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/*
Managed Flash Storage - Copyright (C) 2016 Giovanni Di Sirio
This file is part of ChibiOS.
ChibiOS 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.
ChibiOS 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/>.
*/
/**
* @file mfs.c
* @brief Managed Flash Storage module code.
* @details This module manages a flash partition as a generic storage where
* arbitrary data records can be created, updated, deleted and
* retrieved.<br>
* A managed partition is composed of two banks of equal size, a
* bank is composed of one or more erasable sectors, a sector is
* divided in writable pages.<br>
* The module handles flash wear leveling and recovery of damaged
* banks (where possible) caused by power loss during operations.
* Both operations are transparent to the user.
*
* @addtogroup mfs
* @{
*/
#include "hal.h"
#include "mfs.h"
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
#define PAIR(a, b) (((unsigned)(a) << 2U) | (unsigned)(b))
/**
* @brief Error check helper.
*/
#define RET_ON_ERROR(err) do { \
mfs_error_t e = (err); \
if (e != MFS_NO_ERROR) { \
return e; \
} \
} while (false)
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local variables and types. */
/*===========================================================================*/
static const uint16_t crc16_table[256] = {
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
};
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
uint16_t crc16(uint16_t crc, const uint8_t *data, size_t n) {
while (n > 0U) {
crc = (crc << 8U) ^ crc16_table[(crc >> 8U) ^ (uint16_t)*data];
data++;
n--;
}
return crc;
}
static void mfs_state_reset(MFSDriver *mfsp) {
unsigned i;
mfsp->current_bank = MFS_BANK_0;
mfsp->current_counter = 0U;
mfsp->next_offset = 0U;
mfsp->used_space = 0U;
for (i = 0; i < MFS_CFG_MAX_RECORDS; i++) {
mfsp->descriptors[i].offset = 0U;
mfsp->descriptors[i].size = 0U;
}
}
static flash_offset_t mfs_flash_get_bank_offset(MFSDriver *mfsp,
mfs_bank_t bank) {
return bank == MFS_BANK_0 ? flashGetSectorOffset(mfsp->config->flashp,
mfsp->config->bank0_start) :
flashGetSectorOffset(mfsp->config->flashp,
mfsp->config->bank1_start);
}
/**
* @brief Flash read.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] offset flash offset
* @param[in] n number of bytes to be read
* @param[out] rp pointer to the data buffer
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @notapi
*/
static mfs_error_t mfs_flash_read(MFSDriver *mfsp, flash_offset_t offset,
size_t n, uint8_t *rp) {
flash_error_t ferr;
ferr = flashRead(mfsp->config->flashp, offset, n, rp);
if (ferr != FLASH_NO_ERROR) {
return MFS_ERR_FLASH_FAILURE;
}
return MFS_NO_ERROR;
}
/**
* @brief Flash write.
* @note If the option @p MFS_CFG_WRITE_VERIFY is enabled then the flash
* is also read back for verification.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] offset flash offset
* @param[in] n number of bytes to be written
* @param[in] wp pointer to the data buffer
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_VERIFY if the verify operation failed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @notapi
*/
static mfs_error_t mfs_flash_write(MFSDriver *mfsp,
flash_offset_t offset,
size_t n,
const uint8_t *wp) {
flash_error_t ferr;
ferr = flashProgram(mfsp->config->flashp, offset, n, wp);
if (ferr != FLASH_NO_ERROR) {
return MFS_ERR_FLASH_FAILURE;
}
/* TODO: Implement verify.*/
return MFS_NO_ERROR;
}
/**
* @brief Flash copy.
