RISC-V GDB server

src/DebugServer/CMakeLists.txt

@@ -43,6 +43,20 @@ target_sources(
         ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/AvrGdb/CommandPackets/VContSupportedActionsQuery.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/AvrGdb/CommandPackets/VContRangeStep.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/AvrGdb/CommandPackets/EepromFill.cpp
+
+        # RISC-V GDB RSP Server
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/RiscVGdbRsp.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/RiscVGdbTargetDescriptor.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/CommandPackets/ReadRegisters.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/CommandPackets/ReadRegister.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/CommandPackets/WriteRegister.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/CommandPackets/ReadMemory.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/CommandPackets/WriteMemory.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/CommandPackets/ReadMemoryMap.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/CommandPackets/FlashErase.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/CommandPackets/FlashWrite.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/CommandPackets/FlashDone.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Gdb/RiscVGdb/CommandPackets/VContSupportedActionsQuery.cpp
 )
 
 if (NOT EXCLUDE_INSIGHT)

src/DebugServer/DebugServerComponent.cpp

@@ -4,6 +4,7 @@
 
 // Debug server implementations
 #include "Gdb/AvrGdb/AvrGdbRsp.hpp"
+#include "Gdb/RiscVGdb/RiscVGdbRsp.hpp"
 
 #include "src/Exceptions/InvalidConfig.hpp"
 #include "src/Logger/Logger.hpp"
@@ -55,6 +56,21 @@ namespace DebugServer
                     );
                 }
             },
+            {
+                "riscv-gdb-rsp",
+                [this] () -> std::unique_ptr<ServerInterface> {
+                    if (this->targetDescriptor.family != Targets::TargetFamily::RISC_V) {
+                        throw Exceptions::Exception{"The RISC-V GDB RSP server is only compatible with RISC-V targets."};
+                    }
+
+                    return std::make_unique<DebugServer::Gdb::RiscVGdb::RiscVGdbRsp>(
+                        this->debugServerConfig,
+                        this->targetDescriptor,
+                        *(this->eventListener.get()),
+                        this->interruptEventNotifier
+                    );
+                }
+            },
         };
     }
 

src/DebugServer/Gdb/RiscVGdb/CommandPackets/FlashDone.cpp

@@ -0,0 +1,103 @@
+#include "FlashDone.hpp"
+
+#include "src/DebugServer/Gdb/ResponsePackets/ErrorResponsePacket.hpp"
+#include "src/DebugServer/Gdb/ResponsePackets/OkResponsePacket.hpp"
+
+#include "src/Logger/Logger.hpp"
+#include "src/Exceptions/Exception.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    using Services::TargetControllerService;
+
+    using ResponsePackets::ErrorResponsePacket;
+    using ResponsePackets::OkResponsePacket;
+
+    using namespace Exceptions;
+
+    FlashDone::FlashDone(const RawPacket& rawPacket)
+        : CommandPacket(rawPacket)
+    {}
+
+    void FlashDone::handle(
+        Gdb::DebugSession& debugSession,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        const Targets::TargetDescriptor& targetDescriptor,
+        TargetControllerService& targetControllerService
+    ) {
+        Logger::info("Handling FlashDone packet");
+
+        try {
+            if (!debugSession.programmingSession.has_value()) {
+                /*
+                 * GDB will send a VFlashDone packet even it only performs an erase. In this case, there's nothing more
+                 * to do, as erase operations are executed immediately.
+                 */
+                targetControllerService.disableProgrammingMode();
+                debugSession.connection.writePacket(OkResponsePacket{});
+                return;
+            }
+
+            Logger::info(
+                "Flushing " + std::to_string(debugSession.programmingSession->buffer.size())
+                    + " bytes to target's program memory"
+            );
+
+            const auto addressRange = Targets::TargetMemoryAddressRange{
+                debugSession.programmingSession->startAddress,
+                debugSession.programmingSession->startAddress
+                    + static_cast<Targets::TargetMemorySize>(debugSession.programmingSession->buffer.size()) - 1
+            };
+
+            const auto memorySegmentDescriptors = gdbTargetDescriptor.systemAddressSpaceDescriptor.getIntersectingMemorySegmentDescriptors(
+                addressRange
+            );
+
+            if (memorySegmentDescriptors.size() != 1) {
+                throw Exception{
+                    memorySegmentDescriptors.empty()
+                        ? "Invalid command - no containing memory segments found for the given address range"
+                        : "Invalid command - address range intersects with multiple memory segments"
+                };
+            }
+
+            const auto& segmentDescriptor = *(memorySegmentDescriptors.front());
+            if (!segmentDescriptor.programmingModeAccess.writeable) {
+                throw Exception{"Memory segment (\"" + segmentDescriptor.name + "\") not writable in programming mode"};
+            }
+
+            targetControllerService.enableProgrammingMode();
+
+            targetControllerService.writeMemory(
+                gdbTargetDescriptor.systemAddressSpaceDescriptor,
+                segmentDescriptor,
+                debugSession.programmingSession->startAddress,
+                std::move(debugSession.programmingSession->buffer)
+            );
+
+            debugSession.programmingSession.reset();
+
+            Logger::warning("Program memory updated");
+            targetControllerService.disableProgrammingMode();
+
+            Logger::warning("Resetting target");
+            targetControllerService.resetTarget();
+            Logger::info("Target reset complete");
+
+            debugSession.connection.writePacket(OkResponsePacket{});
+
+        } catch (const Exception& exception) {
+            Logger::error("Failed to handle FlashDone packet - " + exception.getMessage());
+            debugSession.programmingSession.reset();
+
+            try {
+                targetControllerService.disableProgrammingMode();
+
+            } catch (const Exception& exception) {
+                Logger::error("Failed to disable programming mode - " + exception.getMessage());
+            }
+
+            debugSession.connection.writePacket(ErrorResponsePacket{});
+        }
+    }
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/FlashDone.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <cstdint>
+#include <optional>
+
+#include "RiscVGdbCommandPacketInterface.hpp"
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+
+#include "src/Targets/TargetAddressSpaceDescriptor.hpp"
+#include "src/Targets/TargetMemorySegmentDescriptor.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class FlashDone
+        : public RiscVGdbCommandPacketInterface
+        , private Gdb::CommandPackets::CommandPacket
+    {
+    public:
+        explicit FlashDone(const RawPacket& rawPacket);
+
+        void handle(
+            Gdb::DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) override;
+    };
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/FlashErase.cpp

