Use flash memory to emulate EEPROM (#11500)

Use a sector of the LPC flash memory to emulate EEPROM storage, removing the need to have an SD card to store system parameters.

Marlin/src/HAL/HAL_LPC1768/persistent_store_api.h

@@ -0,0 +1,24 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016, 2017 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * 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/>.
+ *
+ */
+#include "../persistent_store_api.h"
+
+//#define FLASH_EEPROM

Marlin/src/HAL/HAL_LPC1768/persistent_store_flash.cpp

@@ -0,0 +1,139 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016, 2017 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * 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 TARGET_LPC1768
+
+/**
+ * Emulate EEPROM storage using Flash Memory
+ *
+ * Use a single 32K flash sector to store EEPROM data. To reduce the
+ * number of erase operations a simple "levelling" scheme is used that
+ * maintains a number of EEPROM "slots" within the larger flash sector.
+ * Each slot is used in turn and the entire sector is only erased when all
+ * slots have been used.
+ *
+ * A simple RAM image is used to hold the EEPROM data during I/O operations
+ * and this is flushed to the next available slot when an update is complete.
+ * If RAM usage becomes an issue we could store this image in one of the two
+ * 16Kb I/O buffers (intended to hold DMA USB and Ethernet data, but currently
+ * unused).
+ */
+#include "../../inc/MarlinConfigPre.h"
+
+#if ENABLED(EEPROM_SETTINGS)
+
+#include "persistent_store_api.h"
+
+#if ENABLED(FLASH_EEPROM)
+
+extern "C" {
+  #include "lpc17xx_iap.h"
+}
+
+#define SECTOR_START(sector)	((sector < 16) ? (sector * 0x1000) : ((sector - 14) * 0x8000))
+#define EEPROM_SECTOR 29
+#define EEPROM_SIZE (E2END+1)
+#define SECTOR_SIZE (32768)
+#define EEPROM_SLOTS (SECTOR_SIZE/EEPROM_SIZE)
+#define EEPROM_ERASE (0xff)
+#define SLOT_ADDRESS(sector, slot) (((uint8_t *)SECTOR_START(sector)) + slot * EEPROM_SIZE)
+
+#if EEPROM_SIZE != 4096
+  #error "EEPROM_SIZE must match flash write size"
+#endif
+
+static uint8_t ram_eeprom[EEPROM_SIZE];
+static bool eeprom_dirty = false;
+static int current_slot = 0;
+
+bool PersistentStore::access_start() {
+  uint32_t first_nblank_loc, first_nblank_val;
+  IAP_STATUS_CODE status;
+
+  // discover which slot we are currently using.
+  __disable_irq();
+  status = BlankCheckSector(EEPROM_SECTOR, EEPROM_SECTOR, &first_nblank_loc, &first_nblank_val);
+  __enable_irq();
+  SERIAL_PROTOCOLLNPAIR("Blank check status: ", status);
+  if (status == CMD_SUCCESS) {
+    // sector is blank so nothing stored yet
+    SERIAL_PROTOCOLLNPGM("FLASH empty");
+    for (int i = 0; i < EEPROM_SIZE; i++) ram_eeprom[i] = EEPROM_ERASE;
+    current_slot = EEPROM_SLOTS;
+  }
+  else {
+    // current slot is the first non blank one
+    current_slot = first_nblank_loc / EEPROM_SIZE;
+    SERIAL_PROTOCOLLNPAIR("Flash slot: ", current_slot);
+    uint8_t *eeprom_data = SLOT_ADDRESS(EEPROM_SECTOR, current_slot);
+    SERIAL_PROTOCOLLNPAIR("Address: ", (int)eeprom_data);
+
+    // load current settings
+    for (int i = 0; i < EEPROM_SIZE; i++) ram_eeprom[i] = eeprom_data[i];
+  }
+  eeprom_dirty = false;
+
+  return true;
+}
+
+bool PersistentStore::access_finish() {
+  if (eeprom_dirty) {
+    IAP_STATUS_CODE status;
+    if (--current_slot < 0) {
+      // all slots have been used, erase everything and start again
+      __disable_irq();
+      PrepareSector(EEPROM_SECTOR, EEPROM_SECTOR);
+      status = EraseSector(EEPROM_SECTOR, EEPROM_SECTOR);
+      __enable_irq();
+      SERIAL_PROTOCOLLNPAIR("Erase status: ", status);
+      current_slot = EEPROM_SLOTS - 1;
+    }
+    SERIAL_PROTOCOLLNPAIR("Writing data to: ", current_slot);
+    __disable_irq();
+    PrepareSector(EEPROM_SECTOR, EEPROM_SECTOR);
+    status = CopyRAM2Flash(SLOT_ADDRESS(EEPROM_SECTOR, current_slot), ram_eeprom, IAP_WRITE_4096);
+    __enable_irq();
+    SERIAL_PROTOCOLLNPAIR("CopyRAM2Flash status: ", status);
+    if (status != CMD_SUCCESS) return false;
+    eeprom_dirty = false;
+  }
+  return true;
+}
+
+bool PersistentStore::write_data(int &pos, const uint8_t *value, uint16_t size, uint16_t *crc) {
+  for (int i = 0; i < size; i++) ram_eeprom[pos + i] = value[i];
+  eeprom_dirty = true;
+  crc16(crc, value, size);
+  pos += size;
+  return false;  // return true for any error
+}
+
+bool PersistentStore::read_data(int &pos, uint8_t* value, uint16_t size, uint16_t *crc, const bool writing/*=true*/) {
+  const uint8_t * const buff = writing ? &value[0] : &ram_eeprom[pos];
+  if (writing) for (int i = 0; i < size; i++) value[i] = ram_eeprom[pos + i];
+  crc16(crc, buff, size);
+  pos += size;
+  return false;  // return true for any error
+}
+
+#endif // FLASH_EEPROM
+#endif // EEPROM_SETTINGS
+#endif // TARGET_LPC1768

