- Get rid of EEPROM emulation (#186)

- Use SAMD-Flash without copying parameters to RAM

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

src/samd_platform.cpp

@@ -4,17 +4,29 @@
 #include <knx/bits.h>
 
 #include <Arduino.h>
+#ifdef USE_SAMD_EEPROM_EMULATION
 #include <FlashAsEEPROM.h>
+#endif
+
+#if KNX_FLASH_SIZE % 1024
+#error "KNX_FLASH_SIZE must be multiple of 1024"
+#endif
 
 SamdPlatform::SamdPlatform()
 #ifndef KNX_NO_DEFAULT_UART
     : ArduinoPlatform(&Serial1)
 #endif
 {
+#ifndef USE_SAMD_EEPROM_EMULATION
+    init();
+#endif
 }
 
 SamdPlatform::SamdPlatform( HardwareSerial* s) : ArduinoPlatform(s)
 {
+#ifndef USE_SAMD_EEPROM_EMULATION
+    init();
+#endif
 }
 
 uint32_t SamdPlatform::uniqueSerialNumber()
@@ -43,6 +55,8 @@ void SamdPlatform::restart()
     NVIC_SystemReset();
 }
 
+#ifdef USE_SAMD_EEPROM_EMULATION
+#pragma warning "Using EEPROM Simulation"
 uint8_t* SamdPlatform::getEepromBuffer(uint16_t size)
 {
     //EEPROM.begin(size);
@@ -56,6 +70,156 @@ void SamdPlatform::commitToEeprom()
 {
     EEPROM.commit();
 }
+#else
+
+extern uint32_t __etext;
+extern uint32_t __data_start__;
+extern uint32_t __data_end__;
+
+static const uint32_t pageSizes[] = {8, 16, 32, 64, 128, 256, 512, 1024};
+
+void SamdPlatform::init()
+{
+    _memoryType = Flash;
+    _pageSize = pageSizes[NVMCTRL->PARAM.bit.PSZ];
+    _pageCnt = NVMCTRL->PARAM.bit.NVMP;
+    _rowSize = PAGES_PER_ROW * _pageSize;
+
+    // find end of program flash and set limit to next row
+    uint32_t endEddr = (uint32_t)(&__etext + (&__data_end__ - &__data_start__)); // text + data MemoryBlock
+    _MemoryStart = getRowAddr(_pageSize * _pageCnt - KNX_FLASH_SIZE - 1);        // 23295
+    _MemoryEnd = getRowAddr(_pageSize * _pageCnt - 1);
+    // chosen flash size is not available anymore
+    if (_MemoryStart < endEddr) {
+        println("KNX_FLASH_SIZE is not available (possible too much flash use by firmware)");
+        fatalError();
+    }
+}
+
+size_t SamdPlatform::flashEraseBlockSize()
+{
+    return PAGES_PER_ROW;
+}
+
+size_t SamdPlatform::flashPageSize()
+{
+    return _pageSize;
+}
+
+uint8_t* SamdPlatform::userFlashStart()
+{
+    return (uint8_t*)_MemoryStart;
+}
+
+size_t SamdPlatform::userFlashSizeEraseBlocks()
+{
+    if (KNX_FLASH_SIZE <= 0)
+        return 0;
+    else
+        return ((KNX_FLASH_SIZE - 1) / (flashPageSize() * flashEraseBlockSize())) + 1;
+}
+
+void SamdPlatform::flashErase(uint16_t eraseBlockNum)
+{
+    noInterrupts();
+
+    eraseRow((void *)(_MemoryStart + eraseBlockNum * _rowSize));
+    // flash_range_erase(KNX_FLASH_OFFSET + eraseBlockNum * flashPageSize() * flashEraseBlockSize(), flashPageSize() * flashEraseBlockSize());
+
+    interrupts();
+}
+
+void SamdPlatform::flashWritePage(uint16_t pageNumber, uint8_t* data)
+{
+    noInterrupts();
+
+    write((void *)(_MemoryStart + pageNumber * _pageSize), data, _pageSize);
+    // flash_range_program(KNX_FLASH_OFFSET + pageNumber * flashPageSize(), data, flashPageSize());
+
+    interrupts();
+}
+
+void SamdPlatform::writeBufferedEraseBlock()
+{
+    if (_bufferedEraseblockNumber > -1 && _bufferedEraseblockDirty)
+    {
+        noInterrupts();
+
+        eraseRow((void *)(_MemoryStart + _bufferedEraseblockNumber * _rowSize));
+        write((void *)(_MemoryStart + _bufferedEraseblockNumber * _rowSize), _eraseblockBuffer, _rowSize);
+        // flash_range_erase(KNX_FLASH_OFFSET + _bufferedEraseblockNumber * flashPageSize() * flashEraseBlockSize(), flashPageSize() * flashEraseBlockSize());
+        // flash_range_program(KNX_FLASH_OFFSET + _bufferedEraseblockNumber * flashPageSize() * flashEraseBlockSize(), _eraseblockBuffer, flashPageSize() * flashEraseBlockSize());
+
+        interrupts();
+
+        _bufferedEraseblockDirty = false;
+    }
+}
+
+uint32_t SamdPlatform::getRowAddr(uint32_t flasAddr)
+{
+    return flasAddr & ~(_rowSize - 1);
+}
+
+void SamdPlatform::write(const volatile void *flash_ptr, const void *data, uint32_t size)
+{
+    // Calculate data boundaries
+    size = (size + 3) / 4;
+    volatile uint32_t *src_addr = (volatile uint32_t *)data;
+    volatile uint32_t *dst_addr = (volatile uint32_t *)flash_ptr;
+    // volatile uint32_t *dst_addr = (volatile uint32_t *)flash_ptr;
+    // const uint8_t *src_addr = (uint8_t *)data;
+
+    // Disable automatic page write
+    NVMCTRL->CTRLB.bit.MANW = 1;
+
+    // Do writes in pages
+    while (size)
+    {
+        // Execute "PBC" Page Buffer Clear
+        NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_PBC;
+        while (NVMCTRL->INTFLAG.bit.READY == 0)
+        {
+        }
+
+        // Fill page buffer
+        uint32_t i;
+        for (i = 0; i < (_pageSize / 4) && size; i++)
+        {
+            *dst_addr = *src_addr;
+            src_addr++;
+            dst_addr++;
+            size--;
+        }
+
+        // Execute "WP" Write Page
+        NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_WP;
+        while (NVMCTRL->INTFLAG.bit.READY == 0)
+        {
+        }
+    }
+}
+
+void SamdPlatform::erase(const volatile void *flash_ptr, uint32_t size)
+{
+    const uint8_t *ptr = (const uint8_t *)flash_ptr;
+    while (size > _rowSize)
+    {
+        eraseRow(ptr);
+        ptr += _rowSize;
+        size -= _rowSize;
+    }
+    eraseRow(ptr);
+}
+
+void SamdPlatform::eraseRow(const volatile void *flash_ptr)
+{
+    NVMCTRL->ADDR.reg = ((uint32_t)flash_ptr) / 2;
+    NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_ER;
+    while (!NVMCTRL->INTFLAG.bit.READY)
+    {
+    }
+}
+
+#endif
 #endif
-
-

