Files
BloomPatched/src/Targets/Microchip/AVR/AVR8/Avr8.cpp

914 lines
39 KiB
C++

#include "Avr8.hpp"
#include <cassert>
#include <bitset>
#include <limits>
#include <thread>
#include "src/Logger/Logger.hpp"
#include "src/Helpers/Paths.hpp"
#include "src/Exceptions/InvalidConfig.hpp"
#include "Exceptions/DebugWirePhysicalInterfaceError.hpp"
#include "src/Targets/TargetRegister.hpp"
#include "src/Targets/Microchip/AVR/Fuse.hpp"
// Derived AVR8 targets
#include "XMega/XMega.hpp"
#include "Mega/Mega.hpp"
#include "Tiny/Tiny.hpp"
namespace Bloom::Targets::Microchip::Avr::Avr8Bit
{
using namespace Exceptions;
void Avr8::preActivationConfigure(const TargetConfig& targetConfig) {
Target::preActivationConfigure(targetConfig);
this->targetConfig = Avr8TargetConfig(targetConfig);
if (this->family.has_value()) {
this->avr8DebugInterface->setFamily(this->family.value());
} else {
if (this->targetConfig->physicalInterface == PhysicalInterface::JTAG) {
throw InvalidConfig(
"The JTAG physical interface cannot be used with an ambiguous target name"
" - please specify the exact name of the target in your configuration file. "
"See " + Paths::homeDomainName() + "/docs/supported-targets"
);
}
if (this->targetConfig->physicalInterface == PhysicalInterface::UPDI) {
throw InvalidConfig(
"The UPDI physical interface cannot be used with an ambiguous target name"
" - please specify the exact name of the target in your configuration file. "
"See " + Paths::homeDomainName() + "/docs/supported-targets"
);
}
}
if (
this->targetConfig->updateDwenFuseBit && this->avrIspInterface == nullptr
&& this->targetConfig->physicalInterface == PhysicalInterface::DEBUG_WIRE
) {
Logger::warning(
"The connected debug tool (or associated driver) does not provide any ISP interface. "
"Bloom will be unable to update the DWEN fuse bit in the event of a debugWire activation failure."
);
}
this->avr8DebugInterface->configure(this->targetConfig.value());
if (this->avrIspInterface != nullptr) {
this->avrIspInterface->configure(targetConfig);
}
}
void Avr8::postActivationConfigure() {
if (!this->targetDescriptionFile.has_value()) {
this->loadTargetDescriptionFile();
this->initFromTargetDescriptionFile();
}
/*
* The signature obtained from the device should match what is in the target description file
*
* We don't use this->getId() here as that could return the ID that was extracted from the target description
* file (which it would, if the user specified the exact target name in their project config - see
* Avr8::getId() and TargetControllerComponent::getSupportedTargets() for more).
*/
auto targetSignature = this->avr8DebugInterface->getDeviceId();
auto tdSignature = this->targetDescriptionFile->getTargetSignature();
if (targetSignature != tdSignature) {
throw Exception(
"Failed to validate connected target - target signature mismatch.\nThe target signature"
" (\"" + targetSignature.toHex() + "\") does not match the AVR8 target description signature (\""
+ tdSignature.toHex() + "\"). This will likely be due to an incorrect target name in the configuration"
+ " file (bloom.json)."
);
}
}
void Avr8::postPromotionConfigure() {
if (!this->family.has_value()) {
throw Exception("Failed to resolve AVR8 family");
}
this->avr8DebugInterface->setFamily(this->family.value());
this->avr8DebugInterface->setTargetParameters(this->targetParameters.value());
}
void Avr8::activate() {
if (this->isActivated()) {
return;
}
this->avr8DebugInterface->init();
if (this->targetDescriptionFile.has_value()) {
this->avr8DebugInterface->setTargetParameters(this->targetParameters.value());
}
try {
this->avr8DebugInterface->activate();
} catch (const Exceptions::DebugWirePhysicalInterfaceError& debugWireException) {
if (!this->targetConfig->updateDwenFuseBit) {
throw TargetOperationFailure(
"Failed to activate debugWire physical interface - check target connection and DWEN fuse "
"bit. Bloom can manage the DWEN fuse bit automatically. For instructions on enabling this "
"function, see " + Paths::homeDomainName() + "/docs/debugging-avr-debugwire"
);
}
try {
Logger::warning(
"Failed to activate the debugWire physical interface - attempting to access target via "
"the ISP interface, for DWEN fuse bit inspection."
