/* * This software is experimental and a work in progress. * Under no circumstances should these files be used in relation to any critical system(s). * Use of these files is at your own risk. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR * PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. * * This files are free to use from http://engsta.com/stm32-flash-memory-eeprom-emulator/ by * Artur F. * * Modifications for QMK and STM32F303 by Yiancar * Modifications to add flash wear leveling by Ilya Zhuravlev * Modifications to increase flash density by Don Kjer */ #include #include #include "util.h" #include "debug.h" #include "eeprom_stm32.h" #include "flash_stm32.h" /* * We emulate eeprom by writing a snapshot compacted view of eeprom contents, * followed by a write log of any change since that snapshot: * * === SIMULATED EEPROM CONTENTS === * * ┌─ Compacted ┬ Write Log ─┐ * │............│[BYTE][BYTE]│ * │FFFF....FFFF│[WRD0][WRD1]│ * │FFFFFFFFFFFF│[WORD][NEXT]│ * │....FFFFFFFF│[BYTE][WRD0]│ * ├────────────┼────────────┤ * └──PAGE_BASE │ │ * PAGE_LAST─┴─WRITE_BASE │ * WRITE_LAST ┘ * * Compacted contents are the 1's complement of the actual EEPROM contents. * e.g. An 'FFFF' represents a '0000' value. * * The size of the 'compacted' area is equal to the size of the 'emulated' eeprom. * The size of the compacted-area and write log are configurable, and the combined * size of Compacted + WriteLog is a multiple FEE_PAGE_SIZE, which is MCU dependent. * Simulated Eeprom contents are located at the end of available flash space. * * The following configuration defines can be set: * * FEE_PAGE_COUNT # Total number of pages to use for eeprom simulation (Compact + Write log) * FEE_DENSITY_BYTES # Size of simulated eeprom. (Defaults to half the space allocated by FEE_PAGE_COUNT) * NOTE: The current implementation does not include page swapping, * and FEE_DENSITY_BYTES will consume that amount of RAM as a cached view of actual EEPROM contents. * * The maximum size of FEE_DENSITY_BYTES is currently 16384. The write log size equals * FEE_PAGE_COUNT * FEE_PAGE_SIZE - FEE_DENSITY_BYTES. * The larger the write log, the less frequently the compacted area needs to be rewritten. * * * *** General Algorithm *** * * During initialization: * The contents of the Compacted-flash area are loaded and the 1's complement value * is cached into memory (e.g. 0xFFFF in Flash represents 0x0000 in cache). * Write log entries are processed until a 0xFFFF is reached. * Each log entry updates a byte or word in the cache. * * During reads: * EEPROM contents are given back directly from the cache in memory. * * During writes: * The contents of the cache is updated first. * If the Compacted-flash area corresponding to the write address is unprogrammed, the 1's complement of the value is written directly into Compacted-flash * Otherwise: * If the write log is full, erase both the Compacted-flash area and the Write log, then write cached contents to the Compacted-flash area. * Otherwise a Write log entry is constructed and appended to the next free position in the Write log. * * * *** Write Log Structure *** * * Write log entries allow for optimized byte writes to addresses below 128. Writing 0 or 1 words are also optimized when word-aligned. * * === WRITE LOG ENTRY FORMATS === * * ╔═══ Byte-Entry ══╗ * ║0XXXXXXX║YYYYYYYY║ * ║ └──┬──┘║└──┬───┘║ * ║ Address║ Value ║ * ╚════════╩════════╝ * 0 <= Address < 0x80 (128) * * ╔ Word-Encoded 0 ╗ * ║100XXXXXXXXXXXXX║ * ║ │└─────┬─────┘║ * ║ │Address >> 1 ║ * ║ └── Value: 0 ║ * ╚════════════════╝ * 0 <= Address <= 0x3FFE (16382) * * ╔ Word-Encoded 1 ╗ * ║101XXXXXXXXXXXXX║ * ║ │└─────┬─────┘║ * ║ │Address >> 1 ║ * ║ └── Value: 1 ║ * ╚════════════════╝ * 0 <= Address <= 0x3FFE (16382) * * ╔═══ Reserved ═══╗ * ║110XXXXXXXXXXXXX║ * ╚════════════════╝ * * ╔═══════════ Word-Next ═══════════╗ * ║111XXXXXXXXXXXXX║YYYYYYYYYYYYYYYY║ * ║ └─────┬─────┘║└───────┬──────┘║ * ║(Address-128)>>1║ ~Value ║ * ╚════════════════╩════════════════╝ * ( 0 <= Address < 0x0080 (128): Reserved) * 0x80 <= Address <= 0x3FFE (16382) * * Write Log entry ranges: * 0x0000 ... 