@@ -0,0 +1,74 @@
+#include "FlashErase.hpp"
+
+#include "src/DebugServer/Gdb/ResponsePackets/ErrorResponsePacket.hpp"
+#include "src/DebugServer/Gdb/ResponsePackets/OkResponsePacket.hpp"
+
+#include "src/Services/StringService.hpp"
+#include "src/Logger/Logger.hpp"
+#include "src/Exceptions/Exception.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    using Services::TargetControllerService;
+
+    using ResponsePackets::ErrorResponsePacket;
+    using ResponsePackets::OkResponsePacket;
+
+    using namespace Exceptions;
+
+    FlashErase::FlashErase(const RawPacket& rawPacket)
+        : CommandPacket(rawPacket)
+    {
+        using Services::StringService;
+
+        if (rawPacket.size() < 8) {
+            throw Exception{"Invalid packet length"};
+        }
+
+        const auto command = std::string{this->data.begin() + 12, this->data.end()};
+
+        const auto delimiterPos = command.find_first_of(',');
+        if (delimiterPos == std::string::npos) {
+            throw Exception{"Invalid packet"};
+        }
+
+        this->startAddress = StringService::toUint32(command.substr(0, delimiterPos), 16);
+        this->bytes = StringService::toUint32(command.substr(delimiterPos + 1), 16);
+    }
+
+    void FlashErase::handle(
+        Gdb::DebugSession& debugSession,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        const Targets::TargetDescriptor& targetDescriptor,
+        TargetControllerService& targetControllerService
+    ) {
+        Logger::info("Handling FlashErase packet");
+
+        try {
+            targetControllerService.enableProgrammingMode();
+
+            Logger::warning("Erasing program memory, in preparation for programming");
+
+            // We don't erase a specific address range - we just erase the entire program memory.
+            targetControllerService.eraseMemory(
+                gdbTargetDescriptor.systemAddressSpaceDescriptor,
+                gdbTargetDescriptor.programMemorySegmentDescriptor
+            );
+
+            debugSession.connection.writePacket(OkResponsePacket{});
+
+        } catch (const Exception& exception) {
+            Logger::error("Failed to erase flash memory - " + exception.getMessage());
+            debugSession.programmingSession.reset();
+
+            try {
+                targetControllerService.disableProgrammingMode();
+
+            } catch (const Exception& exception) {
+                Logger::error("Failed to disable programming mode - " + exception.getMessage());
+            }
+
+            debugSession.connection.writePacket(ErrorResponsePacket{});
+        }
+    }
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/FlashErase.hpp

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <cstdint>
+#include <optional>
+
+#include "RiscVGdbCommandPacketInterface.hpp"
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+
+#include "src/Targets/TargetAddressSpaceDescriptor.hpp"
+#include "src/Targets/TargetMemorySegmentDescriptor.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class FlashErase
+        : public RiscVGdbCommandPacketInterface
+        , private Gdb::CommandPackets::CommandPacket
+    {
+    public:
+        std::uint32_t startAddress = 0;
+        std::uint32_t bytes = 0;
+
+        explicit FlashErase(const RawPacket& rawPacket);
+
+        void handle(
+            Gdb::DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) override;
+    };
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/FlashWrite.cpp

@@ -0,0 +1,99 @@
+#include "FlashWrite.hpp"
+
+#include "src/DebugServer/Gdb/ResponsePackets/ErrorResponsePacket.hpp"
+#include "src/DebugServer/Gdb/ResponsePackets/OkResponsePacket.hpp"
+
+#include "src/Services/StringService.hpp"
+#include "src/Logger/Logger.hpp"
+#include "src/Exceptions/Exception.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    using Services::TargetControllerService;
+
+    using ResponsePackets::ErrorResponsePacket;
+    using ResponsePackets::OkResponsePacket;
+
+    using namespace Exceptions;
+
+    FlashWrite::FlashWrite(const RawPacket& rawPacket)
+        : CommandPacket(rawPacket)
+    {
+        using Services::StringService;
+
+        if (this->data.size() < 15) {
+            throw Exception{"Invalid packet length"};
+        }
+
+        /*
+         * The flash write ('vFlashWrite') packet consists of two segments: an address and a buffer, seperated by a
+         * colon.
+         */
+        const auto delimiterIt = std::find(this->data.begin() + 12, this->data.end(), ':');
+
+        if (delimiterIt == this->data.end()) {
+            throw Exception{"Failed to find colon delimiter in write flash packet."};
+        }
+
+        this->startAddress = StringService::toUint32(std::string{this->data.begin() + 12, delimiterIt}, 16);
+        this->buffer = Targets::TargetMemoryBuffer{delimiterIt + 1, this->data.end()};
+    }
+
+    void FlashWrite::handle(
+        Gdb::DebugSession& debugSession,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        const Targets::TargetDescriptor& targetDescriptor,
+        TargetControllerService& targetControllerService
+    ) {
+        Logger::info("Handling FlashWrite packet");
+
+        try {
+            if (this->buffer.empty()) {
+                throw Exception{"Received empty buffer from GDB"};
+            }
+
+            if (!debugSession.programmingSession.has_value()) {
+                debugSession.programmingSession = ProgrammingSession{this->startAddress, this->buffer};
+
+            } else {
+                auto& programmingSession = debugSession.programmingSession.value();
+                const auto currentEndAddress = programmingSession.startAddress + programmingSession.buffer.size() - 1;
+                const auto expectedStartAddress = (currentEndAddress + 1);
+
+                if (this->startAddress < expectedStartAddress) {
+                    throw Exception{"Invalid start address from GDB - the buffer would overlap a previous buffer"};
+                }
+
+                if (this->startAddress > expectedStartAddress) {
+                    // There is a gap in the buffer sent by GDB. Fill it with 0xFF
+                    programmingSession.buffer.insert(
+                        programmingSession.buffer.end(),
+                        this->startAddress - expectedStartAddress,
+                        0xFF
+                    );
+                }
+
+                programmingSession.buffer.insert(
+                    programmingSession.buffer.end(),
+                    this->buffer.begin(),
+                    this->buffer.end()
+                );
+            }
+
+            debugSession.connection.writePacket(OkResponsePacket{});
+
+        } catch (const Exception& exception) {
+            Logger::error("Failed to handle FlashWrite packet - " + exception.getMessage());
+            debugSession.programmingSession.reset();
+
+            try {
+                targetControllerService.disableProgrammingMode();
+
+            } catch (const Exception& exception) {
+                Logger::error("Failed to disable programming mode - " + exception.getMessage());
+            }
+
+            debugSession.connection.writePacket(ErrorResponsePacket{});
+        }
+    }
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/FlashWrite.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <cstdint>
+#include <optional>
+
+#include "RiscVGdbCommandPacketInterface.hpp"
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+
+#include "src/Targets/TargetMemory.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class FlashWrite
+        : public RiscVGdbCommandPacketInterface
+        , private Gdb::CommandPackets::CommandPacket
+    {
+    public:
+        Targets::TargetMemoryAddress startAddress;
+        Targets::TargetMemoryBuffer buffer;
+
+        explicit FlashWrite(const RawPacket& rawPacket);
+
+        void handle(
+            Gdb::DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) override;
+    };
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/ReadMemory.cpp

