Feature: Allow additional version check on startup

- added versionCheckCallback
- added apiVersion to DeviceObject
- added new versionCheck to memory,cpp

src/knx/bau_systemB.cpp

@@ -611,3 +611,13 @@ Memory& BauSystemB::memory()
 {
     return _memory;
 }
+
+void BauSystemB::addVersionCheckCallback(versionCheckCallback func)
+{
+    _memory.addVersionCheckCallback(func);
+}
+
+versionCheckCallback BauSystemB::getVersionCheckCallback()
+{
+    return _memory.getVersionCheckCallback();
+}

src/knx/bau_systemB.h

@@ -38,6 +38,8 @@ class BauSystemB : protected BusAccessUnit
     void propertyValueWrite(ObjectType objectType, uint8_t objectInstance, uint8_t propertyId,
                             uint8_t& numberOfElements, uint16_t startIndex,
                             uint8_t* data, uint32_t length) override;
+    void addVersionCheckCallback(versionCheckCallback func);
+    versionCheckCallback getVersionCheckCallback();
 
   protected:
     virtual ApplicationLayer& applicationLayer() = 0;

src/knx/device_object.h

@@ -7,6 +7,10 @@
 class DeviceObject: public InterfaceObject
 {
 public:
+  // increase this version anytime DeviceObject-API changes 
+  // the following value represents the serialized representation of DeviceObject.
+  const uint16_t apiVersion = 1;
+  
   DeviceObject();
   uint8_t* save(uint8_t* buffer) override;
   const uint8_t* restore(const uint8_t* buffer) override;

src/knx/memory.cpp

@@ -38,29 +38,50 @@ void Memory::readMemory()
     uint16_t version = 0;
     buffer = popWord(version, buffer);
 
+    VersionCheckResult versionCheck = FlashAllInvalid;
 
-    
+    // first check correct format of deviceObject-API
-    if (_deviceObject.manufacturerId() != manufacturerId
+    if (_deviceObject.apiVersion == version) 
-       || _deviceObject.version() != version
-       || memcmp(_deviceObject.hardwareType(), hardwareType, LEN_HARDWARE_TYPE) != 0)
     {
-        println("saved memory doesn't match manufacturerId, version or hardwaretype");
+        if (_versionCheckCallback != 0) {
-        print("manufacturerId: ");
+            versionCheck = _versionCheckCallback(manufacturerId, hardwareType);
-        print(manufacturerId, HEX);
+            // callback should provide infomation about version check failure reasons
-        print(" ");
+        }
-        println(_deviceObject.manufacturerId(), HEX);
+        else if (_deviceObject.manufacturerId() == manufacturerId &&
-        print("version: ");
+                 memcmp(_deviceObject.hardwareType(), hardwareType, LEN_HARDWARE_TYPE) == 0) 
-        print(version, HEX);
+        {
-        print(" ");
+            versionCheck = FlashValid;
-        println(_deviceObject.version(), HEX);
+        } 
-        print("hardwareType: ");
+        else 
-        printHex("", hardwareType, LEN_HARDWARE_TYPE);
+        {
-        print(" ");
+            println("manufacturerId or hardwareType are different");
+            print("expexted manufacturerId: ");
+            print(_deviceObject.manufacturerId(), HEX);
+            print(", stored manufacturerId: ");
+            println(manufacturerId, HEX);
+            print("expexted hardwareType: ");
             printHex("", _deviceObject.hardwareType(), LEN_HARDWARE_TYPE);
+            print(", stored hardwareType: ");
+            printHex("", hardwareType, LEN_HARDWARE_TYPE);
+            println("");
+        }
+    } 
+    else 
+    {
+        println("DataObject api changed, any data stored in flash is invalid.");
+        print("expexted DataObject api version: ");
+        print(_deviceObject.apiVersion, HEX);
+        print(", stored api version: ");
+        println(version, HEX);
+    }
+
+    if (versionCheck == FlashAllInvalid)
+    {
+        println("ETS has to reprogram PA and application!");
         return;
     }
 
-    println("manufacturerId, version and hardwareType matches");
+    println("restoring data from flash...");
     print("saverestores ");
     println(_saveCount);
     for (int i = 0; i < _saveCount; i++)
@@ -70,6 +91,11 @@ void Memory::readMemory()
         buffer = _saveRestores[i]->restore(buffer);
     }
     println("restored saveRestores");
+    if (versionCheck == FlashTablesInvalid) 
+    {
+        println("TableObjects are referring to an older firmware version and are not loaded");
+        return;
+    }
     print("tableObjs ");
     println(_tableObjCount);
     for (int i = 0; i < _tableObjCount; i++)
@@ -105,7 +131,7 @@ void Memory::writeMemory()
 
     bufferPos = pushWord(_deviceObject.manufacturerId(), bufferPos);
     bufferPos = pushByteArray(_deviceObject.hardwareType(), LEN_HARDWARE_TYPE, bufferPos);
-    bufferPos = pushWord(_deviceObject.version(), bufferPos);
+    bufferPos = pushWord(_deviceObject.apiVersion, bufferPos);
 
     flashPos = _platform.writeNonVolatileMemory(flashPos, buffer, bufferPos - buffer);
 
@@ -451,3 +477,13 @@ void Memory::addNewUsedBlock(uint8_t* address, size_t size)
     MemoryBlock* newUsedBlock = new MemoryBlock(address, size);
     addToUsedList(newUsedBlock);
 }
+
+void Memory::addVersionCheckCallback(versionCheckCallback func)
+{
+    _versionCheckCallback = func;
+}
+
+versionCheckCallback Memory::getVersionCheckCallback()
+{
+    return _versionCheckCallback;
+}

src/knx/memory.h

@@ -24,6 +24,15 @@ class MemoryBlock
     MemoryBlock* next = nullptr;
 };
 
+enum VersionCheckResult
+{
+    FlashAllInvalid = 0,   //!< All flash content is not valid for this firmware, we delete it
+    FlashTablesInvalid = 1,//!< All table objects are invalid for this firmware, device object and saveRestores are OK
+    FlashValid = 2         //!< Flash content is valid and will be used
+};
+
+typedef VersionCheckResult (*versionCheckCallback)(uint16_t manufacturerId, uint8_t* hardwareType);
+
 class Memory
 {
 public:
@@ -41,6 +50,9 @@ public:
     uint8_t* toAbsolute(uint32_t relativeAddress);
     uint32_t toRelative(uint8_t* absoluteAddress);
 
+    void addVersionCheckCallback(versionCheckCallback func);
+    versionCheckCallback getVersionCheckCallback();
+
   private:
     void removeFromFreeList(MemoryBlock* block);
     void addToUsedList(MemoryBlock* block);
@@ -56,6 +68,7 @@ public:
     uint8_t* eraseBlockEnd(uint32_t blockNum);
     void saveBufferdEraseBlock();
 
+    versionCheckCallback _versionCheckCallback = 0;
     Platform& _platform;
     DeviceObject& _deviceObject;
     SaveRestore* _saveRestores[MAXSAVE] = {0};