);
this->writeDwenFuseBit(true);
// If the debug tool provides a TargetPowerManagementInterface, attempt to cycle the target power
if (
this->targetPowerManagementInterface != nullptr
&& this->targetConfig->cycleTargetPowerPostDwenUpdate
) {
Logger::info("Cycling target power");
Logger::debug("Disabling target power");
this->targetPowerManagementInterface->disableTargetPower();
Logger::debug(
"Holding power off for ~"
+ std::to_string(this->targetConfig->targetPowerCycleDelay.count())
+ " ms"
);
std::this_thread::sleep_for(this->targetConfig->targetPowerCycleDelay);
Logger::debug("Enabling target power");
this->targetPowerManagementInterface->enableTargetPower();
Logger::debug(
"Waiting ~" + std::to_string(this->targetConfig->targetPowerCycleDelay.count())
+ " ms for target power-up"
);
std::this_thread::sleep_for(this->targetConfig->targetPowerCycleDelay);
}
} catch (const Exception& exception) {
throw Exception(
"Failed to access/update DWEN fuse bit via ISP interface - " + exception.getMessage()
);
}
Logger::info("Retrying debugWire physical interface activation");
this->avr8DebugInterface->activate();
}
this->activated = true;
this->avr8DebugInterface->reset();
}
void Avr8::deactivate() {
try {
this->avr8DebugInterface->deactivate();
this->activated = false;
} catch (const Exception& exception) {
Logger::error("Failed to deactivate AVR8 target - " + exception.getMessage());
}
}
std::unique_ptr<Targets::Target> Avr8::promote() {
std::unique_ptr<Targets::Target> promoted = nullptr;
if (this->family.has_value()) {
// Promote generic AVR8 target to correct family.
switch (this->family.value()) {
case Family::XMEGA: {
Logger::info("AVR8 target promoted to XMega target");
promoted = std::make_unique<XMega>(*this);
break;
}
case Family::MEGA: {
Logger::info("AVR8 target promoted to megaAVR target");
promoted = std::make_unique<Mega>(*this);
break;
}
case Family::TINY: {
Logger::info("AVR8 target promoted to tinyAVR target");
promoted = std::make_unique<Tiny>(*this);
break;
}
default: {
break;
}
}
}
return promoted;
}
TargetDescriptor Avr8Bit::Avr8::getDescriptor() {
auto descriptor = TargetDescriptor();
descriptor.id = this->getHumanReadableId();
descriptor.name = this->getName();
descriptor.programMemoryType = Targets::TargetMemoryType::FLASH;
descriptor.registerDescriptorsByType = this->targetRegisterDescriptorsByType;
descriptor.memoryDescriptorsByType = this->targetMemoryDescriptorsByType;
std::transform(
this->targetVariantsById.begin(),
this->targetVariantsById.end(),
std::back_inserter(descriptor.variants),
[] (auto& variantToIdPair) {
return variantToIdPair.second;
}
);
return descriptor;
}
void Avr8::run() {
this->avr8DebugInterface->run();
}
void Avr8::stop() {
this->avr8DebugInterface->stop();
}
void Avr8::step() {
this->avr8DebugInterface->step();
}
void Avr8::reset() {
this->avr8DebugInterface->reset();
}
void Avr8::setBreakpoint(std::uint32_t address) {
this->avr8DebugInterface->setBreakpoint(address);
}
void Avr8::removeBreakpoint(std::uint32_t address) {
this->avr8DebugInterface->clearBreakpoint(address);
}
void Avr8::clearAllBreakpoints() {
this->avr8DebugInterface->clearAllBreakpoints();
}
void Avr8::writeRegisters(TargetRegisters registers) {
for (auto registerIt = registers.begin(); registerIt != registers.end();) {
if (registerIt->descriptor.type == TargetRegisterType::PROGRAM_COUNTER) {
auto programCounterBytes = registerIt->value;
if (programCounterBytes.size() < 4) {
// All PC register values should be at least 4 bytes in size
programCounterBytes.insert(programCounterBytes.begin(), 4 - programCounterBytes.size(), 0x00);
}
this->setProgramCounter(static_cast<std::uint32_t>(
programCounterBytes[0] << 24
| programCounterBytes[1] << 16
| programCounterBytes[2] << 8
| programCounterBytes[3]
));
registerIt = registers.erase(registerIt);
} else {
registerIt++;
}
}
if (!registers.empty()) {
this->avr8DebugInterface->writeRegisters(registers);
}
}
TargetRegisters Avr8::readRegisters(TargetRegisterDescriptors descriptors) {
TargetRegisters registers;