@@ -0,0 +1,137 @@
+#include "ReadMemory.hpp"
+
+#include <cassert>
+
+#include "src/DebugServer/Gdb/ResponsePackets/ErrorResponsePacket.hpp"
+#include "src/DebugServer/Gdb/ResponsePackets/ResponsePacket.hpp"
+
+#include "src/Services/StringService.hpp"
+#include "src/Logger/Logger.hpp"
+
+#include "src/Exceptions/Exception.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    using Services::TargetControllerService;
+
+    using ResponsePackets::ErrorResponsePacket;
+    using ResponsePackets::ResponsePacket;
+
+    using Exceptions::Exception;
+
+    ReadMemory::ReadMemory(const RawPacket& rawPacket, const RiscVGdbTargetDescriptor& gdbTargetDescriptor)
+        : ReadMemory(rawPacket, gdbTargetDescriptor, ReadMemory::extractPacketData(rawPacket))
+    {}
+
+    void ReadMemory::handle(
+        Gdb::DebugSession& debugSession,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        const Targets::TargetDescriptor& targetDescriptor,
+        TargetControllerService& targetControllerService
+    ) {
+        Logger::info("Handling ReadMemory packet");
+
+        try {
+            if (this->bytes == 0) {
+                debugSession.connection.writePacket(ResponsePacket{Targets::TargetMemoryBuffer{}});
+                return;
+            }
+
+            const auto addressRange = Targets::TargetMemoryAddressRange{
+                this->startAddress,
+                this->startAddress + this->bytes - 1
+            };
+
+            const auto memorySegmentDescriptors = this->addressSpaceDescriptor.getIntersectingMemorySegmentDescriptors(
+                addressRange
+            );
+
+            /*
+             * First pass to ensure that we can read all of the memory before attempting to do so. And to ensure that
+             * the requested address range completely resides within known memory segments.
+             */
+            auto accessibleBytes = Targets::TargetMemorySize{0};
+            for (const auto* memorySegmentDescriptor : memorySegmentDescriptors) {
+                if (!memorySegmentDescriptor->debugModeAccess.readable) {
+                    throw Exception{
+                        "Attempted to access restricted memory segment (" + memorySegmentDescriptor->key
+                            + ") - segment not readable in debug mode"
+                    };
+                }
+
+                accessibleBytes += memorySegmentDescriptor->addressRange.intersectingSize(addressRange);
+            }
+
+            if (accessibleBytes < this->bytes) {
+                Logger::debug(
+                    "GDB requested access to memory which does not reside within any memory segment - returning error "
+                        "response"
+                );
+                debugSession.connection.writePacket(ErrorResponsePacket{});
+                return;
+            }
+
+            auto buffer = Targets::TargetMemoryBuffer(this->bytes, 0x00);
+
+            {
+                const auto atomicSession = targetControllerService.makeAtomicSession();
+
+                for (const auto* memorySegmentDescriptor : memorySegmentDescriptors) {
+                    const auto segmentStartAddress = std::max(
+                        this->startAddress,
+                        memorySegmentDescriptor->addressRange.startAddress
+                    );
+
+                    const auto segmentBuffer = targetControllerService.readMemory(
+                        this->addressSpaceDescriptor,
+                        *memorySegmentDescriptor,
+                        segmentStartAddress,
+                        memorySegmentDescriptor->addressRange.intersectingSize(addressRange)
+                    );
+
+                    const auto bufferOffsetIt = buffer.begin() + (segmentStartAddress - this->startAddress);
+                    assert(segmentBuffer.size() <= std::distance(bufferOffsetIt, buffer.end()));
+
+                    std::copy(segmentBuffer.begin(), segmentBuffer.end(), bufferOffsetIt);
+                }
+            }
+
+            debugSession.connection.writePacket(ResponsePacket{Services::StringService::toHex(buffer)});
+
+        } catch (const Exception& exception) {
+            Logger::error("Failed to read memory from target - " + exception.getMessage());
+            debugSession.connection.writePacket(ErrorResponsePacket{});
+        }
+    }
+
+    ReadMemory::PacketData ReadMemory::extractPacketData(const RawPacket& rawPacket) {
+        using Services::StringService;
+
+        if (rawPacket.size() < 8) {
+            throw Exception{"Invalid packet length"};
+        }
+
+        const auto command = std::string{rawPacket.begin() + 2, rawPacket.end() - 3};
+
+        const auto delimiterPos = command.find_first_of(',');
+        if (delimiterPos == std::string::npos) {
+            throw Exception{"Invalid packet"};
+        }
+
+        return {
+            .gdbStartAddress = StringService::toUint32(command.substr(0, delimiterPos), 16),
+            .bytes = StringService::toUint32(command.substr(delimiterPos + 1), 16)
+        };
+    }
+
+    ReadMemory::ReadMemory(
+        const RawPacket& rawPacket,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        ReadMemory::PacketData&& packetData
+    )
+        : CommandPacket(rawPacket)
+        , addressSpaceDescriptor(gdbTargetDescriptor.systemAddressSpaceDescriptor)
+        , startAddress(packetData.gdbStartAddress)
+        , bytes(packetData.bytes)
+    {}
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/ReadMemory.hpp

@@ -0,0 +1,47 @@
+#pragma once
+
+#include <cstdint>
+#include <optional>
+
+#include "RiscVGdbCommandPacketInterface.hpp"
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+
+#include "src/Targets/TargetAddressSpaceDescriptor.hpp"
+#include "src/Targets/TargetMemory.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class ReadMemory
+        : public RiscVGdbCommandPacketInterface
+        , private Gdb::CommandPackets::CommandPacket
+    {
+    public:
+        const Targets::TargetAddressSpaceDescriptor& addressSpaceDescriptor;
+
+        Targets::TargetMemoryAddress startAddress;
+        Targets::TargetMemorySize bytes;
+
+        ReadMemory(const RawPacket& rawPacket, const RiscVGdbTargetDescriptor& gdbTargetDescriptor);
+
+        void handle(
+            Gdb::DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) override;
+
+    private:
+        struct PacketData
+        {
+            GdbMemoryAddress gdbStartAddress;
+            std::uint32_t bytes;
+        };
+
+        static PacketData extractPacketData(const RawPacket& rawPacket);
+        ReadMemory(
+            const RawPacket& rawPacket,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            PacketData&& packetData
+        );
+    };
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/ReadMemoryMap.cpp

@@ -0,0 +1,99 @@
+#include "ReadMemoryMap.hpp"
+
+#include "src/DebugServer/Gdb/ResponsePackets/ResponsePacket.hpp"
+
+#include "src/Services/StringService.hpp"
+#include "src/Helpers/BiMap.hpp"
+#include "src/Exceptions/Exception.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    using Services::TargetControllerService;
+    using Services::StringService;
+
+    using ResponsePackets::ResponsePacket;
+
+    using Exceptions::Exception;
+
+    ReadMemoryMap::ReadMemoryMap(const RawPacket& rawPacket)
+        : CommandPacket(rawPacket)
+    {
+        if (this->data.size() < 26) {
+            throw Exception{"Invalid packet length"};
+        }
+
+        /*
+         * The read memory map ('qXfer:memory-map:read::...') packet consists of two segments, an offset and a length.
+         * These are separated by a comma character.
+         */
+        const auto command = std::string{this->data.begin() + 23, this->data.end()};
+
+        const auto delimiterPos = command.find_first_of(',');
+        if (delimiterPos == std::string::npos) {
+            throw Exception{"Invalid packet"};
+        }
+
+        this->offset = StringService::toUint32(command.substr(0, delimiterPos), 16);
+        this->length = StringService::toUint32(command.substr(delimiterPos + 1), 16);
+    }
+
+    void ReadMemoryMap::handle(
+        Gdb::DebugSession& debugSession,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        const Targets::TargetDescriptor& targetDescriptor,
+        TargetControllerService& targetControllerService
+    ) {
+        using Targets::TargetMemorySegmentType;
+
+        Logger::info("Handling ReadMemoryMap packet");
+
+        static const auto gdbMemoryTypesBySegmentType = BiMap<TargetMemorySegmentType, std::string>{
+            {TargetMemorySegmentType::FLASH, "flash"},
+            {TargetMemorySegmentType::RAM, "ram"},
+            {TargetMemorySegmentType::IO, "ram"},
+            {TargetMemorySegmentType::ALIASED, "flash"}, // TODO: Assumption made here. Will hold for now. Review later
+        };
+
+        auto memoryMap = std::string{"<memory-map>\n"};
+
+        for (const auto& [segmentKey, segmentDescriptor] : gdbTargetDescriptor.systemAddressSpaceDescriptor.segmentDescriptorsByKey) {
+            const auto gdbMemType = gdbMemoryTypesBySegmentType.valueAt(segmentDescriptor.type);
+            if (!gdbMemType.has_value()) {
+                continue;
+            }
+
+            const auto segmentWritable = (
+                segmentDescriptor.debugModeAccess.writeable
+                || segmentDescriptor.programmingModeAccess.writeable
+            );
+
+            memoryMap += "<memory type=\"" + (!segmentWritable ? "rom" : *gdbMemType) + "\" start=\"0x"
+                + StringService::toHex(segmentDescriptor.addressRange.startAddress) + "\" length=\""
+                + std::to_string(segmentDescriptor.size()) + "\"";
+
+            if (segmentWritable && segmentDescriptor.pageSize.has_value()) {
+                memoryMap += ">\n    <property name=\"blocksize\">" + std::to_string(*(segmentDescriptor.pageSize))
+                    + "</property>\n</memory>\n";
+            } else {
+                memoryMap += "/>\n";
+            }
+        }
+
+        memoryMap += "</memory-map>";
+
+        auto responseData = std::vector<unsigned char>{'l'};
+
+        if (this->offset < memoryMap.size() && this->length > 0) {
+            responseData.insert(
+                responseData.end(),
+                memoryMap.begin() + this->offset,
+                memoryMap.begin() + this->offset + std::min(
+                    static_cast<long>(this->length),
+                    static_cast<long>(memoryMap.size() - this->offset)
+                )
+            );
+        }
+
+        debugSession.connection.writePacket(ResponsePacket{responseData});
+    }
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/ReadMemoryMap.hpp

