Openknx version support (#190)

* Feature: Allow additional version check on startup
- added versionCheckCallback
- added apiVersion to DeviceObject
- added new versionCheck to memory,cpp

* updated source code formatting

* changes for PR
- (old) version is again part of version check
- naming conventions

* forgotten parameter in callback

* correct wrong buffer initialization

* version <-> apiVersion swapped

Co-authored-by: Waldemar Porscha <waldemar.porscha@sap.com>

src/knx/bau_systemB.cpp

@@ -614,6 +614,16 @@ Memory& BauSystemB::memory()
     return _memory;
 }
 
+void BauSystemB::versionCheckCallback(VersionCheckCallback func)
+{
+    _memory.versionCheckCallback(func);
+}
+
+VersionCheckCallback BauSystemB::versionCheckCallback()
+{
+    return _memory.versionCheckCallback();
+}
+
 void BauSystemB::beforeRestartCallback(BeforeRestartCallback func)
 {
     _beforeRestart = func;

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 versionCheckCallback(VersionCheckCallback func);
+    VersionCheckCallback versionCheckCallback();
     void beforeRestartCallback(BeforeRestartCallback func);
     BeforeRestartCallback beforeRestartCallback();
 

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

@@ -29,38 +29,68 @@ void Memory::readMemory()
 
     _freeList = new MemoryBlock(flashStart + metadataBlockSize, flashSize - metadataBlockSize);
 
+    uint16_t apiVersion = 0;
+    const uint8_t* buffer = popWord(apiVersion, flashStart);
+
     uint16_t manufacturerId = 0;
-    const uint8_t* buffer = popWord(manufacturerId, flashStart);
+    buffer = popWord(manufacturerId, buffer);
 
     uint8_t hardwareType[LEN_HARDWARE_TYPE] = {0};
     buffer = popByteArray(hardwareType, LEN_HARDWARE_TYPE, buffer);
 
     uint16_t version = 0;
     buffer = popWord(version, buffer);
-    
-    
-    
-    if (_deviceObject.manufacturerId() != manufacturerId
-       || _deviceObject.version() != version
-       || memcmp(_deviceObject.hardwareType(), hardwareType, LEN_HARDWARE_TYPE) != 0)
+
+    VersionCheckResult versionCheck = FlashAllInvalid;
+
+    // first check correct format of deviceObject-API
+    if (_deviceObject.apiVersion == apiVersion) 
     {
-        println("saved memory doesn't match manufacturerId, version or hardwaretype");
-        print("manufacturerId: ");
-        print(manufacturerId, HEX);
-        print(" ");
-        println(_deviceObject.manufacturerId(), HEX);
-        print("version: ");
-        print(version, HEX);
-        print(" ");
-        println(_deviceObject.version(), HEX);
-        print("hardwareType: ");
-        printHex("", hardwareType, LEN_HARDWARE_TYPE);
-        print(" ");
-        printHex("", _deviceObject.hardwareType(), LEN_HARDWARE_TYPE);
+        if (_versionCheckCallback != 0) {
+            versionCheck = _versionCheckCallback(manufacturerId, hardwareType, version);
+            // callback should provide infomation about version check failure reasons
+        }
+        else if (_deviceObject.manufacturerId() == manufacturerId &&
+                 memcmp(_deviceObject.hardwareType(), hardwareType, LEN_HARDWARE_TYPE) == 0) 
+        {
+            if (_deviceObject.version() == version) {
+                versionCheck = FlashValid;
+            } 
+            else
+            {
+                versionCheck = FlashTablesInvalid;
+            }
+        } 
+        else 
+        {
+            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(apiVersion, 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 +100,11 @@ 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++)
@@ -103,6 +138,7 @@ void Memory::writeMemory()
     uint32_t flashPos = 0;
     uint8_t* bufferPos = buffer;
 
+    bufferPos = pushWord(_deviceObject.apiVersion, bufferPos);
     bufferPos = pushWord(_deviceObject.manufacturerId(), bufferPos);
     bufferPos = pushByteArray(_deviceObject.hardwareType(), LEN_HARDWARE_TYPE, bufferPos);
     bufferPos = pushWord(_deviceObject.version(), bufferPos);
@@ -451,3 +487,13 @@ void Memory::addNewUsedBlock(uint8_t* address, size_t size)
     MemoryBlock* newUsedBlock = new MemoryBlock(address, size);
     addToUsedList(newUsedBlock);
 }
+
+void Memory::versionCheckCallback(VersionCheckCallback func)
+{
+    _versionCheckCallback = func;
+}
+
+VersionCheckCallback Memory::versionCheckCallback()
+{
+    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, uint16_t version);
+
 class Memory
 {
 public:
@@ -41,6 +50,9 @@ public:
     uint8_t* toAbsolute(uint32_t relativeAddress);
     uint32_t toRelative(uint8_t* absoluteAddress);
 
+    void versionCheckCallback(VersionCheckCallback func);
+    VersionCheckCallback versionCheckCallback();
+
   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};
@@ -64,5 +77,5 @@ public:
     uint8_t _tableObjCount = 0;
     MemoryBlock* _freeList = nullptr;
     MemoryBlock* _usedList = nullptr;
-    uint16_t _metadataSize = 4 + LEN_HARDWARE_TYPE; // accounting for 2x pushWord and pushByteArray of length LEN_HARDWARE_TYPE
+    uint16_t _metadataSize = 6 + LEN_HARDWARE_TYPE; // accounting for 3x pushWord and pushByteArray of length LEN_HARDWARE_TYPE
 };