add support for external flash system by using callbacks

src/knx/platform.cpp

@@ -140,6 +140,10 @@ uint8_t* Platform::getNonVolatileMemoryStart()
 {
     if(_memoryType == Flash)
         return userFlashStart();
+#ifdef KNX_FLASH_CALLBACK
+    else if(_memoryType == Callback)
+        return _callbackFlashRead();
+#endif
     else
         return getEepromBuffer(KNX_FLASH_SIZE);
 }
@@ -148,6 +152,10 @@ size_t Platform::getNonVolatileMemorySize()
 {
     if(_memoryType == Flash)
         return userFlashSizeEraseBlocks() * flashEraseBlockSize() * flashPageSize();
+#ifdef KNX_FLASH_CALLBACK
+    else if(_memoryType == Callback)
+        return _callbackFlashSize();
+#endif
     else
         return KNX_FLASH_SIZE;
 }
@@ -165,6 +173,10 @@ void Platform::commitNonVolatileMemory()
             _bufferedEraseblockNumber = -1;  // does that make sense?
         }
     }
+#ifdef KNX_FLASH_CALLBACK
+    else if(_memoryType == Callback)
+        return _callbackFlashCommit();
+#endif
     else
     {
         commitToEeprom();
@@ -194,6 +206,10 @@ uint32_t Platform::writeNonVolatileMemory(uint32_t relativeAddress, uint8_t* buf
         }
         return relativeAddress;
     }
+#ifdef KNX_FLASH_CALLBACK
+    else if(_memoryType == Callback)
+        return _callbackFlashWrite(relativeAddress, buffer, size);
+#endif
     else
     {
         memcpy(getEepromBuffer(KNX_FLASH_SIZE)+relativeAddress, buffer, size);
@@ -283,3 +299,38 @@ void Platform::bufferEraseBlock(int32_t eraseBlockNumber)
     _bufferedEraseblockNumber = eraseBlockNumber;
     _bufferedEraseblockDirty = false;
 }
+
+
+#ifdef KNX_FLASH_CALLBACK
+void Platform::registerFlashCallbacks(
+    FlashCallbackSize callbackFlashSize,
+    FlashCallbackRead callbackFlashRead,
+    FlashCallbackWrite callbackFlashWrite,
+    FlashCallbackCommit callbackFlashCommit)
+    {
+        println("Set Callback");
+        _memoryType = Callback;
+        _callbackFlashSize = callbackFlashSize;
+        _callbackFlashRead = callbackFlashRead;
+        _callbackFlashWrite = callbackFlashWrite;
+        _callbackFlashCommit = callbackFlashCommit;
+        _callbackFlashSize();
+    }
+
+FlashCallbackSize Platform::callbackFlashSize()
+{
+   return _callbackFlashSize;
+}
+FlashCallbackRead Platform::callbackFlashRead()
+{
+   return _callbackFlashRead;
+}
+FlashCallbackWrite Platform::callbackFlashWrite()
+{
+   return _callbackFlashWrite;
+}
+FlashCallbackCommit Platform::callbackFlashCommit()
+{
+   return _callbackFlashCommit;
+}
+#endif

src/knx/platform.h

@@ -4,15 +4,28 @@
 #include <stddef.h>
 #include "save_restore.h"
 
+#ifndef KNX_FLASH_CALLBACK
 #ifndef KNX_FLASH_SIZE
 #define KNX_FLASH_SIZE 1024
 #pragma warning "KNX_FLASH_SIZE not defined, using 1024"
 #endif
+#endif
+
+#ifdef KNX_FLASH_CALLBACK
+#ifndef KNX_FLASH_SIZE
+#define KNX_FLASH_SIZE 0
+#endif
+typedef uint32_t (*FlashCallbackSize)();
+typedef uint8_t* (*FlashCallbackRead)();
+typedef uint32_t (*FlashCallbackWrite)(uint32_t relativeAddress, uint8_t* buffer, size_t len);
+typedef void (*FlashCallbackCommit)();
+#endif
 
 enum NvMemoryType
 {
     Eeprom,
-    Flash
+    Flash,
+    Callback
 };
 
 class Platform
@@ -75,13 +88,26 @@ class Platform
     NvMemoryType NonVolatileMemoryType();
     void NonVolatileMemoryType(NvMemoryType type);
 
-  // --- Overwrite these methods in the device-plattform to use flash memory handling by the knx stack ---
+    // --- Overwrite these methods in the device-plattform to use flash memory handling by the knx stack ---
-  // --- also set _memoryType = Flash in the device-plattform's contructor
+    // --- also set _memoryType = Flash in the device-plattform's contructor
-  // --- optional: overwrite writeBufferedEraseBlock() in the device-plattform to reduce overhead when flashing multiple pages
+    // --- optional: overwrite writeBufferedEraseBlock() in the device-plattform to reduce overhead when flashing multiple pages
 
     // size of one flash page in bytes
     virtual size_t flashPageSize();
     
+#ifdef KNX_FLASH_CALLBACK
+    void registerFlashCallbacks(
+        FlashCallbackSize callbackFlashSize,
+        FlashCallbackRead callbackFlashRead,
+        FlashCallbackWrite callbackFlashWrite,
+        FlashCallbackCommit callbackFlashCommit);
+
+    FlashCallbackSize callbackFlashSize();
+    FlashCallbackRead callbackFlashRead();
+    FlashCallbackWrite callbackFlashWrite();
+    FlashCallbackCommit callbackFlashCommit();
+#endif
+
   protected:
     // size of one EraseBlock in pages
     virtual size_t flashEraseBlockSize();
@@ -95,8 +121,7 @@ class Platform
     virtual void flashWritePage(uint16_t pageNumber, uint8_t* data);
 
 
-  // -------------------------------------------------------------------------------------------------------
+    // -------------------------------------------------------------------------------------------------------
-
 
     NvMemoryType _memoryType = Eeprom;
 
@@ -113,4 +138,11 @@ class Platform
     uint8_t* _eraseblockBuffer = nullptr;
     int32_t _bufferedEraseblockNumber = -1;
     bool _bufferedEraseblockDirty = false;
+
+#ifdef KNX_FLASH_CALLBACK
+    FlashCallbackSize _callbackFlashSize = nullptr;
+    FlashCallbackRead _callbackFlashRead = nullptr;
+    FlashCallbackWrite _callbackFlashWrite = nullptr;
+    FlashCallbackCommit _callbackFlashCommit = nullptr;
+#endif
 };