for (auto registerDescriptorIt = descriptors.begin(); registerDescriptorIt != descriptors.end();) {
const auto& descriptor = *registerDescriptorIt;
if (descriptor.type == TargetRegisterType::PROGRAM_COUNTER) {
registers.push_back(this->getProgramCounterRegister());
registerDescriptorIt = descriptors.erase(registerDescriptorIt);
} else {
registerDescriptorIt++;
}
}
if (!descriptors.empty()) {
auto otherRegisters = this->avr8DebugInterface->readRegisters(descriptors);
registers.insert(registers.end(), otherRegisters.begin(), otherRegisters.end());
}
return registers;
}
TargetMemoryBuffer Avr8::readMemory(
TargetMemoryType memoryType,
std::uint32_t startAddress,
std::uint32_t bytes,
const std::set<Targets::TargetMemoryAddressRange>& excludedAddressRanges
) {
return this->avr8DebugInterface->readMemory(memoryType, startAddress, bytes, excludedAddressRanges);
}
void Avr8::writeMemory(TargetMemoryType memoryType, std::uint32_t startAddress, const TargetMemoryBuffer& buffer) {
if (
memoryType == TargetMemoryType::FLASH && this->programmingSession.has_value()
&& this->targetConfig->physicalInterface != PhysicalInterface::DEBUG_WIRE
) {
if (this->targetConfig->physicalInterface == PhysicalInterface::PDI) {
const auto startSection = this->getProgramMemorySectionFromAddress(startAddress);
const auto endSection = this->getProgramMemorySectionFromAddress(
static_cast<std::uint32_t>(startAddress + buffer.size() - 1)
);
if (startSection != endSection) {
throw Exception(
"Requested program memory write spans more than one section (APPLICATION and BOOT) - aborting"
);
}
if (
!this->programmingSession->applicationSectionErased
&& (
startSection == ProgramMemorySection::APPLICATION
|| endSection == ProgramMemorySection::APPLICATION
)
) {
Logger::warning("Erasing program memory APPLICATION section, in preparation for programming");
this->avr8DebugInterface->eraseProgramMemory(ProgramMemorySection::APPLICATION);
this->programmingSession->applicationSectionErased = true;
}
if (
!this->programmingSession->bootSectionErased
&& (
startSection == ProgramMemorySection::BOOT
|| endSection == ProgramMemorySection::BOOT
)
) {
Logger::warning("Erasing program memory BOOT section, in preparation for programming");
this->avr8DebugInterface->eraseProgramMemory(ProgramMemorySection::BOOT);
this->programmingSession->bootSectionErased = true;
}
} else if (!this->programmingSession->chipErased) {
Logger::warning("Erasing entire chip, in preparation for programming");
this->avr8DebugInterface->eraseProgramMemory();
this->programmingSession->chipErased = true;
}
}
this->avr8DebugInterface->writeMemory(memoryType, startAddress, buffer);
}
TargetState Avr8::getState() {
return this->avr8DebugInterface->getTargetState();
}
std::uint32_t Avr8::getProgramCounter() {
return this->avr8DebugInterface->getProgramCounter();
}
TargetRegister Avr8::getProgramCounterRegister() {
auto programCounter = this->getProgramCounter();
return TargetRegister(TargetRegisterDescriptor(TargetRegisterType::PROGRAM_COUNTER), {
static_cast<unsigned char>(programCounter >> 24),
static_cast<unsigned char>(programCounter >> 16),
static_cast<unsigned char>(programCounter >> 8),
static_cast<unsigned char>(programCounter),
});
}
void Avr8::setProgramCounter(std::uint32_t programCounter) {
this->avr8DebugInterface->setProgramCounter(programCounter);
}
std::uint32_t Avr8::getStackPointer() {
const auto stackPointerRegister = this->readRegisters(
{this->targetRegisterDescriptorsByType.at(TargetRegisterType::STACK_POINTER)}
).front();
std::uint32_t stackPointer = 0;
for (std::size_t i = 0; i < stackPointerRegister.size() && i < 4; i++) {
stackPointer = (stackPointer << (8 * i)) | stackPointerRegister.value[i];
}
return stackPointer;
}
std::map<int, TargetPinState> Avr8::getPinStates(int variantId) {
if (!this->targetVariantsById.contains(variantId)) {
throw Exception("Invalid target variant ID");
}
std::map<int, TargetPinState> output;
auto& variant = this->targetVariantsById.at(variantId);
/*
* To prevent the number of memory reads we perform here, we cache the data and map it by start address.
