Refine EEPROM types / flags (#17772)

Marlin/src/HAL/AVR/eeprom.cpp

@@ -27,7 +27,8 @@
 
 #include "../shared/eeprom_api.h"
 
-bool PersistentStore::access_start() { return true; }
+size_t PersistentStore::capacity()    { return E2END + 1; }
+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) {
@@ -61,7 +62,5 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t
   return false;  // always assume success for AVR's
 }
 
-size_t PersistentStore::capacity() { return E2END + 1; }
-
 #endif // EEPROM_SETTINGS || SD_FIRMWARE_UPDATE
 #endif // __AVR__

Marlin/src/HAL/DUE/HAL.h

@@ -30,6 +30,7 @@
 #define CPU_32_BIT
 
 #include "../shared/Marduino.h"
+#include "../shared/eeprom_if.h"
 #include "../shared/math_32bit.h"
 #include "../shared/HAL_SPI.h"
 #include "fastio.h"
@@ -130,14 +131,6 @@ void sei();                     // Enable interrupts
 void HAL_clear_reset_source();  // clear reset reason
 uint8_t HAL_get_reset_source(); // get reset reason
 
-//
-// EEPROM
-//
-void eeprom_write_byte(uint8_t *pos, unsigned char value);
-uint8_t eeprom_read_byte(uint8_t *pos);
-void eeprom_read_block (void *__dst, const void *__src, size_t __n);
-void eeprom_update_block (const void *__src, void *__dst, size_t __n);
-
 //
 // ADC
 //

Marlin/src/HAL/DUE/eeprom_flash.cpp

@@ -22,25 +22,26 @@
  */
 #ifdef ARDUINO_ARCH_SAM
 
-#include "../../inc/MarlinConfigPre.h"
+#include "../../inc/MarlinConfig.h"
 
-#if ENABLED(EEPROM_SETTINGS)
+#if ENABLED(FLASH_EEPROM_EMULATION)
 
 #include "../../inc/MarlinConfig.h"
+
+#include "../shared/eeprom_if.h"
 #include "../shared/eeprom_api.h"
 
-#if !defined(E2END) && ENABLED(FLASH_EEPROM_EMULATION)
+#if !defined(E2END)
   #define E2END 0xFFF // Default to Flash emulated EEPROM size (EepromEmulation_Due.cpp)
 #endif
 
 extern void eeprom_flush();
 
-bool PersistentStore::access_start() { return true; }
+size_t PersistentStore::capacity()    { return E2END + 1; }
+bool PersistentStore::access_start()  { return true; }
 
 bool PersistentStore::access_finish() {
-  #if ENABLED(FLASH_EEPROM_EMULATION)
+  eeprom_flush();
-    eeprom_flush();
-  #endif
   return true;
 }
 
@@ -76,7 +77,5 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t
   return false;
 }
 
-size_t PersistentStore::capacity() { return E2END + 1; }
-
 #endif // EEPROM_SETTINGS
 #endif // ARDUINO_ARCH_SAM

Marlin/src/HAL/DUE/eeprom_if_flash.cpp

@@ -57,6 +57,7 @@
 #if ENABLED(FLASH_EEPROM_EMULATION)
 
 #include "../shared/Marduino.h"
+#include "../shared/eeprom_if.h"
 #include "../shared/eeprom_api.h"
 
 #define EEPROMSize     4096

Marlin/src/HAL/DUE/eeprom_wired.cpp

@@ -0,0 +1,69 @@
+/**
+ * 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 <http://www.gnu.org/licenses/>.
+ *
+ */
+#ifdef ARDUINO_ARCH_SAM
+
+#include "../../inc/MarlinConfig.h"
+
+#if USE_WIRED_EEPROM
+
+#include "../shared/eeprom_if.h"
+#include "../shared/eeprom_api.h"
+
+size_t PersistentStore::capacity()    { return E2END + 1; }
+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 * const p = (uint8_t * const)pos;
+    uint8_t v = *value;
+    // EEPROM has only ~100,000 write cycles,
+    // so only write bytes that have changed!
+    if (v != eeprom_read_byte(p)) {
+      eeprom_write_byte(p, v);
+      delay(2);
+      if (eeprom_read_byte(p) != v) {
+        SERIAL_ECHO_MSG(STR_ERR_EEPROM_WRITE);
+        return true;
+      }
+    }
+    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 {
+    uint8_t c = eeprom_read_byte((uint8_t*)pos);
+    if (writing) *value = c;
+    crc16(crc, &c, 1);
+    pos++;
+    value++;
+  } while (--size);
+  return false;
+}
+
+#endif // USE_WIRED_EEPROM
+#endif // ARDUINO_ARCH_SAM

Marlin/src/HAL/DUE/inc/Conditionals_post.h

@@ -22,7 +22,7 @@
 #pragma once
 
 #if USE_FALLBACK_EEPROM
-  #undef SRAM_EEPROM_EMULATION
-  #undef SDCARD_EEPROM_EMULATION
   #define FLASH_EEPROM_EMULATION
+#elif EITHER(I2C_EEPROM, SPI_EEPROM)
+  #define USE_SHARED_EEPROM 1
 #endif

Marlin/src/HAL/ESP32/HAL.h

@@ -109,12 +109,6 @@ int freeMemory();
 
 void analogWrite(pin_t pin, int value);
 
-// EEPROM
-void eeprom_write_byte(uint8_t *pos, unsigned char value);
-uint8_t eeprom_read_byte(uint8_t *pos);
-void eeprom_read_block (void *__dst, const void *__src, size_t __n);
-void eeprom_update_block (const void *__src, void *__dst, size_t __n);
-
 // ADC
 #define HAL_ANALOG_SELECT(pin)
 

Marlin/src/HAL/ESP32/eeprom.cpp

@@ -23,7 +23,7 @@
 
 #include "../../inc/MarlinConfig.h"
 
-#if USE_WIRED_EEPROM
+#if ENABLED(EEPROM_SETTINGS)
 