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <cstdint>
+
+#include "RiscVGdbCommandPacketInterface.hpp"
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+
+#include "src/Targets/TargetAddressSpaceDescriptor.hpp"
+#include "src/Targets/TargetMemorySegmentDescriptor.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class ReadMemoryMap
+        : public RiscVGdbCommandPacketInterface
+        , private Gdb::CommandPackets::CommandPacket
+    {
+    public:
+        /**
+         * The offset of the memory map, from which to read.
+         */
+        std::uint32_t offset = 0;
+
+        /**
+         * The length of the memory map to read.
+         */
+        std::uint32_t length = 0;
+
+        explicit ReadMemoryMap(const RawPacket& rawPacket);
+
+        void handle(
+            Gdb::DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) override;
+    };
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/ReadRegister.cpp

@@ -0,0 +1,95 @@
+#include "ReadRegister.hpp"
+
+#include "src/DebugServer/Gdb/ResponsePackets/ErrorResponsePacket.hpp"
+
+#include "src/Targets/TargetRegisterDescriptor.hpp"
+
+#include "src/Services/StringService.hpp"
+#include "src/Logger/Logger.hpp"
+
+#include "src/Exceptions/Exception.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    using Services::TargetControllerService;
+
+    using Targets::TargetRegisterDescriptors;
+
+    using ResponsePackets::ResponsePacket;
+    using ResponsePackets::ErrorResponsePacket;
+
+    using Exceptions::Exception;
+
+    ReadRegister::ReadRegister(const RawPacket& rawPacket)
+        : CommandPacket(rawPacket)
+    {
+        using Services::StringService;
+
+        if (this->data.size() < 2) {
+            throw Exception{"Invalid packet length"};
+        }
+
+        this->registerId = static_cast<GdbRegisterId>(
+            StringService::toUint32(std::string{this->data.begin() + 1, this->data.end()}, 16)
+        );
+    }
+
+    void ReadRegister::handle(
+        Gdb::DebugSession& debugSession,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        const Targets::TargetDescriptor& targetDescriptor,
+        TargetControllerService& targetControllerService
+    ) {
+        Logger::info("Handling ReadRegister packet");
+
+        try {
+            Logger::debug("Reading GDB register ID: " + std::to_string(this->registerId));
+
+            if (this->registerId == gdbTargetDescriptor.programCounterGdbRegisterId) {
+                /*
+                 * GDB has requested the program counter. We can't access this in the same way as we do with other
+                 * registers.
+                 */
+                const auto programCounter = targetControllerService.getProgramCounter();
+
+                debugSession.connection.writePacket(
+                    ResponsePacket{Services::StringService::toHex(Targets::TargetMemoryBuffer{
+                        static_cast<unsigned char>(programCounter),
+                        static_cast<unsigned char>(programCounter >> 8),
+                        static_cast<unsigned char>(programCounter >> 16),
+                        static_cast<unsigned char>(programCounter >> 24),
+                    })}
+                );
+
+                return;
+            }
+
+            const auto gdbRegisterDescriptorIt = gdbTargetDescriptor.gdbRegisterDescriptorsById.find(this->registerId);
+            const auto targetRegisterDescriptorIt = gdbTargetDescriptor.targetRegisterDescriptorsByGdbId.find(
+                this->registerId
+            );
+
+            if (
+                gdbRegisterDescriptorIt == gdbTargetDescriptor.gdbRegisterDescriptorsById.end()
+                || targetRegisterDescriptorIt == gdbTargetDescriptor.targetRegisterDescriptorsByGdbId.end()
+            ) {
+                throw Exception{"Unknown GDB register ID (" + std::to_string(this->registerId) + ")"};
+            }
+
+            auto registerValue = targetControllerService.readRegister(*(targetRegisterDescriptorIt->second));
+            std::reverse(registerValue.begin(), registerValue.end()); // MSB to LSB
+
+            const auto& gdbRegisterDescriptor = gdbRegisterDescriptorIt->second;
+            if (registerValue.size() < gdbRegisterDescriptor.size) {
+                // The register on the target is smaller than the size expected by GDB.
+                registerValue.insert(registerValue.end(), (gdbRegisterDescriptor.size - registerValue.size()), 0x00);
+            }
+
+            debugSession.connection.writePacket(ResponsePacket{Services::StringService::toHex(registerValue)});
+
+        } catch (const Exception& exception) {
+            Logger::error("Failed to read general registers - " + exception.getMessage());
+            debugSession.connection.writePacket(ErrorResponsePacket{});
+        }
+    }
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/ReadRegister.hpp

@@ -0,0 +1,26 @@
+#pragma once
+
+#include "RiscVGdbCommandPacketInterface.hpp"
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+
+#include "src/DebugServer/Gdb/RegisterDescriptor.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class ReadRegister
+        : public RiscVGdbCommandPacketInterface
+        , private Gdb::CommandPackets::CommandPacket
+    {
+    public:
+        GdbRegisterId registerId;
+
+        explicit ReadRegister(const RawPacket& rawPacket);
+
+        void handle(
+            Gdb::DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) override;
+    };
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/ReadRegisters.cpp