src/samd_platform.h

@@ -4,6 +4,8 @@
 
 #ifdef ARDUINO_ARCH_SAMD
 
+#define PAGES_PER_ROW 4
+
 class SamdPlatform : public ArduinoPlatform
 {
 public:
@@ -14,8 +16,40 @@ public:
     uint32_t uniqueSerialNumber() override;
 
     void restart();
+#ifdef USE_SAMD_EEPROM_EMULATION
     uint8_t* getEepromBuffer(uint16_t size);
     void commitToEeprom();
+#else
+    // size of one EraseBlock in pages
+    virtual size_t flashEraseBlockSize();
+    // size of one flash page in bytes
+    virtual size_t flashPageSize();
+    // start of user flash aligned to start of an erase block
+    virtual uint8_t* userFlashStart();
+    // size of the user flash in EraseBlocks
+    virtual size_t userFlashSizeEraseBlocks();
+    // relativ to userFlashStart
+    virtual void flashErase(uint16_t eraseBlockNum);
+    // write a single page to flash (pageNumber relative to userFashStart
+    virtual void flashWritePage(uint16_t pageNumber, uint8_t* data);
+
+    // writes _eraseblockBuffer to flash - overrides Plattform::writeBufferedEraseBlock() for performance optimization only
+    void writeBufferedEraseBlock();
+
+private:
+  void init();
+  uint32_t _MemoryEnd = 0;
+  uint32_t _MemoryStart = 0;
+  uint32_t _pageSize;
+  uint32_t _rowSize;
+  uint32_t _pageCnt;
+
+  uint32_t getRowAddr(uint32_t flasAddr);
+  void write(const volatile void* flash_ptr, const void* data, uint32_t size);
+  void erase(const volatile void* flash_ptr, uint32_t size);
+  void eraseRow(const volatile void* flash_ptr);
+
+#endif
 };
 
 #endif