*
* This way, we only perform 3 memory reads for a target variant with 3 ports - one per port (instead of one
* per pin).
*
* We may be able to make this more efficient by combining reads for ports with aligned memory addresses. This
* will be considered when the need for it becomes apparent.
*/
std::map<std::uint16_t, TargetMemoryBuffer> cachedMemoryByStartAddress;
auto readMemoryBitset = [this, &cachedMemoryByStartAddress] (std::uint16_t startAddress) {
if (!cachedMemoryByStartAddress.contains(startAddress)) {
cachedMemoryByStartAddress.insert(
std::pair(
startAddress,
this->readMemory(TargetMemoryType::RAM, startAddress, 1)
)
);
}
return std::bitset<std::numeric_limits<unsigned char>::digits>(
cachedMemoryByStartAddress.at(startAddress).at(0)
);
};
for (const auto& [pinNumber, pinDescriptor] : variant.pinDescriptorsByNumber) {
if (this->padDescriptorsByName.contains(pinDescriptor.padName)) {
auto& pad = this->padDescriptorsByName.at(pinDescriptor.padName);
if (!pad.gpioPinNumber.has_value()) {
continue;
}
auto pinState = TargetPinState();
if (pad.gpioDdrAddress.has_value()) {
const auto ddrValue = readMemoryBitset(pad.gpioDdrAddress.value());
pinState.ioDirection = ddrValue.test(pad.gpioPinNumber.value()) ?
TargetPinState::IoDirection::OUTPUT : TargetPinState::IoDirection::INPUT;
if (pinState.ioDirection == TargetPinState::IoDirection::OUTPUT
&& pad.gpioPortAddress.has_value()
) {
const auto portRegisterValueBitset = readMemoryBitset(pad.gpioPortAddress.value());
pinState.ioState = portRegisterValueBitset.test(pad.gpioPinNumber.value()) ?
TargetPinState::IoState::HIGH : TargetPinState::IoState::LOW;
} else if (pinState.ioDirection == TargetPinState::IoDirection::INPUT
&& pad.gpioPortInputAddress.has_value()
) {
const auto portInputRegisterValue = readMemoryBitset(pad.gpioPortInputAddress.value());
pinState.ioState = portInputRegisterValue.test(pad.gpioPinNumber.value()) ?
