From 71150163c44f62f1e0f0881344a43100473c4724 Mon Sep 17 00:00:00 2001
From: Nav <nav@navnav.me>
Date: Sat, 23 Nov 2024 23:12:38 +0000
Subject: [PATCH] Added abstract data register count check when identifying
 supported memory access strategies

---
 .../AbstractControlStatusRegister.hpp         |  6 +--
 .../RiscVDebugSpec/DebugModuleDescriptor.hpp  |  1 +
 .../RiscVDebugSpec/DebugTranslator.cpp        | 44 ++++++++++---------
 3 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugModule/Registers/AbstractControlStatusRegister.hpp b/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugModule/Registers/AbstractControlStatusRegister.hpp
index bb845be0..b063cdbe 100644
--- a/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugModule/Registers/AbstractControlStatusRegister.hpp
+++ b/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugModule/Registers/AbstractControlStatusRegister.hpp
@@ -8,7 +8,7 @@ namespace DebugToolDrivers::Protocols::RiscVDebugSpec::DebugModule::Registers
 {
     struct AbstractControlStatusRegister
     {
-        std::uint8_t dataCount = 0;
+        std::uint8_t dataRegisterCount = 0;
         AbstractCommandError commandError = AbstractCommandError::NONE;
         bool relaxedPrivilege = false;
         bool busy = false;
@@ -16,7 +16,7 @@ namespace DebugToolDrivers::Protocols::RiscVDebugSpec::DebugModule::Registers
 
         static constexpr AbstractControlStatusRegister fromValue(RegisterValue value) {
             return {
-                .dataCount = static_cast<std::uint8_t>(value & 0x0F),
+                .dataRegisterCount = static_cast<std::uint8_t>(value & 0x0F),
                 .commandError = static_cast<AbstractCommandError>((value >> 8) & 0x07),
                 .relaxedPrivilege = static_cast<bool>(value & (0x01 << 11)),
                 .busy = static_cast<bool>(value & (0x01 << 12)),
@@ -26,7 +26,7 @@ namespace DebugToolDrivers::Protocols::RiscVDebugSpec::DebugModule::Registers
 
         [[nodiscard]] constexpr RegisterValue value() const {
             return RegisterValue{0}
-                | static_cast<RegisterValue>(this->dataCount & 0x0F)
+                | static_cast<RegisterValue>(this->dataRegisterCount & 0x0F)
                 | static_cast<RegisterValue>(this->commandError) << 8
                 | static_cast<RegisterValue>(this->relaxedPrivilege) << 11
                 | static_cast<RegisterValue>(this->busy) << 12
diff --git a/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugModuleDescriptor.hpp b/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugModuleDescriptor.hpp
index 416f5629..9b98d1db 100644
--- a/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugModuleDescriptor.hpp
+++ b/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugModuleDescriptor.hpp
@@ -19,6 +19,7 @@ namespace DebugToolDrivers::Protocols::RiscVDebugSpec
         std::vector<DebugModule::HartIndex> hartIndices;
 
         std::unordered_set<DebugModule::MemoryAccessStrategy> memoryAccessStrategies;
+        std::uint8_t abstractDataRegisterCount = 0;
         std::uint8_t programBufferSize = 0;
 
         std::unordered_map<TriggerModule::TriggerIndex, TriggerModule::TriggerDescriptor> triggerDescriptorsByIndex;
diff --git a/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugTranslator.cpp b/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugTranslator.cpp
index fa163403..77d736a8 100644
--- a/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugTranslator.cpp
+++ b/src/DebugToolDrivers/Protocols/RiscVDebugSpec/DebugTranslator.cpp
@@ -128,33 +128,37 @@ namespace DebugToolDrivers::Protocols::RiscVDebugSpec
         this->initDebugControlStatusRegister();
 
         const auto abstractControlStatusRegister = this->readDebugModuleAbstractControlStatusRegister();
+        this->debugModuleDescriptor.abstractDataRegisterCount = abstractControlStatusRegister.dataRegisterCount;
         this->debugModuleDescriptor.programBufferSize = abstractControlStatusRegister.programBufferSize;
 
+        Logger::debug("Data register count: " + std::to_string(this->debugModuleDescriptor.abstractDataRegisterCount));
         Logger::debug("Program buffer size: " + std::to_string(this->debugModuleDescriptor.programBufferSize));
 
-        if (this->debugModuleDescriptor.programBufferSize >= 3) {
-            this->debugModuleDescriptor.memoryAccessStrategies.insert(MemoryAccessStrategy::PROGRAM_BUFFER);
-        }
+        if (this->debugModuleDescriptor.abstractDataRegisterCount > 0) {
+            if (this->debugModuleDescriptor.programBufferSize >= 3) {
+                this->debugModuleDescriptor.memoryAccessStrategies.insert(MemoryAccessStrategy::PROGRAM_BUFFER);
+            }
 
-        /*
-         * Attempt to read a single word from the start of the system address space, via a memory access abstract
-         * command.
-         */
-        constexpr auto probingMemoryAccessCommand = AbstractCommandRegister{
-            .control = MemoryAccessControlField{
-                .postIncrement = true,
-                .size = MemoryAccessControlField::MemorySize::SIZE_32,
-            }.value(),
-            .commandType = AbstractCommandRegister::CommandType::MEMORY_ACCESS
-        };
+            /*
+             * Attempt to read a single word from the start of the system address space, via a memory access abstract
+             * command.
+             */
+            constexpr auto probingMemoryAccessCommand = AbstractCommandRegister{
+                .control = MemoryAccessControlField{
+                    .postIncrement = true,
+                    .size = MemoryAccessControlField::MemorySize::SIZE_32,
+                }.value(),
+                .commandType = AbstractCommandRegister::CommandType::MEMORY_ACCESS
+            };
 
-        this->dtmInterface.writeDebugModuleRegister(
-            RegisterAddress::ABSTRACT_DATA_1,
-            this->targetDescriptionFile.getSystemAddressSpace().startAddress
-        );
+            this->dtmInterface.writeDebugModuleRegister(
+                RegisterAddress::ABSTRACT_DATA_1,
+                this->targetDescriptionFile.getSystemAddressSpace().startAddress
+            );
 
-        if (this->tryExecuteAbstractCommand(probingMemoryAccessCommand) == AbstractCommandError::NONE) {
-            this->debugModuleDescriptor.memoryAccessStrategies.insert(MemoryAccessStrategy::ABSTRACT_COMMAND);
+            if (this->tryExecuteAbstractCommand(probingMemoryAccessCommand) == AbstractCommandError::NONE) {
+                this->debugModuleDescriptor.memoryAccessStrategies.insert(MemoryAccessStrategy::ABSTRACT_COMMAND);
+            }
         }
 
         if (this->debugModuleDescriptor.memoryAccessStrategies.empty()) {