Adding boot/user mode switching functionality for WCH RISC-V targets

src/Targets/DynamicRegisterValue.cpp

@@ -69,14 +69,6 @@ namespace Targets
         return this->bitField(this->registerDescriptor.getBitFieldDescriptor(bitFieldKey));
     }
 
-    bool DynamicRegisterValue::bitFieldFlag(const TargetBitFieldDescriptor& bitFieldDescriptor) const {
-        return static_cast<bool>(this->bitField(bitFieldDescriptor));
-    }
-
-    bool DynamicRegisterValue::bitFieldFlag(const std::string& bitFieldKey) const {
-        return this->bitFieldFlag(this->registerDescriptor.getBitFieldDescriptor(bitFieldKey));
-    }
-
     TargetMemoryBuffer DynamicRegisterValue::data() const {
         auto output = TargetMemoryBuffer(this->registerDescriptor.size, 0x00);
 

src/Targets/DynamicRegisterValue.hpp

@@ -24,8 +24,11 @@ namespace Targets
 
         [[nodiscard]] std::uint64_t bitField(const TargetBitFieldDescriptor& bitFieldDescriptor) const;
         [[nodiscard]] std::uint64_t bitField(const std::string& bitFieldKey) const;
-        [[nodiscard]] bool bitFieldFlag(const TargetBitFieldDescriptor& bitFieldDescriptor) const;
+
-        [[nodiscard]] bool bitFieldFlag(const std::string& bitFieldKey) const;
+        template <typename ReturnType>
+        [[nodiscard]] ReturnType bitFieldAs(const TargetBitFieldDescriptor& bitFieldDescriptor) const {
+            return static_cast<ReturnType>(this->bitField(bitFieldDescriptor));
+        }
 
         [[nodiscard]] TargetMemoryBuffer data() const;
     };

src/Targets/RiscV/Wch/WchRiscV.cpp

@@ -3,6 +3,9 @@
 #include <utility>
 #include <cassert>
 
+
+#include "src/Targets/DynamicRegisterValue.hpp"
+
 #include "src/Exceptions/InvalidConfig.hpp"
 #include "src/Exceptions/Exception.hpp"
 
@@ -28,6 +31,12 @@ namespace Targets::RiscV::Wch
                 ? this->bootProgramSegmentDescriptor
                 : this->mainProgramSegmentDescriptor
         )
+        , flashPeripheralDescriptor(this->targetDescriptionFile.getTargetPeripheralDescriptor("flash"))
+        , flashKeyRegisterDescriptor(this->flashPeripheralDescriptor.getRegisterDescriptor("flash", "keyr"))
+        , flashBootKeyRegisterDescriptor(this->flashPeripheralDescriptor.getRegisterDescriptor("flash", "boot_modekeyr"))
+        , flashStatusRegisterDescriptor(this->flashPeripheralDescriptor.getRegisterDescriptor("flash", "statr"))
+        , flashStatusBootLockFieldDescriptor(this->flashStatusRegisterDescriptor.getBitFieldDescriptor("boot_lock"))
+        , flashStatusBootModeFieldDescriptor(this->flashStatusRegisterDescriptor.getBitFieldDescriptor("boot_mode"))
     {
         Logger::info(
             "Selected program memory segment: \"" + this->selectedProgramSegmentDescriptor.name + "\" (\""
@@ -390,4 +399,48 @@ namespace Targets::RiscV::Wch
 
         return transformedAddress;
     }
+
+    void WchRiscV::unlockFlash() {
+        // TODO: Move these key values to a TDF property. After v2.0.0
+        this->writeRegister(this->flashKeyRegisterDescriptor, 0x45670123);
+        this->writeRegister(this->flashKeyRegisterDescriptor, 0xCDEF89AB);
+    }
+
+    void WchRiscV::unlockBootModeBitField() {
+        // TODO: Move these key values to a TDF property. After v2.0.0
+        this->writeRegister(this->flashBootKeyRegisterDescriptor, 0x45670123);
+        this->writeRegister(this->flashBootKeyRegisterDescriptor, 0xCDEF89AB);
+    }
+
+    void WchRiscV::enableBootMode() {
+        this->unlockFlash();
+        this->unlockBootModeBitField();
+
+        auto statusRegister = this->readRegisterDynamicValue(this->flashStatusRegisterDescriptor);
+
+        if (statusRegister.bitFieldAs<bool>(this->flashStatusBootLockFieldDescriptor)) {
+            throw Exceptions::Exception{"Failed to unlock boot mode field"};
+        }
+
+        statusRegister.setBitField(this->flashStatusBootModeFieldDescriptor, true);
+        this->writeRegister(this->flashStatusRegisterDescriptor, statusRegister.data());
+
+        this->reset();
+    }
+
+    void WchRiscV::enableUserMode() {
+        this->unlockFlash();
+        this->unlockBootModeBitField();
+
+        auto statusRegister = this->readRegisterDynamicValue(this->flashStatusRegisterDescriptor);
+
+        if (statusRegister.bitFieldAs<bool>(this->flashStatusBootLockFieldDescriptor)) {
+            throw Exceptions::Exception{"Failed to unlock boot mode field"};
+        }
+
+        statusRegister.setBitField(this->flashStatusBootModeFieldDescriptor, false);
+        this->writeRegister(this->flashStatusRegisterDescriptor, statusRegister.data());
+
+        this->reset();
+    }
 }

src/Targets/RiscV/Wch/WchRiscV.hpp

@@ -73,10 +73,23 @@ namespace Targets::RiscV::Wch
          */
         const TargetMemorySegmentDescriptor& selectedProgramSegmentDescriptor;
 
+        const TargetPeripheralDescriptor flashPeripheralDescriptor;
+        const TargetRegisterDescriptor& flashKeyRegisterDescriptor;
+        const TargetRegisterDescriptor& flashBootKeyRegisterDescriptor;
+        const TargetRegisterDescriptor& flashStatusRegisterDescriptor;
+
+        const TargetBitFieldDescriptor& flashStatusBootLockFieldDescriptor;
+        const TargetBitFieldDescriptor& flashStatusBootModeFieldDescriptor;
+
         const TargetMemorySegmentDescriptor& resolveAliasedMemorySegment();
         TargetMemoryAddress transformMappedAddress(
             TargetMemoryAddress address,
             const TargetMemorySegmentDescriptor& segmentDescriptor
         );
+
+        void unlockFlash();
+        void unlockBootModeBitField();
+        void enableBootMode();
+        void enableUserMode();
     };
 }