Marlin/src/HAL/HAL_LPC1768/persistent_store_sdcard.cpp

@@ -22,11 +22,13 @@
  */
 #ifdef TARGET_LPC1768
 
-#include "../../inc/MarlinConfig.h"
+#include "../../inc/MarlinConfigPre.h"
 
 #if ENABLED(EEPROM_SETTINGS)
 
-#include "../persistent_store_api.h"
+#include "persistent_store_api.h"
+
+#if DISABLED(FLASH_EEPROM)
 
 #include <chanfs/diskio.h>
 #include <chanfs/ff.h>
@@ -73,8 +75,31 @@ bool PersistentStore::access_finish() {
   return true;
 }
 
-// File function return codes for type FRESULT   This goes away soon.   But it is helpful right now to see
+// This extra chit-chat goes away soon, but is helpful for now
-// the different errors the read_data() and write_data() functions are seeing.
+// to see errors that are happening in read_data / write_data
+static void debug_rw(const bool write, int &pos, const uint8_t *value, const size_t size, const FRESULT s, const size_t total=0) {
+  const char * const rw_str = write ? PSTR("write") : PSTR("read");
+  SERIAL_PROTOCOLCHAR(' ');
+  serialprint_PGM(rw_str);
+  SERIAL_PROTOCOLPAIR("_data(", pos);
+  SERIAL_PROTOCOLPAIR(",", (int)value);
+  SERIAL_PROTOCOLPAIR(",", (int)size);
+  SERIAL_PROTOCOLLNPGM(", ...)");
+  if (total) {
+    SERIAL_PROTOCOLPGM(" f_");
+    serialprint_PGM(rw_str);
+    SERIAL_PROTOCOLPAIR("()=", (int)s);
+    SERIAL_PROTOCOLPAIR("\n size=", size);
+    SERIAL_PROTOCOLPGM("\n bytes_");
+    serialprint_PGM(write ? PSTR("written=") : PSTR("read="));
+    SERIAL_PROTOCOLLN(total);
+  }
+  else
+    SERIAL_PROTOCOLLNPAIR(" f_lseek()=", (int)s);
+}
+
+// File function return codes for type FRESULT. This goes away soon, but
+// is helpful right now to see any errors in read_data and write_data.
 //
 //  typedef enum {
 //    FR_OK = 0,               /* (0) Succeeded */
@@ -106,28 +131,18 @@ bool PersistentStore::write_data(int &pos, const uint8_t *value, const size_t si
 
   s = f_lseek(&eeprom_file, pos);
   if (s) {
-   SERIAL_PROTOCOLPAIR(" write_data(", pos);         // This extra chit-chat goes away soon.  But it is helpful
+    debug_rw(true, pos, value, size, s);
-   SERIAL_PROTOCOLPAIR(",", (int)value);            // right now to see errors that are happening in the
-   SERIAL_PROTOCOLPAIR(",", (int)size);             // read_data() and write_data() functions
-   SERIAL_PROTOCOLLNPGM("...)");
-   SERIAL_PROTOCOLLNPAIR(" f_lseek()=", (int)s);
     return s;
   }
 
