1 files changed, 68 insertions, 0 deletions
diff --git a/Marlin/src/HAL/STM32/eeprom_sram.cpp b/Marlin/src/HAL/STM32/eeprom_sram.cpp
new file mode 100644
index 0000000..135bcab
--- /dev/null
+++ b/Marlin/src/HAL/STM32/eeprom_sram.cpp
@@ -0,0 +1,68 @@
+/**
+ * Marlin 3D Printer Firmware
+ *
+ * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ * Copyright (c) 2016 Bob Cousins bobcousins42@googlemail.com
+ * Copyright (c) 2015-2016 Nico Tonnhofer wurstnase.reprap@gmail.com
+ * Copyright (c) 2016 Victor Perez victor_pv@hotmail.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#if defined(ARDUINO_ARCH_STM32) && !defined(STM32GENERIC)
+
+#include "../../inc/MarlinConfig.h"
+
+#if ENABLED(SRAM_EEPROM_EMULATION)
+
+#include "../shared/eeprom_if.h"
+#include "../shared/eeprom_api.h"
+
+#ifndef MARLIN_EEPROM_SIZE
+  #define MARLIN_EEPROM_SIZE 0x1000 // 4KB
+#endif
+size_t PersistentStore::capacity()    { return MARLIN_EEPROM_SIZE; }
+
+bool PersistentStore::access_start()  { return true; }
+bool PersistentStore::access_finish() { return true; }
+
+bool PersistentStore::write_data(int &pos, const uint8_t *value, size_t size, uint16_t *crc) {
+  while (size--) {
+    uint8_t v = *value;
+
+    // Save to Backup SRAM
+    *(__IO uint8_t *)(BKPSRAM_BASE + (uint8_t * const)pos) = v;
+
+    crc16(crc, &v, 1);
+    pos++;
+    value++;
+  };
+
+  return false;
+}
+
+bool PersistentStore::read_data(int &pos, uint8_t *value, size_t size, uint16_t *crc, const bool writing/*=true*/) {
+  do {
+    // Read from either external EEPROM, program flash or Backup SRAM
+    const uint8_t c = ( *(__IO uint8_t *)(BKPSRAM_BASE + ((uint8_t*)pos)) );
+    if (writing) *value = c;
+    crc16(crc, &c, 1);
+    pos++;
+    value++;
+  } while (--size);
+  return false;
+}
+
+#endif // SRAM_EEPROM_EMULATION
+#endif // ARDUINO_ARCH_STM32 && !STM32GENERIC