 #include "../shared/eeprom_api.h"
 #include <EEPROM.h>
@@ -58,5 +58,5 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t
 
 size_t PersistentStore::capacity() { return EEPROM_SIZE; }
 
-#endif // USE_WIRED_EEPROM
+#endif // EEPROM_SETTINGS
 #endif // ARDUINO_ARCH_ESP32

Marlin/src/HAL/ESP32/inc/Conditionals_post.h

@@ -20,8 +20,3 @@
  *
  */
 #pragma once
-
-#undef USE_WIRED_EEPROM
-#if ENABLED(EEPROM_SETTINGS) && DISABLED(FLASH_EEPROM_EMULATION)
-  #define USE_WIRED_EEPROM 1
-#endif

Marlin/src/HAL/LINUX/arduino.cpp

@@ -75,20 +75,6 @@ uint16_t analogRead(pin_t adc_pin) {
   return Gpio::get(DIGITAL_PIN_TO_ANALOG_PIN(adc_pin));
 }
 
-// **************************
-// Persistent Config Storage
-// **************************
-
-void eeprom_write_byte(unsigned char *pos, unsigned char value) {
-
-}
-
-unsigned char eeprom_read_byte(uint8_t * pos) { return '\0'; }
-
-void eeprom_read_block(void *__dst, const void *__src, size_t __n) { }
-
-void eeprom_update_block(const void *__src, void *__dst, size_t __n) { }
-
 char *dtostrf(double __val, signed char __width, unsigned char __prec, char *__s) {
   char format_string[20];
   snprintf(format_string, 20, "%%%d.%df", __width, __prec);

Marlin/src/HAL/LINUX/include/Arduino.h

@@ -106,12 +106,6 @@ bool digitalRead(pin_t);
 void analogWrite(pin_t, int);
 uint16_t analogRead(pin_t);
 
-// EEPROM
-void eeprom_write_byte(unsigned char *pos, unsigned char value);
-unsigned char eeprom_read_byte(unsigned char *pos);
-void eeprom_read_block(void *__dst, const void *__src, size_t __n);
-void eeprom_update_block(const void *__src, void *__dst, size_t __n);
-
 int32_t random(int32_t);
 int32_t random(int32_t, int32_t);
 void randomSeed(uint32_t);

Marlin/src/HAL/LPC1768/eeprom_flash.cpp

@@ -58,6 +58,8 @@ static uint8_t ram_eeprom[EEPROM_SIZE] __attribute__((aligned(4))) = {0};
 static bool eeprom_dirty = false;
 static int current_slot = 0;
 
+size_t PersistentStore::capacity() { return EEPROM_SIZE; }
+
 bool PersistentStore::access_start() {
   uint32_t first_nblank_loc, first_nblank_val;
   IAP_STATUS_CODE status;
@@ -122,7 +124,5 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t
   return false;  // return true for any error
 }
 
-size_t PersistentStore::capacity() { return EEPROM_SIZE; }
-
 #endif // FLASH_EEPROM_EMULATION
 #endif // TARGET_LPC1768

Marlin/src/HAL/LPC1768/eeprom_sdcard.cpp

@@ -38,6 +38,8 @@ FATFS fat_fs;
 FIL eeprom_file;
 bool eeprom_file_open = false;
 
+size_t PersistentStore::capacity() { return 4096; } // 4KiB of Emulated EEPROM
+
 bool PersistentStore::access_start() {
   const char eeprom_erase_value = 0xFF;
   MSC_Aquire_Lock();
@@ -168,7 +170,5 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, const size_t size, uin
   return bytes_read != size;  // return true for any error
 }
 
-size_t PersistentStore::capacity() { return 4096; } // 4KiB of Emulated EEPROM
-
 #endif // SDCARD_EEPROM_EMULATION
 #endif // TARGET_LPC1768

Marlin/src/HAL/LPC1768/eeprom_wired.cpp

@@ -19,19 +19,14 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-
-/**
- * I2C/SPI EEPROM interface for LPC1768
- */
-
 #ifdef TARGET_LPC1768
 
 #include "../../inc/MarlinConfig.h"
 
 #if USE_WIRED_EEPROM
 
+#include "../shared/eeprom_if.h"
 #include "../shared/eeprom_api.h"
-#include <Wire.h>
 
 #ifndef EEPROM_SIZE
   #define EEPROM_SIZE           0x8000 // 32kB‬

Marlin/src/HAL/LPC1768/inc/Conditionals_post.h

@@ -21,8 +21,6 @@
  */
 #pragma once
 
-#undef I2C_EEPROM // Arduino framework provides code for I2C
-
 #if USE_FALLBACK_EEPROM
   #define FLASH_EEPROM_EMULATION
 #endif

Marlin/src/HAL/SAMD51/HAL.h

@@ -113,12 +113,6 @@ typedef int8_t pin_t;
 void HAL_clear_reset_source();  // clear reset reason
 uint8_t HAL_get_reset_source(); // get reset reason
 
-//
-// EEPROM
-//
-void eeprom_write_byte(uint8_t *pos, unsigned char value);
-uint8_t eeprom_read_byte(uint8_t *pos);
-
 //
 // ADC
 //

Marlin/src/HAL/SAMD51/eeprom_wired.cpp

@@ -18,18 +18,17 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-
 #ifdef __SAMD51__
 
 #include "../../inc/MarlinConfig.h"
 
-#if ENABLED(EEPROM_SETTINGS) && NONE(QSPI_EEPROM, FLASH_EEPROM_EMULATION)
+#if USE_WIRED_EEPROM
 
+#include "../shared/eeprom_if.h"
 #include "../shared/eeprom_api.h"
 
-size_t PersistentStore::capacity() { return E2END + 1; }
+size_t PersistentStore::capacity()    { return E2END + 1; }
-
+bool PersistentStore::access_start()  { return true; }
-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) {
@@ -62,5 +61,5 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t
   return false;
 }
 