0x7FFF - Byte-Entry; address is (Entry & 0x7F00) >> 4; value is (Entry & 0xFF) * 0x8000 ... 0x9FFF - Word-Encoded 0; address is (Entry & 0x1FFF) << 1; value is 0 * 0xA000 ... 0xBFFF - Word-Encoded 1; address is (Entry & 0x1FFF) << 1; value is 1 * 0xC000 ... 0xDFFF - Reserved * 0xE000 ... 0xFFBF - Word-Next; address is (Entry & 0x1FFF) << 1 + 0x80; value is ~(Next_Entry) * 0xFFC0 ... 0xFFFE - Reserved * 0xFFFF - Unprogrammed * */ #include "eeprom_stm32_defs.h" /* These bits are used for optimizing encoding of bytes, 0 and 1 */ #define FEE_WORD_ENCODING 0x8000 #define FEE_VALUE_NEXT 0x6000 #define FEE_VALUE_RESERVED 0x4000 #define FEE_VALUE_ENCODED 0x2000 #define FEE_BYTE_RANGE 0x80 /* Flash word value after erase */ #define FEE_EMPTY_WORD ((uint16_t)0xFFFF) #if !defined(FEE_PAGE_SIZE) || !defined(FEE_PAGE_COUNT) || !defined(FEE_MCU_FLASH_SIZE) || !defined(FEE_PAGE_BASE_ADDRESS) # error "not implemented." #endif /* In-memory contents of emulated eeprom for faster access */ /* *TODO: Implement page swapping */ static uint16_t WordBuf[FEE_DENSITY_BYTES / 2]; static uint8_t *DataBuf = (uint8_t *)WordBuf; /* Pointer to the first available slot within the write log */ static uint16_t *empty_slot; // #define DEBUG_EEPROM_OUTPUT /* * Debug print utils */ #if defined(DEBUG_EEPROM_OUTPUT) # define debug_eeprom debug_enable # define eeprom_println(s) println(s) # define eeprom_printf(fmt, ...) xprintf(fmt, ##__VA_ARGS__); #else /* NO_DEBUG */ # define debug_eeprom false # define eeprom_println(s) # define eeprom_printf(fmt, ...) #endif /* NO_DEBUG */ void print_eeprom(void) { #ifndef NO_DEBUG int empty_rows = 0; for (uint16_t i = 0; i < FEE_DENSITY_BYTES; i++) { if (i % 16 == 0) { if (i >= FEE_DENSITY_BYTES - 16) { /* Make sure we display the last row */ empty_rows = 0; } /* Check if this row is uninitialized */ ++empty_rows; for (uint16_t j = 0; j < 16; j++) { if (DataBuf[i + j]) { empty_rows = 0; break; } } if (empty_rows > 1) { /* Repeat empty row */ if (empty_rows == 2) { /* Only display the first repeat empty row */ println("*"); } i += 15; continue; } xprintf("%04x", i); } if (i % 8 == 0) print(" "); xprintf(" %02x", DataBuf[i]); if ((i + 1) % 16 == 0) { println(""); } } #endif } uint16_t EEPROM_Init(void) { /* Load emulated eeprom contents from compacted flash into memory */ uint16_t *src = (uint16_t *)FEE_COMPACTED_BASE_ADDRESS; uint16_t *dest = (uint16_t *)DataBuf; for (; src < (uint16_t *)FEE_COMPACTED_LAST_ADDRESS; ++src, ++dest) { *dest = ~*src; } if (debug_eeprom) { println("EEPROM_Init Compacted Pages:"); print_eeprom(); println("EEPROM_Init Write Log:"); } /* Replay write log */ uint16_t *log_addr; for (log_addr = (uint16_t *)FEE_WRITE_LOG_BASE_ADDRESS; log_addr < (uint16_t *)FEE_WRITE_LOG_LAST_ADDRESS; ++log_addr) { uint16_t address = *log_addr; if (address == FEE_EMPTY_WORD) { break; } /* Check for lowest 128-bytes optimization */ if (!