* @note If the option @p MFS_CFG_WRITE_VERIFY is enabled then the flash
* is also read back for verification.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] doffset destination flash offset
* @param[in] soffset source flash offset
* @param[in] n number of bytes to be copied
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @notapi
*/
static mfs_error_t mfs_flash_copy(MFSDriver *mfsp,
flash_offset_t doffset,
flash_offset_t soffset,
uint32_t n) {
/* Splitting the operation in smaller operations because the buffer is
small.*/
while (n > 0U) {
/* Data size that can be written in a single program page operation.*/
size_t chunk = (size_t)(((doffset | (MFS_CFG_BUFFER_SIZE - 1U)) + 1U) -
doffset);
if (chunk > n) {
chunk = n;
}
RET_ON_ERROR(mfs_flash_read(mfsp, soffset, chunk, mfsp->buffer.data));
RET_ON_ERROR(mfs_flash_write(mfsp, doffset, chunk, mfsp->buffer.data));
/* Next page.*/
soffset += chunk;
doffset += chunk;
n -= chunk;
}
return MFS_NO_ERROR;
}
/**
* @brief Verifies integrity of a record.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] dhdrp pointer to the header to be checked
* @param[in] offset flash offset of the header to be checked
* @param[in] limit flash limit offset
* @param[out] sts assessed record state
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @notapi
*/
static mfs_error_t mfs_record_check(MFSDriver *mfsp,
mfs_data_header_t *dhdrp,
flash_offset_t offset,
flash_offset_t limit,
mfs_record_state_t *sts) {
unsigned i;
for (i = 0; i < 3; i++) {
if (dhdrp->hdr32[i] != mfsp->config->erased) {
/* Not erased must verify the header.*/
if ((dhdrp->fields.magic != MFS_HEADER_MAGIC) ||
(dhdrp->fields.id < (uint16_t)1) ||
(dhdrp->fields.id > (uint16_t)MFS_CFG_MAX_RECORDS) ||
(dhdrp->fields.size + sizeof (mfs_data_header_t) > limit - offset)) {
*sts = MFS_RECORD_GARBAGE;
return MFS_NO_ERROR;
}
#if MFS_CFG_STRONG_CHECKING == TRUE
{
/* Checking the CRC while reading the record data.*/
(void)mfsp;
}
#else
(void)mfsp;
#endif
}
}
/* It is fully erased.*/
*sts = MFS_RECORD_ERASED;
return MFS_NO_ERROR;
}
/**
* @brief Erases and verifies all sectors belonging to a bank.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] bank bank to be erased
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @notapi
*/
static mfs_error_t mfs_bank_erase(MFSDriver *mfsp, mfs_bank_t bank) {
flash_sector_t sector, end;
if (bank == MFS_BANK_0) {
sector = mfsp->config->bank0_start;
end = mfsp->config->bank0_start + mfsp->config->bank0_sectors;
}
else {
sector = mfsp->config->bank1_start;
end = mfsp->config->bank1_start + mfsp->config->bank1_sectors;
}
while (sector < end) {
flash_error_t ferr;
ferr = flashStartEraseSector(mfsp->config->flashp, sector);
if (ferr != FLASH_NO_ERROR) {
return MFS_ERR_FLASH_FAILURE;
}
ferr = flashWaitErase(mfsp->config->flashp);
if (ferr != FLASH_NO_ERROR) {
return MFS_ERR_FLASH_FAILURE;
}
ferr = flashVerifyErase(mfsp->config->flashp, sector);
if (ferr != FLASH_NO_ERROR) {
return MFS_ERR_FLASH_FAILURE;
}
sector++;
}
return MFS_NO_ERROR;
}
/**
* @brief Erases and verifies all sectors belonging to a bank.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] bank bank to be verified
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_VERIFY if the bank is not erased
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @notapi
*/
static mfs_error_t mfs_bank_verify_erase(MFSDriver *mfsp, mfs_bank_t bank) {
flash_sector_t sector, end;
if (bank == MFS_BANK_0) {
sector = mfsp->config->bank0_start;
end = mfsp->config->bank0_start + mfsp->config->bank0_sectors;
}
else {
sector = mfsp->config->bank1_start;
end = mfsp->config->bank1_start + mfsp->config->bank1_sectors;
}
while (sector < end) {
flash_error_t ferr;
ferr = flashVerifyErase(mfsp->config->flashp, sector);
if (ferr == FLASH_ERROR_VERIFY) {
return MFS_ERR_VERIFY;
}
if (ferr != FLASH_NO_ERROR) {
return MFS_ERR_FLASH_FAILURE;
}
sector++;
}
return MFS_NO_ERROR;
}
/**
* @brief Writes the validation header in a bank.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] bank bank to be validated
* @param[in] cnt value for the flash usage counter
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @notapi
*/
static mfs_error_t mfs_bank_write_header(MFSDriver *mfsp,
mfs_bank_t bank,
uint32_t cnt) {
flash_sector_t sector;
mfs_bank_header_t bhdr;
if (bank == MFS_BANK_0) {
sector = mfsp->config->bank0_start;
}
else {
sector = mfsp->config->bank1_start;
}
bhdr.fields.magic1 = MFS_BANK_MAGIC_1;
bhdr.fields.magic2 = MFS_BANK_MAGIC_2;
bhdr.fields.counter = cnt;
bhdr.fields.reserved1 = (uint16_t)mfsp->config->erased;
bhdr.fields.crc = crc16(0xFFFFU, bhdr.hdr8,
sizeof (mfs_bank_header_t) - sizeof (uint16_t));
return mfs_flash_write(mfsp,
flashGetSectorOffset(mfsp->config->flashp, sector),
sizeof (mfs_bank_header_t),
bhdr.hdr8);
}
/**
* @brief Scans blocks searching for records.