-#endif // EEPROM_SETTINGS && !(QSPI_EEPROM || FLASH_EEPROM_EMULATION)
+#endif // USE_WIRED_EEPROM
 #endif // __SAMD51__

Marlin/src/HAL/SAMD51/inc/Conditionals_post.h

@@ -23,4 +23,6 @@
 
 #if USE_FALLBACK_EEPROM
   #define FLASH_EEPROM_EMULATION
+#elif EITHER(I2C_EEPROM, SPI_EEPROM)
+  #define USE_SHARED_EEPROM 1
 #endif

Marlin/src/HAL/STM32/HAL.h

@@ -191,16 +191,6 @@ static inline int freeMemory() {
 
 #pragma GCC diagnostic pop
 
-//
-// EEPROM
-//
-
-// Wire library should work for i2c EEPROMs
-void eeprom_write_byte(uint8_t *pos, unsigned char value);
-uint8_t eeprom_read_byte(uint8_t *pos);
-void eeprom_read_block(void *__dst, const void *__src, size_t __n);
-void eeprom_update_block(const void *__src, void *__dst, size_t __n);
-
 //
 // ADC
 //

Marlin/src/HAL/STM32/eeprom_flash.cpp

@@ -24,7 +24,7 @@
 
 #include "../../inc/MarlinConfig.h"
 
-#if BOTH(EEPROM_SETTINGS, FLASH_EEPROM_EMULATION)
+#if ENABLED(FLASH_EEPROM_EMULATION)
 
 #include "../shared/eeprom_api.h"
 
@@ -235,13 +235,7 @@ bool PersistentStore::write_data(int &pos, const uint8_t *value, size_t size, ui
 
 bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t *crc, const bool writing/*=true*/) {
   do {
-    const uint8_t c = (
+    const uint8_t c = TERN(FLASH_EEPROM_LEVELING, ram_eeprom[pos], eeprom_buffered_read_byte(pos));
-      #if ENABLED(FLASH_EEPROM_LEVELING)
-        ram_eeprom[pos]
-      #else
-        eeprom_buffered_read_byte(pos)
-      #endif
-    );
     if (writing) *value = c;
     crc16(crc, &c, 1);
     pos++;
@@ -251,14 +245,8 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t
 }
 
 size_t PersistentStore::capacity() {
-  return (
+  return TERN(FLASH_EEPROM_LEVELING, EEPROM_SIZE, E2END + 1);
-    #if ENABLED(FLASH_EEPROM_LEVELING)
-      EEPROM_SIZE
-    #else
-      E2END + 1
-    #endif
-  );
 }
 
-#endif // EEPROM_SETTINGS && FLASH_EEPROM_EMULATION
+#endif // FLASH_EEPROM_EMULATION
 #endif // ARDUINO_ARCH_STM32 && !STM32GENERIC

Marlin/src/HAL/STM32/eeprom_sram.cpp

@@ -0,0 +1,64 @@
+/**
+ * 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 <http://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"
+
+size_t PersistentStore::capacity()    { return 4096; } // 4K of SRAM
+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

Marlin/src/HAL/STM32/eeprom_wired.cpp

@@ -24,10 +24,13 @@
 
 #include "../../inc/MarlinConfig.h"
 
-#if EITHER(USE_WIRED_EEPROM, SRAM_EEPROM_EMULATION)
+#if USE_WIRED_EEPROM
 
+
+#include "../shared/eeprom_if.h"
 #include "../shared/eeprom_api.h"
 
+size_t PersistentStore::capacity()    { return E2END + 1; }
 bool PersistentStore::access_start()  { return true; }
 bool PersistentStore::access_finish() { return true; }
 
@@ -35,21 +38,16 @@ bool PersistentStore::write_data(int &pos, const uint8_t *value, size_t size, ui
   while (size--) {
     uint8_t v = *value;
 
-    // Save to either external EEPROM, program flash or Backup SRAM
+    // EEPROM has only ~100,000 write cycles,
-    #if USE_WIRED_EEPROM
+    // so only write bytes that have changed!
-      // EEPROM has only ~100,000 write cycles,
+    uint8_t * const p = (uint8_t * const)pos;
-      // so only write bytes that have changed!
+    if (v != eeprom_read_byte(p)) {
-      uint8_t * const p = (uint8_t * const)pos;
+      eeprom_write_byte(p, v);
-      if (v != eeprom_read_byte(p)) {
+      if (eeprom_read_byte(p) != v) {
-        eeprom_write_byte(p, v);
+        SERIAL_ECHO_MSG(STR_ERR_EEPROM_WRITE);
-        if (eeprom_read_byte(p) != v) {
+        return true;
-          SERIAL_ECHO_MSG(STR_ERR_EEPROM_WRITE);
-          return true;
-        }
       }
-    #else
+    }
-      *(__IO uint8_t *)(BKPSRAM_BASE + (uint8_t * const)pos) = v;
-    #endif
 
     crc16(crc, &v, 1);
     pos++;
@@ -62,14 +60,7 @@ bool PersistentStore::write_data(int &pos, const uint8_t *value, size_t size, ui
 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 = (
+    const uint8_t c = eeprom_read_byte((uint8_t*)pos);
-      #if USE_WIRED_EEPROM
-        eeprom_read_byte((uint8_t*)pos)
-      #else
-        (*(__IO uint8_t *)(BKPSRAM_BASE + ((uint8_t*)pos)))
-      #endif
-    );
-
     if (writing) *value = c;
     crc16(crc, &c, 1);
     pos++;
@@ -78,9 +69,5 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t
   return false;
 }
 
-size_t PersistentStore::capacity() {
+#endif // USE_WIRED_EEPROM
-  return TERN(USE_WIRED_EEPROM, E2END + 1, 4096); // 4K for emulated
-}
-
-#endif // USE_WIRED_EEPROM || SRAM_EEPROM_EMULATION
 #endif // ARDUINO_ARCH_STM32 && !STM32GENERIC

