From 38260dc358aa3d635f8faa9933bd32031a45b543 Mon Sep 17 00:00:00 2001
From: Nav <nav@navnav.me>
Date: Fri, 4 Mar 2022 23:43:26 +0000
Subject: [PATCH] DWEN & SPIEN fuse bit descriptor extraction from AVR8 TDFs

---
 .../TargetDescriptionFile.cpp                 | 47 +++++++++++++++++++
 .../TargetDescriptionFile.hpp                 | 21 +++++++++
 2 files changed, 68 insertions(+)

diff --git a/src/Targets/Microchip/AVR/AVR8/TargetDescription/TargetDescriptionFile.cpp b/src/Targets/Microchip/AVR/AVR8/TargetDescription/TargetDescriptionFile.cpp
index f12bdaff..19a9208a 100644
--- a/src/Targets/Microchip/AVR/AVR8/TargetDescription/TargetDescriptionFile.cpp
+++ b/src/Targets/Microchip/AVR/AVR8/TargetDescription/TargetDescriptionFile.cpp
@@ -376,6 +376,14 @@ namespace Bloom::Targets::Microchip::Avr::Avr8Bit::TargetDescription
         return output;
     }
 
+    std::optional<FuseBitDescriptor> TargetDescriptionFile::getDwenFuseBitDescriptor() const {
+        return this->getFuseBitDescriptorByName("dwen");
+    }
+
+    std::optional<FuseBitDescriptor> TargetDescriptionFile::getSpienFuseBitDescriptor() const {
+        return this->getFuseBitDescriptorByName("spien");
+    }
+
     void TargetDescriptionFile::loadDebugPhysicalInterfaces() {
         auto interfaceNamesToInterfaces = std::map<std::string, PhysicalInterface>({
            {"updi", PhysicalInterface::UPDI},
@@ -619,6 +627,45 @@ namespace Bloom::Targets::Microchip::Avr::Avr8Bit::TargetDescription
         }
     }
 
+    std::optional<FuseBitDescriptor> TargetDescriptionFile::getFuseBitDescriptorByName(
+        const std::string& fuseBitName
+    ) const {
+        if (!this->modulesMappedByName.contains("fuse")) {
+            return std::nullopt;
+        }
+
+        const auto& fuseModule = this->modulesMappedByName.at("fuse");
+
+        if (!fuseModule.registerGroupsMappedByName.contains("fuse")) {
+            return std::nullopt;
+        }
+
+        const auto& fuseRegisterGroup = fuseModule.registerGroupsMappedByName.at("fuse");
+
+        static const auto fuseTypesByName = std::map<std::string, FuseType>(
+            {
+                {"low", FuseType::LOW},
+                {"high", FuseType::HIGH},
+                {"extended", FuseType::EXTENDED},
+            }
+        );
+
+        for (const auto&[fuseTypeName, fuse] : fuseRegisterGroup.registersMappedByName) {
+            if (!fuseTypesByName.contains(fuseTypeName)) {
+                // Unknown fuse type name
+                continue;
+            }
+
+            if (fuse.bitFieldsMappedByName.contains(fuseBitName)) {
+                return FuseBitDescriptor(
+                    fuseTypesByName.at(fuseTypeName),
+                    fuse.bitFieldsMappedByName.at(fuseBitName).mask
+                );
+            }
+        }
+
+        return std::nullopt;
+    }
     std::optional<MemorySegment> TargetDescriptionFile::getFlashMemorySegment() const {
         auto& addressMapping = this->addressSpacesMappedById;
         auto programAddressSpaceIt = addressMapping.find("prog");
diff --git a/src/Targets/Microchip/AVR/AVR8/TargetDescription/TargetDescriptionFile.hpp b/src/Targets/Microchip/AVR/AVR8/TargetDescription/TargetDescriptionFile.hpp
index c65098ae..49268144 100644
--- a/src/Targets/Microchip/AVR/AVR8/TargetDescription/TargetDescriptionFile.hpp
+++ b/src/Targets/Microchip/AVR/AVR8/TargetDescription/TargetDescriptionFile.hpp
@@ -9,6 +9,7 @@
 
 #include "src/Targets/Microchip/AVR/TargetSignature.hpp"
 #include "src/Targets/Microchip/AVR/IspParameters.hpp"
+#include "src/Targets/Microchip/AVR/Fuse.hpp"
 
 #include "src/Targets/Microchip/AVR/AVR8/Family.hpp"
 #include "src/Targets/Microchip/AVR/AVR8/PhysicalInterface.hpp"
@@ -82,6 +83,24 @@ namespace Bloom::Targets::Microchip::Avr::Avr8Bit::TargetDescription
          */
         [[nodiscard]] IspParameters getIspParameters() const;
 
+        /**
+         * Constructs a FuseBitDescriptor for the debugWire enable (DWEN) fuse bit, with information extracted from
+         * the TDF.
+         *
+         * @return
+         *  std::nullopt if the DWEN bit field could not be found in the TDF.
+         */
+        [[nodiscard]] std::optional<FuseBitDescriptor> getDwenFuseBitDescriptor() const;
+
+        /**
+         * Constructs a FuseBitDescriptor for the SPI enable (SPIEN) fuse bit, with information extracted from
+         * the TDF.
+         *
+         * @return
+         *  std::nullopt if the SPIEN bit field could not be found in the TDF.
+         */
+        [[nodiscard]] std::optional<FuseBitDescriptor> getSpienFuseBitDescriptor() const;
+
         /**
          * Returns a set of all supported physical interfaces for debugging.
          *
@@ -169,6 +188,8 @@ namespace Bloom::Targets::Microchip::Avr::Avr8Bit::TargetDescription
          */
         void loadTargetRegisterDescriptors();
 
+        [[nodiscard]] std::optional<FuseBitDescriptor> getFuseBitDescriptorByName(const std::string& fuseBitName) const;
+
         [[nodiscard]] std::optional<Targets::TargetDescription::MemorySegment> getFlashMemorySegment() const;
         [[nodiscard]] std::optional<Targets::TargetDescription::MemorySegment> getRamMemorySegment() const;
         [[nodiscard]] std::optional<Targets::TargetDescription::MemorySegment> getIoMemorySegment() const;