TargetPinState::IoState::HIGH : TargetPinState::IoState::LOW;
}
}
output.insert(std::pair(pinNumber, pinState));
}
}
return output;
}
void Avr8::setPinState(const TargetPinDescriptor& pinDescriptor, const TargetPinState& state) {
auto variantId = pinDescriptor.variantId;
if (!this->targetVariantsById.contains(variantId)) {
throw Exception("Invalid target variant ID");
}
if (!this->padDescriptorsByName.contains(pinDescriptor.padName)) {
throw Exception("Unknown pad");
}
if (!state.ioDirection.has_value()) {
throw Exception("Missing IO direction state");
}
const auto& variant = this->targetVariantsById.at(variantId);
const auto& padDescriptor = this->padDescriptorsByName.at(pinDescriptor.padName);
auto ioState = state.ioState;
if (state.ioDirection == TargetPinState::IoDirection::INPUT) {
// When setting the direction to INPUT, we must always set the IO pin state to LOW
ioState = TargetPinState::IoState::LOW;
}
if (
!padDescriptor.gpioDdrAddress.has_value()
|| !padDescriptor.gpioPortAddress.has_value()
|| !padDescriptor.gpioPinNumber.has_value()
) {
throw Exception("Inadequate pad descriptor");
}
const auto pinNumber = padDescriptor.gpioPinNumber.value();
const auto ddrAddress = padDescriptor.gpioDdrAddress.value();
const auto ddrValue = this->readMemory(TargetMemoryType::RAM, ddrAddress, 1);
if (ddrValue.empty()) {
throw Exception("Failed to read DDR value");
}
auto ddrValueBitset = std::bitset<std::numeric_limits<unsigned char>::digits>(ddrValue.front());
if (ddrValueBitset.test(pinNumber) != (state.ioDirection == TargetPinState::IoDirection::OUTPUT)) {
// DDR needs updating
ddrValueBitset.set(pinNumber, (state.ioDirection == TargetPinState::IoDirection::OUTPUT));
this->writeMemory(
TargetMemoryType::RAM,
ddrAddress,
{static_cast<unsigned char>(ddrValueBitset.to_ulong())}
);
}
if (ioState.has_value()) {
const auto portRegisterAddress = padDescriptor.gpioPortAddress.value();
const auto portRegisterValue = this->readMemory(TargetMemoryType::RAM, portRegisterAddress, 1);
if (portRegisterValue.empty()) {
throw Exception("Failed to read PORT register value");
}
auto portRegisterValueBitset = std::bitset<std::numeric_limits<unsigned char>::digits>(
portRegisterValue.front()
);
if (portRegisterValueBitset.test(pinNumber) != (ioState == TargetPinState::IoState::HIGH)) {
// PORT set register needs updating
portRegisterValueBitset.set(pinNumber, (ioState == TargetPinState::IoState::HIGH));
this->writeMemory(
TargetMemoryType::RAM,
portRegisterAddress,
{static_cast<unsigned char>(portRegisterValueBitset.to_ulong())}
);
}
}
}
void Avr8::enableProgrammingMode() {
this->avr8DebugInterface->enableProgrammingMode();
this->programmingSession = ProgrammingSession();
}
void Avr8::disableProgrammingMode() {
this->avr8DebugInterface->disableProgrammingMode();
this->programmingSession = std::nullopt;
}
bool Avr8::programmingModeEnabled() {
return this->programmingSession.has_value();
}
void Avr8::loadTargetDescriptionFile() {
this->targetDescriptionFile = TargetDescription::TargetDescriptionFile(
this->getId(),
(!this->name.empty()) ? std::optional(this->name) : std::nullopt
);
}
void Avr8::initFromTargetDescriptionFile() {
assert(this->targetDescriptionFile.has_value());
this->name = this->targetDescriptionFile->getTargetName();
this->family = this->targetDescriptionFile->getFamily();
this->targetParameters = this->targetDescriptionFile->getTargetParameters();
this->padDescriptorsByName = this->targetDescriptionFile->getPadDescriptorsMappedByName();
this->targetVariantsById = this->targetDescriptionFile->getVariantsMappedById();
if (!this->targetParameters->stackPointerRegisterLowAddress.has_value()) {
throw Exception(
"Failed to load sufficient AVR8 target paramters - missting stack pointer start address"
);
}
if (!this->targetParameters->statusRegisterStartAddress.has_value()) {
throw Exception(
"Failed to load sufficient AVR8 target parameters - missting status register start address"
);
}
this->loadTargetRegisterDescriptors();
this->loadTargetMemoryDescriptors();
}
void Avr8::loadTargetRegisterDescriptors() {
this->targetRegisterDescriptorsByType = this->targetDescriptionFile->getRegisterDescriptorsMappedByType();
/*
* All AVR8 targets possess 32 general purpose CPU registers. These are not described in the TDF, so we
* construct the descriptors for them here.