Marlin/src/HAL/STM32/inc/Conditionals_post.h

@@ -24,4 +24,6 @@
 // If no real or emulated EEPROM selected, fall back to SD emulation
 #if USE_FALLBACK_EEPROM
   #define SDCARD_EEPROM_EMULATION
+#elif EITHER(I2C_EEPROM, SPI_EEPROM)
+  #define USE_SHARED_EEPROM 1
 #endif

Marlin/src/HAL/STM32F1/HAL.h

@@ -248,19 +248,6 @@ static int freeMemory() {
 
 #pragma GCC diagnostic pop
 
-//
-// EEPROM
-//
-
-/**
- * TODO: Write all this EEPROM stuff. Can emulate EEPROM in flash as last resort.
- * Wire library should work for i2c EEPROMs.
- */
-void eeprom_write_byte(uint8_t *pos, unsigned char value);
-uint8_t eeprom_read_byte(uint8_t *pos);
-void eeprom_read_block(void *__dst, const void *__src, size_t __n);
-void eeprom_update_block(const void *__src, void *__dst, size_t __n);
-
 //
 // ADC
 //

Marlin/src/HAL/STM32F1/eeprom_wired.cpp

@@ -23,8 +23,11 @@
 
 #if USE_WIRED_EEPROM
 
+#include "../shared/eeprom_if.h"
 #include "../shared/eeprom_api.h"
 
+size_t PersistentStore::capacity()    { return E2END + 1; }
+
 bool PersistentStore::access_start() {
   #if ENABLED(SPI_EEPROM)
     #if SPI_CHAN_EEPROM1 == 1
@@ -70,7 +73,5 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t
   return false;
 }
 
-size_t PersistentStore::capacity() { return E2END + 1; }
-
 #endif // USE_WIRED_EEPROM
 #endif // __STM32F1__

Marlin/src/HAL/STM32F1/inc/Conditionals_post.h

@@ -24,4 +24,6 @@
 // If no real EEPROM, Flash emulation, or SRAM emulation is available fall back to SD emulation
 #if USE_FALLBACK_EEPROM
   #define SDCARD_EEPROM_EMULATION
+#elif EITHER(I2C_EEPROM, SPI_EEPROM)
+  #define USE_SHARED_EEPROM 1
 #endif

Marlin/src/HAL/STM32_F4_F7/HAL.h

@@ -51,6 +51,8 @@
   #error "SERIAL_PORT cannot be 0. (Port 0 does not exist.) Please update your configuration."
 #elif SERIAL_PORT == -1
   #define MYSERIAL0 SerialUSB
+#elif SERIAL_PORT == 0
+  #define MYSERIAL0 Serial1
 #elif SERIAL_PORT == 1
   #define MYSERIAL0 SerialUART1
 #elif SERIAL_PORT == 2
@@ -74,6 +76,8 @@
     #error "SERIAL_PORT_2 must be different than SERIAL_PORT. Please update your configuration."
   #elif SERIAL_PORT_2 == -1
     #define MYSERIAL1 SerialUSB
+  #elif SERIAL_PORT_2 == 0
+    #define MYSERIAL1 Serial1
   #elif SERIAL_PORT_2 == 1
     #define MYSERIAL1 SerialUART1
   #elif SERIAL_PORT_2 == 2
@@ -103,6 +107,8 @@
     #error "DGUS_SERIAL_PORT must be different than SERIAL_PORT_2. Please update your configuration."
   #elif DGUS_SERIAL_PORT == -1
     #define DGUS_SERIAL SerialUSB
+  #elif DGUS_SERIAL_PORT == 0
+    #define DGUS_SERIAL Serial1
   #elif DGUS_SERIAL_PORT == 1
     #define DGUS_SERIAL SerialUART1
   #elif DGUS_SERIAL_PORT == 2
@@ -206,19 +212,6 @@ static inline int freeMemory() {
 
 #pragma GCC diagnostic pop
 
-//
-// EEPROM
-//
-
-/**
- * TODO: Write all this EEPROM stuff. Can emulate EEPROM in flash as last resort.
- * Wire library should work for i2c EEPROMs.
- */
-void eeprom_write_byte(uint8_t *pos, unsigned char value);
-uint8_t eeprom_read_byte(uint8_t *pos);
-void eeprom_read_block (void *__dst, const void *__src, size_t __n);
-void eeprom_update_block (const void *__src, void *__dst, size_t __n);
-
 //
 // ADC
 //

Marlin/src/HAL/STM32_F4_F7/HAL_SPI.cpp

@@ -20,6 +20,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
+#if defined(STM32GENERIC) && (defined(STM32F4) || defined(STM32F7))
 
 /**
  * Software SPI functions originally from Arduino Sd2Card Library
@@ -30,8 +31,6 @@
  * Adapted to the Marlin STM32F4/7 HAL
  */
 
-#if defined(STM32GENERIC) && (defined(STM32F4) || defined(STM32F7))
-
 #include "../../inc/MarlinConfig.h"
 
 #include <SPI.h>
@@ -121,7 +120,7 @@ uint8_t spiRec() {
  */
 void spiRead(uint8_t* buf, uint16_t nbyte) {
   SPI.beginTransaction(spiConfig);
-  #ifdef STM32GENERIC
+  #ifndef STM32GENERIC
     SPI.dmaTransfer(0, const_cast<uint8_t*>(buf), nbyte);
   #else
     SPI.transfer((uint8_t*)buf, nbyte);
@@ -153,7 +152,7 @@ void spiSend(uint8_t b) {
 void spiSendBlock(uint8_t token, const uint8_t* buf) {
   SPI.beginTransaction(spiConfig);
   SPI.transfer(token);
-  #ifdef STM32GENERIC
+  #ifndef STM32GENERIC
     SPI.dmaSend(const_cast<uint8_t*>(buf), 512);
   #else
     SPI.transfer((uint8_t*)buf, nullptr, 512);

