
* We need access to the subsequent instruction in order to resolve the destination of instructions that skip
* the subsequent instruction. For example, the SBIC instruction will skip the subsequent instruction, if a
* bit in an I/O register is cleared. We can't figure out where instructions like SBIC will jump to, if we
* don't know the size of the subsequent instruction (that will be skipped).
*
* If `instructions` does not contain the subsequent instruction, we'll just return std::nullopt for
* instructions that skip the subsequent instruction.
*
* @return
* The destination byte address the subject instruction may jump to, if we were able to resolve it.
* Otherwise, std::nullopt.
*/
static std::optional<Targets::TargetMemoryAddress> resolveProgramDestinationAddress(
const Targets::Microchip::Avr::Avr8Bit::OpcodeDecoder::Instruction& instruction,
Targets::TargetMemoryAddress instructionAddress,
const Targets::Microchip::Avr::Avr8Bit::OpcodeDecoder::Decoder::InstructionMapping& instructions
);
};
}

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@@ -1,10 +1,9 @@
#pragma once
#include <string>
#include <bitset>
#include <limits>
#include <vector>
#include <numeric>
#include <cstdint>
#include <cstddef>
#include <array>
#include <type_traits>
namespace Services
{