*/
auto gpRegisterStartAddress = this->targetParameters->gpRegisterStartAddress.value_or(0);
for (std::uint8_t i = 0; i <= 31; i++) {
auto generalPurposeRegisterDescriptor = TargetRegisterDescriptor();
generalPurposeRegisterDescriptor.startAddress = gpRegisterStartAddress + i;
generalPurposeRegisterDescriptor.size = 1;
generalPurposeRegisterDescriptor.type = TargetRegisterType::GENERAL_PURPOSE_REGISTER;
generalPurposeRegisterDescriptor.name = "r" + std::to_string(i);
generalPurposeRegisterDescriptor.groupName = "general purpose cpu";
generalPurposeRegisterDescriptor.readable = true;
generalPurposeRegisterDescriptor.writable = true;
this->targetRegisterDescriptorsByType[generalPurposeRegisterDescriptor.type].insert(
generalPurposeRegisterDescriptor
);
}
/*
* The SP and SREG registers are described in the TDF, so we could just use the descriptors extracted from the
* TDF. The problem with that is, sometimes the SP register consists of two bytes; an SPL and an SPH. These need
* to be combined into one register descriptor. This is why we just use what we already have in
* this->targetParameters.
*/
auto stackPointerRegisterDescriptor = TargetRegisterDescriptor();
stackPointerRegisterDescriptor.type = TargetRegisterType::STACK_POINTER;
stackPointerRegisterDescriptor.startAddress = this->targetParameters->stackPointerRegisterLowAddress.value();
stackPointerRegisterDescriptor.size = this->targetParameters->stackPointerRegisterSize.value();
stackPointerRegisterDescriptor.name = "SP";
stackPointerRegisterDescriptor.groupName = "CPU";
stackPointerRegisterDescriptor.description = "Stack Pointer Register";
stackPointerRegisterDescriptor.readable = true;
stackPointerRegisterDescriptor.writable = true;
auto statusRegisterDescriptor = TargetRegisterDescriptor();
statusRegisterDescriptor.type = TargetRegisterType::STATUS_REGISTER;
statusRegisterDescriptor.startAddress = this->targetParameters->statusRegisterStartAddress.value();
statusRegisterDescriptor.size = this->targetParameters->statusRegisterSize.value();
statusRegisterDescriptor.name = "SREG";
statusRegisterDescriptor.groupName = "CPU";
statusRegisterDescriptor.description = "Status Register";
statusRegisterDescriptor.readable = true;
statusRegisterDescriptor.writable = true;
auto programCounterRegisterDescriptor = TargetRegisterDescriptor();
programCounterRegisterDescriptor.type = TargetRegisterType::PROGRAM_COUNTER;
programCounterRegisterDescriptor.size = 4;
programCounterRegisterDescriptor.name = "PC";
programCounterRegisterDescriptor.groupName = "CPU";
programCounterRegisterDescriptor.description = "Program Counter";
programCounterRegisterDescriptor.readable = true;
programCounterRegisterDescriptor.writable = true;
this->targetRegisterDescriptorsByType[stackPointerRegisterDescriptor.type].insert(
stackPointerRegisterDescriptor
);
this->targetRegisterDescriptorsByType[statusRegisterDescriptor.type].insert(
statusRegisterDescriptor
);
this->targetRegisterDescriptorsByType[programCounterRegisterDescriptor.type].insert(
programCounterRegisterDescriptor
);
}
void Avr8::loadTargetMemoryDescriptors() {
const auto ramStartAddress = this->targetParameters->ramStartAddress.value();
const auto flashStartAddress = this->targetParameters->flashStartAddress.value();
this->targetMemoryDescriptorsByType.insert(std::pair(
TargetMemoryType::RAM,
TargetMemoryDescriptor(
TargetMemoryType::RAM,
TargetMemoryAddressRange(
ramStartAddress,
ramStartAddress + this->targetParameters->ramSize.value() - 1
)
)
));
this->targetMemoryDescriptorsByType.insert(std::pair(
TargetMemoryType::FLASH,
TargetMemoryDescriptor(
TargetMemoryType::FLASH,
TargetMemoryAddressRange(
flashStartAddress,
flashStartAddress + this->targetParameters->flashSize.value() - 1
),
this->targetParameters->flashPageSize
)
));
if (this->targetParameters->eepromStartAddress.has_value() && this->targetParameters->eepromSize.has_value()) {
const auto eepromStartAddress = this->targetParameters->eepromStartAddress.value();
this->targetMemoryDescriptorsByType.insert(std::pair(
TargetMemoryType::EEPROM,
TargetMemoryDescriptor(
TargetMemoryType::EEPROM,
TargetMemoryAddressRange(
eepromStartAddress,
eepromStartAddress + this->targetParameters->eepromSize.value() - 1
)
)
));
}
}
TargetSignature Avr8::getId() {
if (!this->id.has_value()) {
this->id = this->avr8DebugInterface->getDeviceId();
}
return this->id.value();
}
void Avr8::writeDwenFuseBit(bool setFuse) {
if (this->avrIspInterface == nullptr) {
throw Exception(
"Debug tool or driver does not provide access to an ISP interface - please confirm that the "
"debug tool supports ISP and then report this issue via " + Paths::homeDomainName()
+ "/report-issue"
);
}
if (!this->targetDescriptionFile.has_value() || !this->id.has_value()) {
throw Exception(
"Insufficient target information for ISP interface - do not use the generic \"avr8\" "
"target name in conjunction with the ISP interface. Please update your target configuration."