Marlin/src/HAL/STM32_F4_F7/eeprom.cpp

@@ -22,13 +22,15 @@
  */
 #if defined(STM32GENERIC) && (defined(STM32F4) || defined(STM32F7))
 
-#include "../../inc/MarlinConfigPre.h"
+#include "../../inc/MarlinConfig.h"
 
 #if ENABLED(EEPROM_SETTINGS)
 
+#include "../shared/eeprom_if.h"
 #include "../shared/eeprom_api.h"
 
-bool PersistentStore::access_start() { return true; }
+size_t PersistentStore::capacity()    { return E2END + 1; }
+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) {
@@ -62,7 +64,5 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t
   return false;
 }
 
-size_t PersistentStore::capacity() { return E2END + 1; }
-
 #endif // EEPROM_SETTINGS
 #endif // STM32GENERIC && (STM32F4 || STM32F7)

Marlin/src/HAL/STM32_F4_F7/eeprom_emul.cpp

@@ -1,6 +1,6 @@
 /**
   ******************************************************************************
-  * @file    EEPROM/EEPROM_Emulation/src/eeprom.c
+  * @file    eeprom_emul.cpp
   * @author  MCD Application Team
   * @version V1.2.6
   * @date    04-November-2016
@@ -49,6 +49,10 @@
   */
 #if defined(STM32GENERIC) && (defined(STM32F4) || defined(STM32F7))
 
+#include "../../inc/MarlinConfigPre.h"
+
+#if ENABLED(FLASH_EEPROM_EMULATION)
+
 /* Includes ------------------------------------------------------------------*/
 #include "eeprom_emul.h"
 
@@ -518,6 +522,7 @@ static uint16_t EE_PageTransfer(uint16_t VirtAddress, uint16_t Data) {
   return HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, NewPageAddress, VALID_PAGE);
 }
 
+#endif // FLASH_EEPROM_EMULATION
 #endif // STM32GENERIC && (STM32F4 || STM32F7)
 
 /**

Marlin/src/HAL/STM32_F4_F7/eeprom_if_flash.cpp

@@ -16,12 +16,10 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-
 #if defined(STM32GENERIC) && (defined(STM32F4) || defined(STM32F7))
 
 /**
- * Description: Functions for a Flash emulated EEPROM
+ * Arduino-style interface for Flash emulated EEPROM
- * Not platform dependent.
  */
 
 // Include configs and pins to get all EEPROM flags
@@ -35,6 +33,7 @@
 
 #include "HAL.h"
 #include "eeprom_emul.h"
+#include "../shared/eeprom_if.h"
 
 // ------------------------
 // Local defines

Marlin/src/HAL/TEENSY35_36/eeprom.cpp

@@ -29,7 +29,8 @@
 #include "../shared/eeprom_api.h"
 #include <avr/eeprom.h>
 
-bool PersistentStore::access_start() { return true; }
+size_t PersistentStore::capacity()    { return E2END + 1; }
+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) {
@@ -63,7 +64,5 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, size_t size, uint16_t
   return false;
 }
 
-size_t PersistentStore::capacity() { return E2END + 1; }
-
 #endif // USE_WIRED_EEPROM
 #endif // __MK64FX512__ || __MK66FX1M0__

Marlin/src/HAL/shared/eeprom_if.h

@@ -0,0 +1,30 @@
+/**
+ * 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
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+//
+// EEPROM
+//
+void eeprom_write_byte(uint8_t *pos, unsigned char value);
+uint8_t eeprom_read_byte(uint8_t *pos);
+void eeprom_read_block(void *__dst, const void *__src, size_t __n);
+void eeprom_update_block(const void *__src, void *__dst, size_t __n);

Marlin/src/HAL/shared/eeprom_if_i2c.cpp

@@ -21,20 +21,19 @@
  */
 
 /**
- * Description: functions for I2C connected external EEPROM.
+ * Platform-independent Arduino functions for I2C EEPROM.
- * Not platform dependent.
+ * Enable USE_SHARED_EEPROM if not supplied by the framework.
- *
- * TODO: Some platform Arduino libraries define these functions
- *       so Marlin needs to add a glue layer to prevent the conflict.
  */
 
 #include "../../inc/MarlinConfig.h"
 
-#if ENABLED(I2C_EEPROM)
+#if BOTH(USE_SHARED_EEPROM, I2C_EEPROM)
 
 #include "../HAL.h"
 #include <Wire.h>
 
+#include "eeprom_if.h"
+
 #ifndef EEPROM_WRITE_DELAY
   #define EEPROM_WRITE_DELAY    5
 #endif
@@ -126,4 +125,4 @@ void eeprom_read_block(void* pos, const void *__dst, size_t n) {
     if (Wire.available()) *((uint8_t*)pos + c) = Wire.read();
 }
 
-#endif // I2C_EEPROM
+#endif // USE_SHARED_EEPROM && I2C_EEPROM

Marlin/src/HAL/shared/eeprom_if_spi.cpp

@@ -21,15 +21,16 @@
  */
 
 /**
- * Description: functions for SPI connected external EEPROM.
+ * Platform-independent Arduino functions for SPI EEPROM.
- * Not platform dependent.
+ * Enable USE_SHARED_EEPROM if not supplied by the framework.
  */
 
 #include "../../inc/MarlinConfig.h"
 
-#if ENABLED(SPI_EEPROM)
+#if BOTH(USE_SHARED_EEPROM, SPI_EEPROM)
 
 #include "../HAL.h"
+#include "eeprom_if.h"
 
 #define CMD_WREN  6   // WREN
 #define CMD_READ  2   // WRITE
@@ -119,4 +120,4 @@ void eeprom_update_block(const void* src, void* eeprom_address, size_t n) {
   delay(EEPROM_WRITE_DELAY);   // wait for page write to complete
 }
 