(address & FEE_WORD_ENCODING)) { uint8_t bvalue = (uint8_t)address; address >>= 8; DataBuf[address] = bvalue; eeprom_printf("DataBuf[0x%02x] = 0x%02x;\n", address, bvalue); } else { uint16_t wvalue; /* Check if value is in next word */ if ((address & FEE_VALUE_NEXT) == FEE_VALUE_NEXT) { /* Read value from next word */ if (++log_addr >= (uint16_t *)FEE_WRITE_LOG_LAST_ADDRESS) { break; } wvalue = ~*log_addr; if (!wvalue) { eeprom_printf("Incomplete write at log_addr: 0x%04x;\n", (uint32_t)log_addr); /* Possibly incomplete write. Ignore and continue */ continue; } address &= 0x1FFF; address <<= 1; /* Writes to addresses less than 128 are byte log entries */ address += FEE_BYTE_RANGE; } else { /* Reserved for future use */ if (address & FEE_VALUE_RESERVED) { eeprom_printf("Reserved encoded value at log_addr: 0x%04x;\n", (uint32_t)log_addr); continue; } /* Optimization for 0 or 1 values. */ wvalue = (address & FEE_VALUE_ENCODED) >> 13; address &= 0x1FFF; address <<= 1; } if (address < FEE_DENSITY_BYTES) { eeprom_printf("DataBuf[0x%04x] = 0x%04x;\n", address, wvalue); *(uint16_t *)(&DataBuf[address]) = wvalue; } else { eeprom_printf("DataBuf[0x%04x] cannot be set to 0x%04x [BAD ADDRESS]\n", address, wvalue); } } } empty_slot = log_addr; if (debug_eeprom) { println("EEPROM_Init Final DataBuf:"); print_eeprom(); } return FEE_DENSITY_BYTES; } /* Clear flash contents (doesn't touch in-memory DataBuf) */ static void eeprom_clear(void) { FLASH_Unlock(); for (uint16_t page_num = 0; page_num < FEE_PAGE_COUNT; ++page_num) { eeprom_printf("FLASH_ErasePage(0x%04x)\n", (uint32_t)(FEE_PAGE_BASE_ADDRESS + (page_num * FEE_PAGE_SIZE))); FLASH_ErasePage(FEE_PAGE_BASE_ADDRESS + (page_num * FEE_PAGE_SIZE)); } FLASH_Lock(); empty_slot = (uint16_t *)FEE_WRITE_LOG_BASE_ADDRESS; eeprom_printf("eeprom_clear empty_slot: 0x%08x\n", (uint32_t)empty_slot); } /* Erase emulated eeprom */ void EEPROM_Erase(void) { eeprom_println("EEPROM_Erase"); /* Erase compacted pages and write log */ eeprom_clear(); /* re-initialize to reset DataBuf */ EEPROM_Init(); } /* Compact write log */ static uint8_t eeprom_compact(void) { /* Erase compacted pages and write log */ eeprom_clear(); FLASH_Unlock(); FLASH_Status final_status = FLASH_COMPLETE; /* Write emulated eeprom contents from memory to compacted flash */ uint16_t *src = (uint16_t *)DataBuf; uintptr_t dest = FEE_COMPACTED_BASE_ADDRESS; uint16_t value; for (; dest < FEE_COMPACTED_LAST_ADDRESS; ++src, dest += 2) { value = *src; if (value) { eeprom_printf("FLASH_ProgramHalfWord(0x%04x, 0x%04x)\n", (uint32_t)dest, ~value); FLASH_Status status = FLASH_ProgramHalfWord(dest, ~value); if (status != FLASH_COMPLETE) final_status = status; } } FLASH_Lock(); if (debug_eeprom) { println("eeprom_compacted:"); print_eeprom(); } return final_status; } static uint8_t eeprom_write_direct_entry(uint16_t Address) { /* Check if we can just write this directly to the compacted flash area */ uintptr_t directAddress = FEE_COMPACTED_BASE_ADDRESS + (Address & 0xFFFE); if (*(uint16_t *)directAddress == FEE_EMPTY_WORD) { /* Write the value directly to the compacted area without a log entry */ uint16_t value = ~*(uint16_t *)(&DataBuf[Address & 0xFFFE]); /* Early exit if a write isn't needed */ if (value == FEE_EMPTY_WORD) return FLASH_COMPLETE; FLASH_Unlock(); eeprom_printf("FLASH_ProgramHalfWord(0x%08x, 0x%04x) [DIRECT]\n", (uint32_t)directAddress, value); FLASH_Status status = FLASH_ProgramHalfWord(directAddress, value); FLASH_Lock(); return status; } return 0; } static uint8_t eeprom_write_log_word_entry(uint16_t Address) { FLASH_Status final_status = FLASH_COMPLETE; uint16_t value = *(uint16_t *)(&DataBuf[Address]); eeprom_printf("eeprom_write_log_word_entry(0x%04x): 0x%04x\n", Address, value); /* MSB signifies the lowest 128-byte optimization is not in effect */ uint16_t