@@ -0,0 +1,81 @@
+#include "ReadRegisters.hpp"
+
+#include <algorithm>
+#include <iterator>
+#include <cassert>
+
+#include "src/DebugServer/Gdb/ResponsePackets/ErrorResponsePacket.hpp"
+
+#include "src/Targets/TargetRegisterDescriptor.hpp"
+#include "src/Targets/TargetMemory.hpp"
+
+#include "src/Logger/Logger.hpp"
+
+#include "src/Exceptions/Exception.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    using Services::TargetControllerService;
+
+    using ResponsePackets::ResponsePacket;
+    using ResponsePackets::ErrorResponsePacket;
+
+    using Exceptions::Exception;
+
+    ReadRegisters::ReadRegisters(const RawPacket& rawPacket)
+        : CommandPacket(rawPacket)
+    {}
+
+    void ReadRegisters::handle(
+        Gdb::DebugSession& debugSession,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        const Targets::TargetDescriptor& targetDescriptor,
+        TargetControllerService& targetControllerService
+    ) {
+        Logger::info("Handling ReadRegisters packet");
+
+        try {
+            const auto totalRegBytes = gdbTargetDescriptor.targetRegisterDescriptorsByGdbId.size() * 4;
+            auto buffer = Targets::TargetMemoryBuffer(totalRegBytes, 0x00);
+
+            auto gpRegDescriptors = Targets::TargetRegisterDescriptors{};
+            std::transform(
+                gdbTargetDescriptor.targetRegisterDescriptorsByGdbId.begin(),
+                gdbTargetDescriptor.targetRegisterDescriptorsByGdbId.end(),
+                std::back_inserter(gpRegDescriptors),
+                [] (const auto& pair) {
+                    return pair.second;
+                }
+            );
+
+            {
+                const auto atomicSession = targetControllerService.makeAtomicSession();
+
+                for (auto& [regDesc, regVal] : targetControllerService.readRegisters(gpRegDescriptors)) {
+                    const auto bufferOffset = (
+                        regDesc.startAddress - gdbTargetDescriptor.gpRegistersMemorySegmentDescriptor.addressRange.startAddress
+                    ) * gdbTargetDescriptor.gpRegistersMemorySegmentDescriptor.addressSpaceUnitSize;
+
+                    assert((buffer.size() - bufferOffset) >= regVal.size());
+
+                    /*
+                     * GDB expects register values in LSB form, which is why we use reverse iterators below.
+                     */
+                    std::copy(regVal.rbegin(), regVal.rend(), buffer.begin() + bufferOffset);
+                }
+
+                const auto pcValue = targetControllerService.getProgramCounter();
+                buffer[totalRegBytes - 4] = static_cast<unsigned char>(pcValue);
+                buffer[totalRegBytes - 3] = static_cast<unsigned char>(pcValue >> 8);
+                buffer[totalRegBytes - 2] = static_cast<unsigned char>(pcValue >> 16);
+                buffer[totalRegBytes - 1] = static_cast<unsigned char>(pcValue >> 24);
+            }
+
+            debugSession.connection.writePacket(ResponsePacket{Services::StringService::toHex(buffer)});
+
+        } catch (const Exception& exception) {
+            Logger::error("Failed to read registers - " + exception.getMessage());
+            debugSession.connection.writePacket(ErrorResponsePacket{});
+        }
+    }
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/ReadRegisters.hpp

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <optional>
+
+#include "RiscVGdbCommandPacketInterface.hpp"
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+
+#include "src/DebugServer/Gdb/RegisterDescriptor.hpp"
+#include "src/Targets/TargetMemorySegmentDescriptor.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class ReadRegisters
+        : public RiscVGdbCommandPacketInterface
+        , private Gdb::CommandPackets::CommandPacket
+    {
+    public:
+        explicit ReadRegisters(const RawPacket& rawPacket);
+
+        void handle(
+            Gdb::DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) override;
+    };
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/RiscVGdbCommandPacketInterface.hpp

@@ -0,0 +1,31 @@
+#pragma once
+
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+#include "src/DebugServer/Gdb/DebugSession.hpp"
+#include "src/DebugServer/Gdb/RiscVGdb/RiscVGdbTargetDescriptor.hpp"
+#include "src/Targets/TargetDescriptor.hpp"
+#include "src/Services/TargetControllerService.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class RiscVGdbCommandPacketInterface
+    {
+    public:
+        virtual ~RiscVGdbCommandPacketInterface() = default;
+
+        /**
+         * Should handle the command for the current active debug session.
+         *
+         * @param debugSession
+         *  The current active debug session.
+         *
+         * @param TargetControllerService
+         */
+        virtual void handle(
+            DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) = 0;
+    };
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/VContSupportedActionsQuery.cpp

@@ -0,0 +1,24 @@
+#include "VContSupportedActionsQuery.hpp"
+
+#include "src/DebugServer/Gdb/ResponsePackets/ResponsePacket.hpp"
+
+#include "src/Logger/Logger.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    using Services::TargetControllerService;
+
+    VContSupportedActionsQuery::VContSupportedActionsQuery(const RawPacket& rawPacket)
+        : CommandPacket(rawPacket)
+    {}
+
+    void VContSupportedActionsQuery::handle(
+        Gdb::DebugSession& debugSession,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        const Targets::TargetDescriptor& targetDescriptor,
+        TargetControllerService& targetControllerService
+    ) {
+        Logger::info("Handling VContSupportedActionsQuery packet");
+        debugSession.connection.writePacket(ResponsePackets::ResponsePacket{"vCont;c;C;s;S"});
+    }
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/VContSupportedActionsQuery.hpp

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <string>
+#include <set>
+
+#include "RiscVGdbCommandPacketInterface.hpp"
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class VContSupportedActionsQuery
+        : public RiscVGdbCommandPacketInterface
+        , private Gdb::CommandPackets::CommandPacket
+    {
+    public:
+        explicit VContSupportedActionsQuery(const RawPacket& rawPacket);
+
+        void handle(
+            Gdb::DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) override;
+    };
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/WriteMemory.cpp