-#endif // SPI_EEPROM
+#endif // USE_SHARED_EEPROM && I2C_EEPROM

Marlin/src/inc/Conditionals_adv.h

@@ -337,3 +337,8 @@
 #else
   #define SD_CONNECTION_IS(...) 0
 #endif
+
+// Flag if an EEPROM type is pre-selected
+#if ENABLED(EEPROM_SETTINGS) && NONE(I2C_EEPROM, SPI_EEPROM, QSPI_EEPROM, FLASH_EEPROM_EMULATION, SRAM_EEPROM_EMULATION, SDCARD_EEPROM_EMULATION)
+  #define NO_EEPROM_SELECTED 1
+#endif

Marlin/src/inc/SanityCheck.h

@@ -2054,8 +2054,12 @@ static_assert(hbm[Z_AXIS] >= 0, "HOMING_BUMP_MM.Z must be greater than or equal
 /**
  * Make sure only one EEPROM type is enabled
  */
-#if ENABLED(EEPROM_SETTINGS) && 1 < ENABLED(SDCARD_EEPROM_EMULATION) + ENABLED(FLASH_EEPROM_EMULATION) + ENABLED(SRAM_EEPROM_EMULATION)
+#if ENABLED(EEPROM_SETTINGS)
-  #error "Please select only one of SDCARD, FLASH, or SRAM_EEPROM_EMULATION."
+  #if 1 < 0 \
+    + ENABLED(I2C_EEPROM) + ENABLED(SPI_EEPROM) + ENABLED(QSPI_EEPROM) \
+    + ENABLED(SDCARD_EEPROM_EMULATION) + ENABLED(FLASH_EEPROM_EMULATION) + ENABLED(SRAM_EEPROM_EMULATION)
+    #error "Please select only one method of EEPROM Persistent Storage."
+  #endif
 #endif
 
 /**

Marlin/src/module/printcounter.h

@@ -28,12 +28,8 @@
 // Print debug messages with M111 S2
 //#define DEBUG_PRINTCOUNTER
 
-#if USE_WIRED_EEPROM
+// Round up I2C / SPI address to next page boundary (assuming 32 byte pages)
-  // round up address to next page boundary (assuming 32 byte pages)
+#define STATS_EEPROM_ADDRESS TERN(USE_WIRED_EEPROM, 0x40, 0x32)
-  #define STATS_EEPROM_ADDRESS 0x40
-#else
-  #define STATS_EEPROM_ADDRESS 0x32
-#endif
 
 struct printStatistics {    // 16 bytes
   //const uint8_t magic;    // Magic header, it will always be 0x16
@@ -57,7 +53,7 @@ class PrintCounter: public Stopwatch {
   private:
     typedef Stopwatch super;
 
-    #if USE_WIRED_EEPROM || defined(CPU_32_BIT)
+    #if EITHER(USE_WIRED_EEPROM, CPU_32_BIT)
       typedef uint32_t eeprom_address_t;
     #else
       typedef uint16_t eeprom_address_t;

Marlin/src/pins/stm32f0/pins_MALYAN_M300.h

@@ -31,7 +31,9 @@
 //
 // EEPROM Emulation
 //
-#define FLASH_EEPROM_EMULATION
+#if NO_EEPROM_SELECTED
+  #define FLASH_EEPROM_EMULATION
+#endif
 
 //
 // SD CARD SPI

Marlin/src/pins/stm32f1/pins_BTT_SKR_E3_DIP.h

@@ -33,11 +33,13 @@
 // Ignore temp readings during development.
 //#define BOGUS_TEMPERATURE_GRACE_PERIOD 2000
 
-#define FLASH_EEPROM_EMULATION
+#if EITHER(NO_EEPROM_SELECTED, FLASH_EEPROM_EMULATION)
-#define EEPROM_PAGE_SIZE     (0x800U) // 2KB
+  #define FLASH_EEPROM_EMULATION
-#define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
+  #define EEPROM_PAGE_SIZE     (0x800U) // 2KB
-#undef E2END
+  #define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
-#define E2END                (EEPROM_PAGE_SIZE - 1) // 2KB
+  #undef E2END
+  #define E2END                (EEPROM_PAGE_SIZE - 1) // 2KB
+#endif
 
 //
 // Servos

Marlin/src/pins/stm32f1/pins_BTT_SKR_MINI_E3.h

@@ -31,11 +31,13 @@
 // Ignore temp readings during development.
 //#define BOGUS_TEMPERATURE_GRACE_PERIOD 2000
 
-#define FLASH_EEPROM_EMULATION
+#if EITHER(NO_EEPROM_SELECTED, FLASH_EEPROM_EMULATION)
-#define EEPROM_PAGE_SIZE     (0x800U) // 2KB
+  #define FLASH_EEPROM_EMULATION
-#define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
+  #define EEPROM_PAGE_SIZE     (0x800U) // 2KB
-#undef E2END
+  #define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
-#define E2END                (EEPROM_PAGE_SIZE - 1) // 2KB
+  #undef E2END
+  #define E2END                (EEPROM_PAGE_SIZE - 1) // 2KB
+#endif
 
 //
 // Servos

Marlin/src/pins/stm32f1/pins_BTT_SKR_MINI_V1_1.h

@@ -33,10 +33,12 @@
 // Ignore temp readings during development.
 //#define BOGUS_TEMPERATURE_GRACE_PERIOD 2000
 
-#define FLASH_EEPROM_EMULATION
+#if EITHER(NO_EEPROM_SELECTED, FLASH_EEPROM_EMULATION)
-#define EEPROM_PAGE_SIZE     (0x800U) // 2KB
+  #define FLASH_EEPROM_EMULATION
-#define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
+  #define EEPROM_PAGE_SIZE     (0x800U) // 2KB
-#define E2END                (EEPROM_PAGE_SIZE - 1)
+  #define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
+  #define E2END                (EEPROM_PAGE_SIZE - 1)
+#endif
 