);
}
const auto& supportedPhysicalInterfaces = this->targetDescriptionFile->getSupportedDebugPhysicalInterfaces();
if (!supportedPhysicalInterfaces.contains(PhysicalInterface::DEBUG_WIRE)) {
throw Exception(
"Target does not support debugWire physical interface - check target configuration or "
"report this issue via " + Paths::homeDomainName() + "/report-issue"
);
}
const auto dwenFuseBitsDescriptor = this->targetDescriptionFile->getDwenFuseBitsDescriptor();
const auto spienFuseBitsDescriptor = this->targetDescriptionFile->getSpienFuseBitsDescriptor();
if (!dwenFuseBitsDescriptor.has_value()) {
throw Exception("Could not find DWEN bit field in TDF.");
}
if (!spienFuseBitsDescriptor.has_value()) {
throw Exception("Could not find SPIEN bit field in TDF.");
}
Logger::debug("Extracting ISP parameters from TDF");
this->avrIspInterface->setIspParameters(this->targetDescriptionFile->getIspParameters());
Logger::info("Initiating ISP interface");
this->avrIspInterface->activate();
/*
* It is crucial that we understand the potential consequences of this operation.
*
* AVR fuses are used to control certain functions within the AVR (including the debugWire interface). Care
* must be taken when updating these fuse bytes, as an incorrect value could render the AVR inaccessible to
* standard programmers.
*
* For example, consider the SPI enable (SPIEN) fuse bit. This fuse bit is used to enable/disable the SPI for
* serial programming. If the SPIEN fuse bit is cleared, most programming tools will not be able to gain access
* to the target via the SPI. This isn't too bad, if there is some other way for the programming tool to gain
* access (such as the debugWire interface). But now consider the DWEN fuse bit (which is used to enable/disable
* the debugWire interface). What if both the SPIEN *and* the DWEN fuse bits are cleared? Both interfaces will
* be disabled. Effectively, the AVR will be bricked, and the only course for recovery would be to use
* high-voltage programming.
*
* When updating the DWEN fuse, Bloom relies on data from the target description file (TDF). But there is no
* guarantee that this data is correct. For this reason, we perform additional checks in an attempt to reduce
* the likelihood of bricking the target:
*
* - Confirm target signature match - We read the AVR signature from the connected target and compare it to
* what we have in the TDF. The operation will be aborted if the signatures do not match.
*
* - SPIEN fuse bit check - we can be certain that the SPIEN fuse bit is set, because we couldn't have gotten
* this far (post ISP activation) if it wasn't. We use this axiom to verify the validity of the data in the
* TDF. If the SPIEN fuse bit appears to be cleared, we can be fairly certain that the data we have on the
* SPIEN fuse bit is incorrect. From this, we assume that the data for the DWEN fuse bit is also incorrect,
* and abort the operation.
*
* - Lock bits check - we read the lock bit byte from the target and confirm that all lock bits are cleared.
* If any lock bits are set, we abort the operation.
*
* - DWEN fuse bit check - if the DWEN fuse bit is already set to the desired value, then there is no need
* to update it. But we may be checking the wrong bit (if the TDF data is incorrect) - either way, we will
* abort the operation.
*
* The precautions described above may reduce the likelihood of Bloom bricking the connected target, but there
* is still a chance that all of the checks pass, and we still brick the device. Now would be a good time to
* remind the user of liabilities in regards to Bloom and its contributors.