@@ -0,0 +1,132 @@
+#include "WriteMemory.hpp"
+
+#include "src/DebugServer/Gdb/ResponsePackets/ErrorResponsePacket.hpp"
+#include "src/DebugServer/Gdb/ResponsePackets/OkResponsePacket.hpp"
+
+#include "src/Services/StringService.hpp"
+#include "src/Logger/Logger.hpp"
+#include "src/Exceptions/Exception.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    using Services::TargetControllerService;
+
+    using ResponsePackets::ErrorResponsePacket;
+    using ResponsePackets::OkResponsePacket;
+
+    using namespace Exceptions;
+
+    WriteMemory::WriteMemory(const RawPacket& rawPacket, const RiscVGdbTargetDescriptor& gdbTargetDescriptor)
+        : WriteMemory(rawPacket, gdbTargetDescriptor, WriteMemory::extractPacketData(rawPacket))
+    {}
+
+    void WriteMemory::handle(
+        Gdb::DebugSession& debugSession,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        const Targets::TargetDescriptor& targetDescriptor,
+        TargetControllerService& targetControllerService
+    ) {
+        Logger::info("Handling WriteMemory packet");
+
+        try {
+            if (this->buffer.empty()) {
+                debugSession.connection.writePacket(OkResponsePacket{});
+                return;
+            }
+
+            const auto& systemAddressSpaceDescriptor = gdbTargetDescriptor.systemAddressSpaceDescriptor;
+            const auto addressRange = Targets::TargetMemoryAddressRange{
+                this->startAddress,
+                this->startAddress + static_cast<Targets::TargetMemorySize>(this->buffer.size()) - 1
+            };
+
+            const auto memorySegmentDescriptors = systemAddressSpaceDescriptor.getIntersectingMemorySegmentDescriptors(
+                addressRange
+            );
+
+            auto accessibleBytes = Targets::TargetMemorySize{0};
+            for (const auto* memorySegmentDescriptor : memorySegmentDescriptors) {
+                if (!memorySegmentDescriptor->debugModeAccess.writeable) {
+                    throw Exception{
+                        "Attempted to access restricted memory segment (" + memorySegmentDescriptor->key
+                            + ") - segment not writeable in debug mode"
+                    };
+                }
+
+                accessibleBytes += memorySegmentDescriptor->addressRange.intersectingSize(addressRange);
+            }
+
+            if (accessibleBytes < this->bytes) {
+                throw Exception{"GDB requested access to memory which does not reside within any memory segment"};
+            }
+
+            {
+                const auto atomicSession = targetControllerService.makeAtomicSession();
+
+                for (const auto* memorySegmentDescriptor : memorySegmentDescriptors) {
+                    const auto segmentStartAddress = std::max(
+                        this->startAddress,
+                        memorySegmentDescriptor->addressRange.startAddress
+                    );
+
+                    const auto bufferOffsetIt = buffer.begin() + (segmentStartAddress - this->startAddress);
+                    targetControllerService.writeMemory(
+                        systemAddressSpaceDescriptor,
+                        *memorySegmentDescriptor,
+                        segmentStartAddress,
+                        Targets::TargetMemoryBuffer{
+                            bufferOffsetIt,
+                            bufferOffsetIt + memorySegmentDescriptor->addressRange.intersectingSize(addressRange)
+                        }
+                    );
+                }
+            }
+
+            debugSession.connection.writePacket(OkResponsePacket{});
+
+        } catch (const Exception& exception) {
+            Logger::error("Failed to write memory to target - " + exception.getMessage());
+            debugSession.connection.writePacket(ErrorResponsePacket{});
+        }
+    }
+
+    WriteMemory::PacketData WriteMemory::extractPacketData(const RawPacket& rawPacket) {
+        using Services::StringService;
+
+        if (rawPacket.size() < 8) {
+            throw Exception{"Invalid packet length"};
+        }
+
+        const auto command = std::string{rawPacket.begin() + 2, rawPacket.end() - 3};
+
+        const auto commaDelimiterPos = command.find_first_of(',');
+        const auto colonDelimiterPos = command.find_first_of(':');
+        if (commaDelimiterPos == std::string::npos || colonDelimiterPos == std::string::npos) {
+            throw Exception{"Invalid packet"};
+        }
+
+        return {
+            .gdbStartAddress = StringService::toUint32(command.substr(0, commaDelimiterPos), 16),
+            .bytes = StringService::toUint32(
+                command.substr(commaDelimiterPos + 1, colonDelimiterPos - (commaDelimiterPos + 1)),
+                16
+            ),
+            .buffer = StringService::dataFromHex(command.substr(colonDelimiterPos + 1))
+        };
+    }
+
+    WriteMemory::WriteMemory(
+        const RawPacket& rawPacket,
+        const RiscVGdbTargetDescriptor&,
+        PacketData&& packetData
+    )
+        : CommandPacket(rawPacket)
+        , startAddress(packetData.gdbStartAddress)
+        , bytes(packetData.bytes)
+        , buffer(std::move(packetData.buffer))
+    {
+        if (this->buffer.size() != this->bytes) {
+            throw Exception{"Buffer size does not match length value given in write memory packet"};
+        }
+    }
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/WriteMemory.hpp

@@ -0,0 +1,42 @@
+#pragma once
+
+#include <cstdint>
+#include <optional>
+
+#include "RiscVGdbCommandPacketInterface.hpp"
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+
+#include "src/Targets/TargetMemory.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class WriteMemory
+        : public RiscVGdbCommandPacketInterface
+        , private Gdb::CommandPackets::CommandPacket
+    {
+    public:
+        Targets::TargetMemoryAddress startAddress;
+        Targets::TargetMemorySize bytes;
+        Targets::TargetMemoryBuffer buffer;
+
+        explicit WriteMemory(const RawPacket& rawPacket, const RiscVGdbTargetDescriptor& gdbTargetDescriptor);
+
+        void handle(
+            Gdb::DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) override;
+
+    private:
+        struct PacketData
+        {
+            GdbMemoryAddress gdbStartAddress;
+            std::uint32_t bytes;
+            Targets::TargetMemoryBuffer buffer;
+        };
+
+        static PacketData extractPacketData(const RawPacket& rawPacket);
+        WriteMemory(const RawPacket& rawPacket, const RiscVGdbTargetDescriptor& gdbTargetDescriptor, PacketData&& packetData);
+    };
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/WriteRegister.cpp

@@ -0,0 +1,94 @@
+#include "WriteRegister.hpp"
+
+#include "src/DebugServer/Gdb/ResponsePackets/OkResponsePacket.hpp"
+#include "src/DebugServer/Gdb/ResponsePackets/ErrorResponsePacket.hpp"
+
+#include "src/Services/StringService.hpp"
+#include "src/Logger/Logger.hpp"
+#include "src/Exceptions/Exception.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    using Services::TargetControllerService;
+
+    using ResponsePackets::ResponsePacket;
+    using ResponsePackets::OkResponsePacket;
+    using ResponsePackets::ErrorResponsePacket;
+
+    using Exceptions::Exception;
+
+    WriteRegister::WriteRegister(const RawPacket& rawPacket)
+        : CommandPacket(rawPacket)
+    {
+        using Services::StringService;
+
+        if (this->data.size() < 4) {
+            throw Exception{"Invalid WriteRegister command packet - insufficient data in packet."};
+        }
+
+        // The P packet updates a single register
+        auto command = std::string{this->data.begin() + 1, this->data.end()};
+
+        const auto delimiterPos = command.find_first_of('=');
+        if (delimiterPos == std::string::npos) {
+            throw Exception{"Invalid packet"};
+        }
+
+        this->registerId = static_cast<GdbRegisterId>(StringService::toUint32(command.substr(0, delimiterPos), 16));
+        this->registerValue = Services::StringService::dataFromHex(command.substr(delimiterPos + 1));
+
+        if (this->registerValue.empty()) {
+            throw Exception{"Invalid WriteRegister command packet - missing register value"};
+        }
+
+        // LSB to MSB
+        std::reverse(this->registerValue.begin(), this->registerValue.end());
+    }
+
+    void WriteRegister::handle(
+        Gdb::DebugSession& debugSession,
+        const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+        const Targets::TargetDescriptor& targetDescriptor,
+        TargetControllerService& targetControllerService
+    ) {
+        Logger::info("Handling WriteRegister packet");
+
+        try {
+            if (this->registerId == gdbTargetDescriptor.programCounterGdbRegisterId) {
+                if (this->registerValue.size() != 4) {
+                    throw Exception{"Invalid PC value register size"};
+                }
+
+                targetControllerService.setProgramCounter(
+                    static_cast<Targets::TargetMemoryAddress>(
+                        this->registerValue[0] << 24
+                        | this->registerValue[1] << 16
+                        | this->registerValue[2] << 8
+                        | this->registerValue[3]
+                    )
+                );
+
+                debugSession.connection.writePacket(OkResponsePacket{});
+                return;
+            }
+
+            const auto gdbRegisterDescriptorIt = gdbTargetDescriptor.gdbRegisterDescriptorsById.find(this->registerId);
+            const auto targetRegisterDescriptorIt = gdbTargetDescriptor.targetRegisterDescriptorsByGdbId.find(
+                this->registerId
+            );
+            if (
+                gdbRegisterDescriptorIt == gdbTargetDescriptor.gdbRegisterDescriptorsById.end()
+                || targetRegisterDescriptorIt == gdbTargetDescriptor.targetRegisterDescriptorsByGdbId.end()
+            ) {
+                throw Exception{"Unknown GDB register ID (" + std::to_string(this->registerId) + ")"};
+            }
+
+            targetControllerService.writeRegister(*(targetRegisterDescriptorIt->second), this->registerValue);
+            debugSession.connection.writePacket(OkResponsePacket{});
+
+        } catch (const Exception& exception) {
+            Logger::error("Failed to write registers - " + exception.getMessage());
+            debugSession.connection.writePacket(ErrorResponsePacket{});
+        }
+    }
+}