 //
 // Limit Switches

Marlin/src/pins/stm32f1/pins_FYSETC_AIO_II.h

@@ -38,11 +38,13 @@
 //
 // Flash EEPROM Emulation
 //
-#define FLASH_EEPROM_EMULATION
+#if EITHER(NO_EEPROM_SELECTED, FLASH_EEPROM_EMULATION)
-#define EEPROM_PAGE_SIZE     (0x800U) // 2KB
+  #define FLASH_EEPROM_EMULATION
-#define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
+  #define EEPROM_PAGE_SIZE     (0x800U) // 2KB
-#undef E2END
+  #define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
-#define E2END                (EEPROM_PAGE_SIZE - 1) // 2KB
+  #undef E2END
+  #define E2END                (EEPROM_PAGE_SIZE - 1) // 2KB
+#endif
 
 //
 // Limit Switches

Marlin/src/pins/stm32f1/pins_FYSETC_CHEETAH.h

@@ -35,11 +35,13 @@
 
 #define DISABLE_JTAG
 
-#define FLASH_EEPROM_EMULATION
+#if EITHER(NO_EEPROM_SELECTED, FLASH_EEPROM_EMULATION)
-#define EEPROM_PAGE_SIZE     (0x800U) // 2KB
+  #define FLASH_EEPROM_EMULATION
-#define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
+  #define EEPROM_PAGE_SIZE     (0x800U) // 2KB
-#undef E2END
+  #define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
-#define E2END                (EEPROM_PAGE_SIZE - 1) // 2KB
+  #undef E2END
+  #define E2END                (EEPROM_PAGE_SIZE - 1) // 2KB
+#endif
 
 //
 // Servos

Marlin/src/pins/stm32f1/pins_GTM32_MINI.h

@@ -52,8 +52,10 @@
 //#define BOGUS_TEMPERATURE_GRACE_PERIOD 2000
 
 // Enable EEPROM Emulation for this board as it doesn't have EEPROM
-#define FLASH_EEPROM_EMULATION
+#if EITHER(NO_EEPROM_SELECTED, FLASH_EEPROM_EMULATION)
-#define E2END 0xFFF                               // 4KB
+  #define FLASH_EEPROM_EMULATION
+  #define E2END 0xFFF                             // 4KB
+#endif
 
 //
 // Limit Switches

Marlin/src/pins/stm32f1/pins_GTM32_MINI_A30.h

@@ -52,8 +52,10 @@
 //#define BOGUS_TEMPERATURE_GRACE_PERIOD 2000
 
 // Enable EEPROM Emulation for this board as it doesn't have EEPROM
-#define FLASH_EEPROM_EMULATION
+#if EITHER(NO_EEPROM_SELECTED, FLASH_EEPROM_EMULATION)
-#define E2END 0xFFF                               // 4KB
+  #define FLASH_EEPROM_EMULATION
+  #define E2END 0xFFF                             // 4KB
+#endif
 
 //
 // Limit Switches

Marlin/src/pins/stm32f1/pins_GTM32_PRO_VB.h

@@ -52,8 +52,10 @@
 //#define BOGUS_TEMPERATURE_GRACE_PERIOD 2000
 
 // Enable EEPROM Emulation for this board as it doesn't have EEPROM
-#define FLASH_EEPROM_EMULATION
+#if EITHER(NO_EEPROM_SELECTED, FLASH_EEPROM_EMULATION)
-#define E2END 0xFFF                               // 4KB
+  #define FLASH_EEPROM_EMULATION
+  #define E2END 0xFFF                             // 4KB
+#endif
 
 //
 // Limit Switches

Marlin/src/pins/stm32f1/pins_GTM32_REV_B.h

@@ -52,8 +52,10 @@
 //#define BOGUS_TEMPERATURE_GRACE_PERIOD 2000
 
 // Enable EEPROM Emulation for this board as it doesn't have EEPROM
-#define FLASH_EEPROM_EMULATION
+#if EITHER(NO_EEPROM_SELECTED, FLASH_EEPROM_EMULATION)
-#define E2END 0xFFF                               // 4KB
+  #define FLASH_EEPROM_EMULATION
+  #define E2END 0xFFF                             // 4KB
+#endif
 
 //
 // Limit Switches

Marlin/src/pins/stm32f1/pins_JGAURORA_A5S_A1.h

@@ -44,9 +44,11 @@
 
 //#define I2C_EEPROM                              // AT24C64
 //#define E2END 0x7FFFUL                          // 64KB
+
 //#define FLASH_EEPROM_EMULATION
 //#define E2END 0xFFFUL                           // 4KB
 //#define E2END (EEPROM_START_ADDRESS + (EEPROM_PAGE_SIZE) * 2UL - 1UL)
+
 //#define EEPROM_CHITCHAT
 //#define DEBUG_EEPROM_READWRITE
 

Marlin/src/pins/stm32f1/pins_LONGER3D_LK.h

@@ -147,8 +147,10 @@
 // Persistent Storage
 // If no option is selected below the SD Card will be used
 //
-//#define SPI_EEPROM
+#if NO_EEPROM_SELECTED
-#define FLASH_EEPROM_EMULATION
+  //#define SPI_EEPROM
+  #define FLASH_EEPROM_EMULATION
+#endif
 
 #undef E2END
 #if ENABLED(SPI_EEPROM)

Marlin/src/pins/stm32f1/pins_MALYAN_M200.h

@@ -31,10 +31,10 @@
 
 #define BOARD_INFO_NAME "Malyan M200"
 
-// Enable EEPROM Emulation for this board
+// Assume Flash EEPROM
-// This setting should probably be in configuration.h
+#if NO_EEPROM_SELECTED
-// but it is literally the only board which uses it.
+  #define FLASH_EEPROM_EMULATION
-#define FLASH_EEPROM_EMULATION
+#endif
 