*/
Logger::warning(
"Updating the DWEN fuse bit is a potentially dangerous operation. Bloom is provided \"AS IS\", "
"without warranty of any kind. You are using Bloom at your own risk. In no event shall the copyright "
"owner or contributors be liable for any damage caused as a result of using Bloom. For more details, "
"see the Bloom license at " + Paths::homeDomainName() + "/license"
);
try {
Logger::info("Reading target signature via ISP");
const auto ispDeviceId = this->avrIspInterface->getDeviceId();
if (ispDeviceId != this->id) {
throw Exception(
"AVR target signature mismatch - expected signature \"" + this->id->toHex()
+ "\" but got \"" + ispDeviceId.toHex() + "\". Please check target configuration."
);
}
Logger::info("Target signature confirmed: " + ispDeviceId.toHex());
const auto dwenFuseByte = this->avrIspInterface->readFuse(dwenFuseBitsDescriptor->fuseType).value;
const auto spienFuseByte = (spienFuseBitsDescriptor->fuseType == dwenFuseBitsDescriptor->fuseType)
? dwenFuseByte
: this->avrIspInterface->readFuse(spienFuseBitsDescriptor->fuseType).value;
/*
* Keep in mind that, for AVR fuses and lock bits, a set bit (0b1) means the fuse/lock is cleared, and a
* cleared bit (0b0), means the fuse/lock is set.
*/
if ((spienFuseByte & spienFuseBitsDescriptor->bitMask) != 0) {
/*
* If we get here, something is very wrong. The SPIEN (SPI enable) fuse bit appears to be cleared, but
* this is not possible because we're connected to the target via the SPI (the ISP interface uses a
* physical SPI between the debug tool and the target).
*
* This could be (and likely is) caused by incorrect data for the SPIEN fuse bit, in the TDF (which was
* used to construct the spienFuseBitsDescriptor). And if the data for the SPIEN fuse bit is incorrect,
* then what's to say the data for the DWEN fuse bit (dwenFuseBitsDescriptor) is any better?
*
* We must assume the worst and abort the operation. Otherwise, we risk bricking the user's hardware.
*/
throw Exception(
"Invalid SPIEN fuse bit value - suspected inaccuracies in TDF data. Please report this to "
"Bloom developers as a matter of urgency, via " + Paths::homeDomainName() + "/report-issue"
);
}
Logger::info("Current SPIEN fuse bit value confirmed");
if (static_cast<bool>(dwenFuseByte & dwenFuseBitsDescriptor->bitMask) == !setFuse) {
/*
* The DWEN fuse appears to already be set to the desired value. This may be a result of incorrect data
* in the TDF, but we're not taking any chances.
*
* We don't throw an exception here, because we don't know if this is due to an error, or if the fuse
* bit is simply already set to the desired value.
*/
Logger::debug("DWEN fuse bit already set to desired value - aborting update operation");
this->avrIspInterface->deactivate();
return;
}
const auto lockBitByte = this->avrIspInterface->readLockBitByte();
if (lockBitByte != 0xFF) {
/*
* There is at least one lock bit that is set. Setting the DWEN fuse bit with the lock bits set may
* brick the device. We must abort.
*/
throw Exception(
"At least one lock bit has been set - updating the DWEN fuse bit could potentially brick "
"the target."
);
}
Logger::info("Cleared lock bits confirmed");
const auto newFuse = Fuse(
dwenFuseBitsDescriptor->fuseType,
(setFuse) ? static_cast<unsigned char>(dwenFuseByte & ~(dwenFuseBitsDescriptor->bitMask))
: static_cast<unsigned char>(dwenFuseByte | dwenFuseBitsDescriptor->bitMask)
);
Logger::warning("Programming DWEN fuse bit");
this->avrIspInterface->programFuse(newFuse);
if (this->avrIspInterface->readFuse(dwenFuseBitsDescriptor->fuseType).value != newFuse.value) {
throw Exception("Failed to program fuse bit - post-program value check failed");
}
Logger::info("DWEN fuse bit successfully updated");
this->avrIspInterface->deactivate();
} catch (const Exception& exception) {
this->avrIspInterface->deactivate();
throw exception;
}
}
ProgramMemorySection Avr8::getProgramMemorySectionFromAddress(std::uint32_t address) {
return this->targetParameters->bootSectionStartAddress.has_value()
&& address >= this->targetParameters->bootSectionStartAddress.value()
? ProgramMemorySection::BOOT
: ProgramMemorySection::APPLICATION;
}
}