src/DebugServer/Gdb/RiscVGdb/CommandPackets/WriteRegister.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "RiscVGdbCommandPacketInterface.hpp"
+#include "src/DebugServer/Gdb/CommandPackets/CommandPacket.hpp"
+
+#include "src/DebugServer/Gdb/RegisterDescriptor.hpp"
+
+#include "src/Targets/TargetMemory.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb::CommandPackets
+{
+    class WriteRegister
+        : public RiscVGdbCommandPacketInterface
+        , private Gdb::CommandPackets::CommandPacket
+    {
+    public:
+        GdbRegisterId registerId;
+        Targets::TargetMemoryBuffer registerValue;
+
+        explicit WriteRegister(const RawPacket& rawPacket);
+
+        void handle(
+            Gdb::DebugSession& debugSession,
+            const RiscVGdbTargetDescriptor& gdbTargetDescriptor,
+            const Targets::TargetDescriptor& targetDescriptor,
+            Services::TargetControllerService& targetControllerService
+        ) override;
+    };
+}

src/DebugServer/Gdb/RiscVGdb/RiscVGdbRsp.cpp

@@ -0,0 +1,135 @@
+#include "RiscVGdbRsp.hpp"
+
+#include "src/Services/StringService.hpp"
+
+// Command packets
+#include "CommandPackets/ReadRegister.hpp"
+#include "CommandPackets/ReadRegisters.hpp"
+#include "CommandPackets/WriteRegister.hpp"
+#include "CommandPackets/ReadMemory.hpp"
+#include "CommandPackets/WriteMemory.hpp"
+#include "CommandPackets/ReadMemoryMap.hpp"
+#include "CommandPackets/FlashErase.hpp"
+#include "CommandPackets/FlashWrite.hpp"
+#include "CommandPackets/FlashDone.hpp"
+#include "CommandPackets/VContSupportedActionsQuery.hpp"
+
+#include "src/DebugServer/Gdb/CommandPackets/Monitor.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb
+{
+    using namespace Exceptions;
+
+    using Targets::TargetRegisterDescriptor;
+    using Targets::TargetRegisterType;
+
+    RiscVGdbRsp::RiscVGdbRsp(
+        const DebugServerConfig& debugServerConfig,
+        const Targets::TargetDescriptor& targetDescriptor,
+        EventListener& eventListener,
+        EventFdNotifier& eventNotifier
+    )
+        : GdbRspDebugServer(
+            debugServerConfig,
+            targetDescriptor,
+            RiscVGdbTargetDescriptor{targetDescriptor},
+            eventListener,
+            eventNotifier
+        )
+    {}
+
+    std::string RiscVGdbRsp::getName() const {
+        return "RISC-V GDB RSP Server";
+    }
+
+    std::unique_ptr<CommandPackets::RiscVGdbCommandPacketInterface> RiscVGdbRsp::rawPacketToCommandPacket(
+        const RawPacket& rawPacket
+    ) {
+        using Gdb::CommandPackets::Monitor;
+
+        using CommandPackets::ReadRegister;
+        using CommandPackets::ReadRegisters;
+        using CommandPackets::WriteRegister;
+        using CommandPackets::ReadMemory;
+        using CommandPackets::WriteMemory;
+        using CommandPackets::ReadMemoryMap;
+        using CommandPackets::FlashErase;
+        using CommandPackets::FlashWrite;
+        using CommandPackets::FlashDone;
+        using CommandPackets::VContSupportedActionsQuery;
+
+        if (rawPacket.size() < 2) {
+            throw ::Exceptions::Exception{"Invalid raw packet - no data"};
+        }
+
+        if (rawPacket[1] == 'p') {
+            return std::make_unique<ReadRegister>(rawPacket);
+        }
+
+        if (rawPacket[1] == 'g') {
+            return std::make_unique<ReadRegisters>(rawPacket);
+        }
+
+        if (rawPacket[1] == 'P') {
+            return std::make_unique<WriteRegister>(rawPacket);
+        }
+
+        if (rawPacket[1] == 'm') {
+            return std::make_unique<ReadMemory>(rawPacket, this->gdbTargetDescriptor);
+        }
+
+        if (rawPacket[1] == 'M') {
+            return std::make_unique<WriteMemory>(rawPacket, this->gdbTargetDescriptor);
+        }
+
+        if (rawPacket.size() > 1) {
+            const auto rawPacketString = std::string{rawPacket.begin() + 1, rawPacket.end()};
+
+            if (rawPacketString.find("qXfer:memory-map:read::") == 0) {
+                return std::make_unique<ReadMemoryMap>(rawPacket);
+            }
+
+            if (rawPacketString.find("vFlashErase") == 0) {
+                return std::make_unique<FlashErase>(rawPacket);
+            }
+
+            if (rawPacketString.find("vFlashWrite") == 0) {
+                return std::make_unique<FlashWrite>(rawPacket);
+            }
+
+            if (rawPacketString.find("vFlashDone") == 0) {
+                return std::make_unique<FlashDone>(rawPacket);
+            }
+
+            if (rawPacketString.find("vCont?") == 0) {
+                return std::make_unique<VContSupportedActionsQuery>(rawPacket);
+            }
+        }
+
+        return nullptr;
+    }
+
+    std::set<std::pair<Feature, std::optional<std::string>>> RiscVGdbRsp::getSupportedFeatures() {
+        auto output = std::set<std::pair<Feature, std::optional<std::string>>>{
+            {Feature::HARDWARE_BREAKPOINTS, std::nullopt},
+            {Feature::SOFTWARE_BREAKPOINTS, std::nullopt},
+            {Feature::MEMORY_MAP_READ, std::nullopt},
+            {Feature::VCONT_ACTIONS_QUERY, std::nullopt},
+        };
+
+        if (!this->debugServerConfig.packetAcknowledgement) {
+            output.emplace(Feature::NO_ACK_MODE, std::nullopt);
+        }
+
+        return output;
+    }
+
+    void RiscVGdbRsp::handleTargetStoppedGdbResponse(Targets::TargetMemoryAddress programAddress) {
+        using Services::StringService;
+
+        Logger::debug("Target stopped at byte address: 0x" + StringService::toHex(programAddress));
+
+        // Report the stop to GDB
+        return GdbRspDebugServer::handleTargetStoppedGdbResponse(programAddress);
+    }
+}

