stm32L0xx soc series has an embedded EEPROM

This EEPROM area is mapped in the non volatile memory
and accessed with dedicated HAL functions

Signed-off-by: Francois Ramu <[email protected]>

Author: FRASTM

cores/arduino/stm32/stm32_eeprom.h

@@ -80,7 +80,19 @@ extern "C" {
  */
 #define FLASH_PAGE_SIZE     ((uint32_t)(16*1024)) /* 16kB page */
 #endif
+
+#if defined(STM32L0xx)
+#if !defined (DATA_EEPROM_END)
+/* assuming two contiguous banks */
+#if defined (DATA_EEPROM_BANK2_END)
+#define DATA_EEPROM_END DATA_EEPROM_BANK2_END
+#endif /* DATA_EEPROM_BANK2_END */
+#endif /* !DATA_EEPROM_END */
+#define E2END (DATA_EEPROM_END - DATA_EEPROM_BASE)
+#else /* STM32L0xx */
 #define E2END (FLASH_PAGE_SIZE - 1)
+#endif /* STM32L0xx */
+
 #endif
 
 /* Exported macro ------------------------------------------------------------*/

libraries/EEPROM/src/EEPROM.h

@@ -225,7 +225,11 @@ struct EEPROMClass {
   //Functionality to 'get' and 'put' objects to and from EEPROM.
   template< typename T > T &get(int idx, T &t)
   {
+#if defined (STM32L0xx)
+    EEPtr e = idx + DATA_EEPROM_BASE;
+#else
     EEPtr e = idx;
+#endif /* STM32L0xx */
     uint8_t *ptr = (uint8_t *) &t;
     for (int count = sizeof(T) ; count ; --count, ++e) {
       *ptr++ = *e;
@@ -235,7 +239,11 @@ struct EEPROMClass {
 
   template< typename T > const T &put(int idx, const T &t)
   {
+#if defined (STM32L0xx)
+    EEPtr e = idx + DATA_EEPROM_BASE;
+#else
     EEPtr e = idx;
+#endif /* STM32L0xx */
     const uint8_t *ptr = (const uint8_t *) &t;
     for (int count = sizeof(T) ; count ; --count, ++e) {
       (*e).update(*ptr++);

libraries/SrcWrapper/src/stm32/stm32_eeprom.c

@@ -151,8 +151,17 @@ static uint8_t eeprom_buffer[E2END + 1] __attribute__((aligned(8))) = {0};
   */
 uint8_t eeprom_read_byte(const uint32_t pos)
 {
+#if defined(STM32L0xx)
+  __IO uint8_t data = 0;
+  /* control that pos is a valid address */
+  if (pos <= (DATA_EEPROM_END - DATA_EEPROM_BASE)) {
+    data = *(__IO uint8_t *)(DATA_EEPROM_BASE + pos);
+  }
+  return (uint8_t)data;
+#else
   eeprom_buffer_fill();
   return eeprom_buffered_read_byte(pos);
+#endif /* STM32L0xx */
 }
 
 /**
@@ -163,8 +172,18 @@ uint8_t eeprom_read_byte(const uint32_t pos)
   */
 void eeprom_write_byte(uint32_t pos, uint8_t value)
 {
+#if defined(STM32L0xx)
+  /* control that pos is a valid address */
+  if (pos <= (DATA_EEPROM_END - DATA_EEPROM_BASE)) {
+    if (HAL_FLASHEx_DATAEEPROM_Unlock() == HAL_OK) {
+      HAL_FLASHEx_DATAEEPROM_Program(FLASH_TYPEPROGRAMDATA_BYTE, (pos + DATA_EEPROM_BASE), (uint32_t)value);
+      HAL_FLASHEx_DATAEEPROM_Lock();
+    }
+  }
+#else
   eeprom_buffered_write_byte(pos, value);
   eeprom_buffer_flush();
+#endif /* STM32L0xx */
 }
 
 /**
@@ -195,7 +214,17 @@ void eeprom_buffered_write_byte(uint32_t pos, uint8_t value)
   */
 void eeprom_buffer_fill(void)
 {
+#if defined(STM32L0xx)
+  uint32_t i;
+  __IO uint32_t data;
+
+  for (i = DATA_EEPROM_BASE ; i <= DATA_EEPROM_END ; i++) {
+    data = *(__IO uint32_t *)(DATA_EEPROM_BASE + i);
+    eeprom_buffer[i] = (uint8_t)data;
+  }
+#else
   memcpy(eeprom_buffer, (uint8_t *)(FLASH_BASE_ADDRESS), E2END + 1);
+#endif /* STM32L0xx */
 }
 
 #if defined(EEPROM_RETRAM_MODE)
@@ -210,6 +239,22 @@ void eeprom_buffer_flush(void)
   memcpy((uint8_t *)(FLASH_BASE_ADDRESS), eeprom_buffer, E2END + 1);
 }
 
+#elif defined(STM32L0xx)
+/**
+  * @brief  This function writes the buffer content into the eeprom on L0
+  * @param  none
+  * @retval none
+  */
+void eeprom_buffer_flush(void)
+{
+  uint32_t i;
+
+  for (i = DATA_EEPROM_BASE ; i <= DATA_EEPROM_END ; i++) {
+    HAL_FLASHEx_DATAEEPROM_Unlock();
+    HAL_FLASHEx_DATAEEPROM_Program(FLASH_TYPEPROGRAMDATA_BYTE, i, (uint32_t)eeprom_buffer[i]);
+    HAL_FLASHEx_DATAEEPROM_Lock();
+  }
+}
 #else /* defined(EEPROM_RETRAM_MODE) */
 
 /**