encoding = FEE_WORD_ENCODING; uint8_t entry_size; if (value <= 1) { encoding |= value << 13; entry_size = 2; } else { encoding |= FEE_VALUE_NEXT; entry_size = 4; /* Writes to addresses less than 128 are byte log entries */ Address -= FEE_BYTE_RANGE; } /* if we can't find an empty spot, we must compact emulated eeprom */ if (empty_slot > (uint16_t *)(FEE_WRITE_LOG_LAST_ADDRESS - entry_size)) { /* compact the write log into the compacted flash area */ return eeprom_compact(); } /* Word log writes should be word-aligned. Take back a bit */ Address >>= 1; Address |= encoding; /* ok we found a place let's write our data */ FLASH_Unlock(); /* address */ eeprom_printf("FLASH_ProgramHalfWord(0x%08x, 0x%04x)\n", (uint32_t)empty_slot, Address); final_status = FLASH_ProgramHalfWord((uintptr_t)empty_slot++, Address); /* value */ if (encoding == (FEE_WORD_ENCODING | FEE_VALUE_NEXT)) { eeprom_printf("FLASH_ProgramHalfWord(0x%08x, 0x%04x)\n", (uint32_t)empty_slot, ~value); FLASH_Status status = FLASH_ProgramHalfWord((uintptr_t)empty_slot++, ~value); if (status != FLASH_COMPLETE) final_status = status; } FLASH_Lock(); return final_status; } static uint8_t eeprom_write_log_byte_entry(uint16_t Address) { eeprom_printf("eeprom_write_log_byte_entry(0x%04x): 0x%02x\n", Address, DataBuf[Address]); /* if couldn't find an empty spot, we must compact emulated eeprom */ if (empty_slot >= (uint16_t *)FEE_WRITE_LOG_LAST_ADDRESS) { /* compact the write log into the compacted flash area */ return eeprom_compact(); } /* ok we found a place let's write our data */ FLASH_Unlock(); /* Pack address and value into the same word */ uint16_t value = (Address << 8) | DataBuf[Address]; /* write to flash */ eeprom_printf("FLASH_ProgramHalfWord(0x%08x, 0x%04x)\n", (uint32_t)empty_slot, value); FLASH_Status status = FLASH_ProgramHalfWord((uintptr_t)empty_slot++, value); FLASH_Lock(); return status; } uint8_t EEPROM_WriteDataByte(uint16_t Address, uint8_t DataByte) { /* if the address is out-of-bounds, do nothing */ if (Address >= FEE_DENSITY_BYTES) { eeprom_printf("EEPROM_WriteDataByte(0x%04x, 0x%02x) [BAD ADDRESS]\n", Address, DataByte); return FLASH_BAD_ADDRESS; } /* if the value is the same, don't bother writing it */ if (DataBuf[Address] == DataByte) { eeprom_printf("EEPROM_WriteDataByte(0x%04x, 0x%02x) [SKIP SAME]\n", Address, DataByte); return 0; } /* keep DataBuf cache in sync */ DataBuf[Address] = DataByte; eeprom_printf("EEPROM_WriteDataByte DataBuf[0x%04x] = 0x%02x\n", Address, DataBuf[Address]); /* perform the write into flash memory */ /* First, attempt to write directly into the compacted flash area */ FLASH_Status status = eeprom_write_direct_entry(Address); if (!status) { /* Otherwise append to the write log */ if (Address < FEE_BYTE_RANGE) { status = eeprom_write_log_byte_entry(Address); } else { status = eeprom_write_log_word_entry(Address & 0xFFFE); } } if (status != 0 && status != FLASH_COMPLETE) { eeprom_printf("EEPROM_WriteDataByte [STATUS == %d]\n", status); } return status; } uint8_t EEPROM_WriteDataWord(uint16_t Address, uint16_t DataWord) { /* if the address is out-of-bounds, do nothing */ if (Address >= FEE_DENSITY_BYTES) { eeprom_printf("EEPROM_WriteDataWord(0x%04x, 0x%04x) [BAD ADDRESS]\n", Address, DataWord); return FLASH_BAD_ADDRESS; } /* Check for word alignment */ FLASH_Status final_status = FLASH_COMPLETE; if (Address % 2) { final_status = EEPROM_WriteDataByte(Address, DataWord); FLASH_Status status = EEPROM_WriteDataByte(Address + 1, DataWord >> 8); if (status != FLASH_COMPLETE) final_status = status; if (final_status != 0 && final_status != FLASH_COMPLETE) { eeprom_printf("EEPROM_WriteDataWord [STATUS == %d]\n", final_status); } return final_status; } /* if the value is the same, don't bother writing it */ uint16_t oldValue = *(uint16_t *)(&DataBuf[Address]); if (oldValue == DataWord) { eeprom_printf("EEPROM_WriteDataWord(0x%04x, 0x%04x) [SKIP SAME]\n", Address, DataWord); return 0; } /* keep DataBuf cache in sync */ *(uint16_t *)(&DataBuf[Address]) = DataWord; eeprom_printf("EEPROM_WriteDataWord DataBuf[0x%04x] = 0x%04x\n", Address, *(uint16_t *)(&DataBuf[Address])); /* perform the write into flash memory */ /* First, attempt to write directly into the compacted flash area */ final_status = eeprom_write_direct_entry(Address); if (!final_status) { /* Otherwise append to the write log */ /* Check if we need to fall back to byte write */ if (Address < FEE_BYTE_RANGE) { final_status = FLASH_COMPLETE; /* Only write a byte if it has changed */ if ((uint8_t)oldValue != (uint8_t)DataWord) { final_status = eeprom_write_log_byte_entry(Address); } FLASH_Status status = FLASH_COMPLETE; /* Only write a byte if it has changed */ if ((oldValue >> 8) != (DataWord >> 8)) { status = eeprom_write_log_byte_entry(Address + 1); } if (status != FLASH_COMPLETE) final_status = status; } else { final_status = eeprom_write_log_word_entry(Address); } } if (final_status != 0 && final_status != FLASH_COMPLETE) { eeprom_printf("EEPROM_WriteDataWord [STATUS == %d]\n", final_status); } return final_status; } uint8_t EEPROM_ReadDataByte(uint16_t Address) { uint8_t DataByte = 0xFF; if (Address < FEE_DENSITY_BYTES) { DataByte = DataBuf[Address]; } eeprom_printf("EEPROM_ReadDataByte(0x%04x): 0x%02x\n", Address, DataByte); return DataByte; } uint16_t EEPROM_ReadDataWord(uint16_t Address) { uint16_t DataWord = 0xFFFF; if (Address < FEE_DENSITY_BYTES - 1) { /* Check word alignment */ if (Address % 2) { DataWord = DataBuf[Address] | (DataBuf[Address + 1] << 8); } else { DataWord = *(uint16_t *)(&DataBuf[Address]); } } eeprom_printf("EEPROM_ReadDataWord(0x%04x): 0x%04x\n", Address, DataWord); return DataWord; } /***************************************************************************** * Bind to eeprom_driver.c *******************************************************************************/ void eeprom_driver_init(void) { EEPROM_Init(); } void eeprom_driver_erase(void) { EEPROM_Erase(); } void eeprom_read_block(void *buf, const void *addr, size_t len) { const uint8_t *src = (const uint8_t *)addr; uint8_t * dest = (uint8_t *)buf; /* Check word alignment */ if (len && (uintptr_t)src % 2) { /* Read the unaligned first byte */ *dest++ = EEPROM_ReadDataByte((const uintptr_t)src++); --len; } uint16_t value; bool aligned = ((uintptr_t)dest % 2 == 0); while (len > 1) { value = EEPROM_ReadDataWord((const uintptr_t)((uint16_t *)src)); if (aligned) { *(uint16_t *)dest = value; dest += 2; } else { *dest++ = value; *dest++ = value >> 8; } src += 2; len -= 2; } if (len) { *dest = EEPROM_ReadDataByte((const uintptr_t)src); } } void eeprom_write_block(const void *buf, void *addr, size_t len) { uint8_t * dest = (uint8_t *)addr; const uint8_t *src = (const uint8_t *)buf; /* Check word alignment */ if (len && (uintptr_t)dest % 2) { /* Write the unaligned first byte */ EEPROM_WriteDataByte((uintptr_t)dest++, *src++); --len; } uint16_t value; bool aligned = ((uintptr_t)src % 2 == 0); while (len > 1) { if (aligned) { value = *(uint16_t *)src; } else { value = *(uint8_t *)src | (*(uint8_t *)(src + 1) << 8); } EEPROM_WriteDataWord((uintptr_t)((uint16_t *)dest), value); dest += 2; src += 2; len -= 2; } if (len) { EEPROM_WriteDataByte((uintptr_t)dest, *src); } }