 #define SDSS                              SS_PIN
 

Marlin/src/pins/stm32f1/pins_MKS_ROBIN_MINI.h

@@ -38,11 +38,13 @@
 //
 #define DISABLE_DEBUG
 
-#define FLASH_EEPROM_EMULATION
+#if EITHER(NO_EEPROM_SELECTED, FLASH_EEPROM_EMULATION)
-// 2K in a AT24C16N
+  #define FLASH_EEPROM_EMULATION
-#define EEPROM_PAGE_SIZE     (0x800U) // 2KB
+  // 2K in a AT24C16N
-#define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
+  #define EEPROM_PAGE_SIZE     (0x800U) // 2KB
-#define E2END (EEPROM_PAGE_SIZE - 1)
+  #define EEPROM_START_ADDRESS (0x8000000UL + (STM32_FLASH_SIZE) * 1024UL - (EEPROM_PAGE_SIZE) * 2UL)
+  #define E2END (EEPROM_PAGE_SIZE - 1)
+#endif
 
 //
 // Note: MKS Robin mini board is using SPI2 interface.

Marlin/src/pins/stm32f1/pins_MKS_ROBIN_NANO.h

@@ -41,8 +41,10 @@
 //
 // EEPROM
 //
-//#define FLASH_EEPROM_EMULATION
+#if NO_EEPROM_SELECTED
-#define SDCARD_EEPROM_EMULATION
+  //#define FLASH_EEPROM_EMULATION
+  #define SDCARD_EEPROM_EMULATION
+#endif
 
 //
 // Limit Switches

Marlin/src/pins/stm32f4/pins_BTT_BTT002_V1_0.h

@@ -30,8 +30,10 @@
 #define BOARD_INFO_NAME "BIGTREE Btt002 1.0"
 
 // Use one of these or SDCard-based Emulation will be used
-//#define SRAM_EEPROM_EMULATION                   // Use BackSRAM-based EEPROM emulation
+#if NO_EEPROM_SELECTED
-#define FLASH_EEPROM_EMULATION                    // Use Flash-based EEPROM emulation
+  //#define SRAM_EEPROM_EMULATION                 // Use BackSRAM-based EEPROM emulation
+  #define FLASH_EEPROM_EMULATION                  // Use Flash-based EEPROM emulation
+#endif
 
 // Ignore temp readings during development.
 //#define BOGUS_TEMPERATURE_GRACE_PERIOD 2000

Marlin/src/pins/stm32f4/pins_BTT_GTR_V1_0.h

@@ -32,9 +32,11 @@
 #define BOARD_INFO_NAME "BIGTREE GTR 1.0"
 
 // Use one of these or SDCard-based Emulation will be used
-//#define I2C_EEPROM
+#if NO_EEPROM_SELECTED
-//#define SRAM_EEPROM_EMULATION                   // Use BackSRAM-based EEPROM emulation
+  //#define I2C_EEPROM
-//#define FLASH_EEPROM_EMULATION                  // Use Flash-based EEPROM emulation
+  //#define SRAM_EEPROM_EMULATION                 // Use BackSRAM-based EEPROM emulation
+  //#define FLASH_EEPROM_EMULATION                // Use Flash-based EEPROM emulation
+#endif
 
 #define TP                                        // Enable to define servo and probe pins
 
@@ -389,3 +391,5 @@
   //#define DOGLCD_MOSI                     PB15
 
 #endif // HAS_SPI_LCD
+
+#undef TP

Marlin/src/pins/stm32f4/pins_BTT_SKR_PRO_V1_1.h

@@ -30,8 +30,10 @@
 #define BOARD_INFO_NAME "BIGTREE SKR Pro 1.1" // redefined?
 
 // Use one of these or SDCard-based Emulation will be used
-//#define SRAM_EEPROM_EMULATION                   // Use BackSRAM-based EEPROM emulation
+#if NO_EEPROM_SELECTED
-#define FLASH_EEPROM_EMULATION                    // Use Flash-based EEPROM emulation
+  //#define SRAM_EEPROM_EMULATION                 // Use BackSRAM-based EEPROM emulation
+  #define FLASH_EEPROM_EMULATION                  // Use Flash-based EEPROM emulation
+#endif
 
 //
 // Servos

Marlin/src/pins/stm32f4/pins_FYSETC_S6.h

@@ -34,19 +34,21 @@
   #define DEFAULT_MACHINE_NAME BOARD_INFO_NAME
 #endif
 
-// change the prio to 3 , 2 is for software serial
+// Change the priority to 3. Priority 2 is for software serial.
 //#define TEMP_TIMER_IRQ_PRIO 3
 
 //
 // EEPROM Emulation
 //
-#define FLASH_EEPROM_EMULATION
+#if NO_EEPROM_SELECTED
+  #define FLASH_EEPROM_EMULATION
+  //#define SRAM_EEPROM_EMULATION
+  //#define I2C_EEPROM
+#endif
+
 #if ENABLED(FLASH_EEPROM_EMULATION)
   #define FLASH_EEPROM_LEVELING
-#endif
+#elif ENABLED(I2C_EEPROM)
-//#define SRAM_EEPROM_EMULATION
-//#define I2C_EEPROM
-#ifdef I2C_EEPROM
   #undef E2END                                    // Defined in Arduino Core STM32 to be used with EEPROM emulation. This board uses a real EEPROM.
   #define E2END 0xFFF                             // 4KB
 #endif

Marlin/src/pins/stm32f7/pins_REMRAM_V1.h

@@ -28,7 +28,9 @@
 #define BOARD_INFO_NAME      "RemRam v1"
 #define DEFAULT_MACHINE_NAME "RemRam"
 
-#define SRAM_EEPROM_EMULATION                     // Emulate the EEPROM using Backup SRAM
+#if NO_EEPROM_SELECTED
+  #define SRAM_EEPROM_EMULATION                   // Emulate the EEPROM using Backup SRAM
+#endif
 
 #if HOTENDS > 1 || E_STEPPERS > 1
   #error "RemRam supports only one hotend / E-stepper."