   s = f_write(&eeprom_file, (void*)value, size, &bytes_written);
   if (s) {
-   SERIAL_PROTOCOLPAIR(" write_data(", pos);         // This extra chit-chat goes away soon.  But it is helpful
+    debug_rw(true, pos, value, size, s, bytes_written);
-   SERIAL_PROTOCOLPAIR(",", (int)value);            // right now to see errors that are happening in the
-   SERIAL_PROTOCOLPAIR(",", size);             // read_data() and write_data() functions
-   SERIAL_PROTOCOLLNPGM("...)");
-   SERIAL_PROTOCOLLNPAIR(" f_write()=", (int)s);
-   SERIAL_PROTOCOLPAIR(" size=", size);
-   SERIAL_PROTOCOLLNPAIR("\n bytes_written=", bytes_written);
     return s;
   }
   crc16(crc, value, size);
-  pos = pos + size;
+  pos += size;
-  return (bytes_written != size);  // return true for any error
+  return bytes_written != size;  // return true for any error
 }
 
 bool PersistentStore::read_data(int &pos, uint8_t* value, const size_t size, uint16_t *crc, const bool writing/*=true*/) {
@@ -137,13 +152,7 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, const size_t size, uin
   s = f_lseek(&eeprom_file, pos);
 
   if (s) {
-   SERIAL_PROTOCOLPAIR(" read_data(", pos);         // This extra chit-chat goes away soon.  But it is helpful
+    debug_rw(false, pos, value, size, s);
-   SERIAL_PROTOCOLCHAR(',');
-   SERIAL_PROTOCOL((int)value);                     // right now to see errors that are happening in the
-   SERIAL_PROTOCOLCHAR(',');
-   SERIAL_PROTOCOL(size);                           // read_data() and write_data() functions
-   SERIAL_PROTOCOLLNPGM("...)");
-   SERIAL_PROTOCOLLNPAIR(" f_lseek()=", (int)s);
     return true;
   }
 
@@ -158,23 +167,16 @@ bool PersistentStore::read_data(int &pos, uint8_t* value, const size_t size, uin
   }
 
   if (s) {
-   SERIAL_PROTOCOLPAIR(" read_data(", pos);         // This extra chit-chat goes away soon.  But it is helpful
+    debug_rw(false, pos, value, size, s, bytes_read);
-   SERIAL_PROTOCOLCHAR(',');
-   SERIAL_PROTOCOL((int)value);                     // right now to see errors that are happening in the
-   SERIAL_PROTOCOLCHAR(',');
-   SERIAL_PROTOCOL(size);                           // read_data() and write_data() functions
-   SERIAL_PROTOCOLLNPGM("...)");
-   SERIAL_PROTOCOLLNPAIR(" f_write()=", (int)s);
-   SERIAL_PROTOCOLPAIR(" size=", size);
-   SERIAL_PROTOCOLLNPAIR("\n bytes_read=",  bytes_read);
     return true;
   }
 
-  pos = pos + size;
+  pos += size;
   return bytes_read != size;  // return true for any error
 }
 
 const size_t PersistentStore::capacity() { return 4096; } // 4KiB of Emulated EEPROM
 
+#endif // !FLASH_EEPROM
 #endif // EEPROM_SETTINGS
 #endif // TARGET_LPC1768

frameworks/CMSIS/LPC1768/system/LPC1768.ld

@@ -1,8 +1,10 @@
 /* Linker script for mbed LPC1768 */
 MEMORY
 {
-  //FLASH (rx) : ORIGIN = 0x00000000, LENGTH = 512K
+  /* Reserve first 16K (4 sectors * 4KB) for bootloader
-  FLASH (rx) : ORIGIN = 16K, LENGTH = (512K - 16K)
+   * Reserve the last 32KB sector for EEPROM emulation
+   */
+  FLASH (rx) : ORIGIN = 16K, LENGTH = (512K - 48K)
   RAM (rwx) : ORIGIN = 0x100000C8, LENGTH = (32K - 0xC8)
 
   USB_RAM(rwx) : ORIGIN = 0x2007C000, LENGTH = 16K