src/DebugServer/Gdb/RiscVGdb/RiscVGdbRsp.hpp

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <cstdint>
+
+#include "src/DebugServer/Gdb/GdbRspDebugServer.hpp"
+#include "RiscVGdbTargetDescriptor.hpp"
+#include "CommandPackets/RiscVGdbCommandPacketInterface.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb
+{
+    class RiscVGdbRsp
+        : public GdbRspDebugServer<
+            RiscVGdbTargetDescriptor,
+            DebugSession,
+            CommandPackets::RiscVGdbCommandPacketInterface
+        >
+    {
+    public:
+        RiscVGdbRsp(
+            const DebugServerConfig& debugServerConfig,
+            const Targets::TargetDescriptor& targetDescriptor,
+            EventListener& eventListener,
+            EventFdNotifier& eventNotifier
+        );
+
+        std::string getName() const override;
+
+    protected:
+        std::unique_ptr<CommandPackets::RiscVGdbCommandPacketInterface> rawPacketToCommandPacket(
+            const RawPacket& rawPacket
+        ) override;
+        std::set<std::pair<Feature, std::optional<std::string>>> getSupportedFeatures() override;
+        void handleTargetStoppedGdbResponse(Targets::TargetMemoryAddress programAddress) override;
+    };
+}

src/DebugServer/Gdb/RiscVGdb/RiscVGdbTargetDescriptor.cpp

@@ -0,0 +1,40 @@
+#include "RiscVGdbTargetDescriptor.hpp"
+
+#include "src/Exceptions/Exception.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb
+{
+    using Targets::TargetRegisterDescriptor;
+    using Targets::TargetRegisterType;
+
+    using Exceptions::Exception;
+
+    RiscVGdbTargetDescriptor::RiscVGdbTargetDescriptor(const Targets::TargetDescriptor& targetDescriptor)
+        : systemAddressSpaceDescriptor(targetDescriptor.getAddressSpaceDescriptor("system"))
+        , cpuAddressSpaceDescriptor(targetDescriptor.getAddressSpaceDescriptor("debug_module"))
+        , programMemorySegmentDescriptor(this->systemAddressSpaceDescriptor.getMemorySegmentDescriptor("internal_program_memory"))
+        , gpRegistersMemorySegmentDescriptor(this->cpuAddressSpaceDescriptor.getMemorySegmentDescriptor("gp_registers"))
+        , cpuGpPeripheralDescriptor(targetDescriptor.getPeripheralDescriptor("cpu"))
+        , cpuGpRegisterGroupDescriptor(this->cpuGpPeripheralDescriptor.getRegisterGroupDescriptor("gpr"))
+        , programCounterGdbRegisterId(static_cast<GdbRegisterId>(this->cpuGpRegisterGroupDescriptor.registerDescriptorsByKey.size()))
+    {
+        // Create the GDB register descriptors and populate the mappings for the general purpose registers (ID 0->31)
+        for (const auto& [key, descriptor] : this->cpuGpRegisterGroupDescriptor.registerDescriptorsByKey) {
+            if (descriptor.type != TargetRegisterType::GENERAL_PURPOSE_REGISTER) {
+                continue;
+            }
+
+            const auto gdbRegisterId = static_cast<GdbRegisterId>(
+                descriptor.startAddress - this->gpRegistersMemorySegmentDescriptor.addressRange.startAddress
+            );
+
+            this->gdbRegisterDescriptorsById.emplace(gdbRegisterId, RegisterDescriptor{gdbRegisterId, 4});
+            this->targetRegisterDescriptorsByGdbId.emplace(gdbRegisterId, &descriptor);
+        }
+
+        this->gdbRegisterDescriptorsById.emplace(
+            this->programCounterGdbRegisterId,
+            RegisterDescriptor{this->programCounterGdbRegisterId, 4}
+        );
+    }
+}

src/DebugServer/Gdb/RiscVGdb/RiscVGdbTargetDescriptor.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "src/DebugServer/Gdb/TargetDescriptor.hpp"
+
+#include "src/Targets/TargetDescriptor.hpp"
+#include "src/Targets/TargetAddressSpaceDescriptor.hpp"
+#include "src/Targets/TargetMemorySegmentDescriptor.hpp"
+#include "src/Targets/TargetPeripheralDescriptor.hpp"
+#include "src/Targets/TargetRegisterGroupDescriptor.hpp"
+
+namespace DebugServer::Gdb::RiscVGdb
+{
+    class RiscVGdbTargetDescriptor: public DebugServer::Gdb::TargetDescriptor
+    {
+    public:
+        const Targets::TargetAddressSpaceDescriptor& systemAddressSpaceDescriptor;
+        const Targets::TargetAddressSpaceDescriptor& cpuAddressSpaceDescriptor;
+
+        const Targets::TargetMemorySegmentDescriptor& programMemorySegmentDescriptor;
+        const Targets::TargetMemorySegmentDescriptor& gpRegistersMemorySegmentDescriptor;
+
+        const Targets::TargetPeripheralDescriptor& cpuGpPeripheralDescriptor;
+        const Targets::TargetRegisterGroupDescriptor& cpuGpRegisterGroupDescriptor;
+
+        const GdbRegisterId programCounterGdbRegisterId;
+
+        explicit RiscVGdbTargetDescriptor(const Targets::TargetDescriptor& targetDescriptor);
+    };
+}

src/Targets/RiscV/Wch/WchRiscV.cpp

@@ -85,6 +85,20 @@ namespace Targets::RiscV::Wch
         sysAddressSpaceDescriptor.getMemorySegmentDescriptor("internal_program_memory").inspectionEnabled = true;
         sysAddressSpaceDescriptor.getMemorySegmentDescriptor("internal_ram").inspectionEnabled = true;
 
+        /*
+         * WCH targets typically possess a memory segment that is mapped to program memory. We cannot write to this
+         * segment directly, which is why it's described as read-only in Bloom's TDFs. However, we enable writing to
+         * the segment by forwarding any write operations to the appropriate (aliased) segment.
+         *
+         * For this reason, we adjust the access member on the memory segment descriptor so that other components
+         * within Bloom will see the segment as writeable.
+         *
+         * See the overridden WchRiscV::writeMemory() member function below, for more.
+         */
+        sysAddressSpaceDescriptor.getMemorySegmentDescriptor(
+            this->mappedProgramMemorySegmentDescriptor.key
+        ).programmingModeAccess.writeable = true;
+
         return descriptor;
     }
 
@@ -95,12 +109,16 @@ namespace Targets::RiscV::Wch
         const TargetMemoryBuffer& buffer
     ) {
         /*
-         * WCH targets have a memory segment that maps to either the program memory segment or the boot program
+         * WCH targets have an alias segment that maps to either the program memory segment or the boot program
          * memory segment.
          *
-         * Reading directly from the mapped memory segment is fine, but we cannot write to it - the operation just
-         * fails silently. We handle this by altering the write operation so that we write to the appropriate,
-         * non-mapped segment.
+         * Reading directly from this memory segment is fine, but we cannot write to it - the operation just fails
+         * silently. We handle this by forwarding any write operations on that segment to the appropriate (aliased)
+         * segment.
+         *
+         * @TODO: Currently, this just assumes that the alias segment always maps to the program memory segment, but I
+         *        believe it may map to the boot program memory segment in some cases. This needs to be revisited
+         *        before v1.1.0.
          */
         if (memorySegmentDescriptor == this->mappedProgramMemorySegmentDescriptor) {
             const auto newAddress = startAddress - this->mappedProgramMemorySegmentDescriptor.addressRange.startAddress