* @note The block integrity is strongly checked.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] bank the bank identifier
* @param[out] statep bank state
* @param[in] foundcb callback to be called for each found record or @p NULL
* @param[in] endcb callback to be called after scanning or @p NULL
*
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*/
static mfs_error_t mfs_bank_scan_records(MFSDriver *mfsp,
mfs_bank_t bank,
mfs_bank_state_t *statep) {
flash_offset_t hdr_offset, start_offset, end_offset;
mfs_record_state_t sts;
bool warning = false;
start_offset = mfs_flash_get_bank_offset(mfsp, bank);
end_offset = start_offset + mfsp->config->bank_size;
/* Scanning records.*/
hdr_offset = start_offset + (flash_offset_t)sizeof(mfs_bank_header_t);
while (hdr_offset < end_offset) {
/* Reading the current record header.*/
RET_ON_ERROR(mfs_flash_read(mfsp, start_offset,
sizeof (mfs_data_header_t),
(void *)&mfsp->buffer.dhdr));
/* Checking header/data integrity.*/
RET_ON_ERROR(mfs_record_check(mfsp, &mfsp->buffer.dhdr,
hdr_offset, end_offset, &sts));
if (sts == MFS_RECORD_ERASED) {
/* Record area fully erased, stopping scan.*/
break;
}
else if (sts == MFS_RECORD_OK) {
/* Record OK.*/
uint32_t size = mfsp->buffer.dhdr.fields.size;
/* Zero-sized records are erase markers.*/
if (size == 0U) {
mfsp->descriptors[mfsp->buffer.dhdr.fields.id - 1].offset = 0U;
mfsp->descriptors[mfsp->buffer.dhdr.fields.id - 1].size = 0U;
}
else {
mfsp->descriptors[mfsp->buffer.dhdr.fields.id - 1].offset = hdr_offset;
mfsp->descriptors[mfsp->buffer.dhdr.fields.id - 1].size = size;
}
}
else if (sts == MFS_RECORD_CRC) {
/* Record payload corrupted, scan can continue because the header
is OK.*/
warning = true;
}
else {
/* Unrecognized header, scanning cannot continue.*/
warning = true;
break;
}
}
if (hdr_offset > end_offset) {
return MFS_ERR_INTERNAL;
}
/* Final.*/
mfsp->next_offset = hdr_offset;
if (warning) {
*statep = MFS_BANK_PARTIAL;
}
else {
*statep = MFS_BANK_OK;
}
return MFS_NO_ERROR;
}
/**
* @brief Selects a bank as current.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] bank bank to be scanned
* @param[out] statep bank state
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @notapi
*/
static mfs_error_t mfs_bank_mount(MFSDriver *mfsp,
mfs_bank_t bank,
mfs_bank_state_t *statep) {
unsigned i;
bool dirty;
mfs_error_t err;
uint16_t crc;
/* Resetting the bank state.*/
mfs_state_reset(mfsp);
/* Worst case is default.*/
*statep = MFS_BANK_GARBAGE;
/* Reading the current bank header.*/
RET_ON_ERROR(mfs_flash_read(mfsp, mfs_flash_get_bank_offset(mfsp, bank),
sizeof (mfs_bank_header_t),
(void *)&mfsp->buffer.bhdr));
/* Checking the special case where the header is erased.*/
dirty = false;
for (i = 0; i < 4; i++) {
if (mfsp->buffer.bhdr.hdr32[i] != mfsp->config->erased) {
dirty = true;
break;
}
}
/* If the header is erased then it could be the whole block erased.*/
if (!dirty) {
err = mfs_bank_verify_erase(mfsp, bank);
if (err == MFS_NO_ERROR) {
*statep = MFS_BANK_ERASED;
}
return MFS_NO_ERROR;
}
/* Checking header fields integrity.*/
if ((mfsp->buffer.bhdr.fields.magic1 != MFS_BANK_MAGIC_1) ||
(mfsp->buffer.bhdr.fields.magic2 != MFS_BANK_MAGIC_2) ||
(mfsp->buffer.bhdr.fields.counter == mfsp->config->erased) ||
(mfsp->buffer.bhdr.fields.reserved1 != (uint16_t)mfsp->config->erased)) {
return MFS_NO_ERROR;
}
/* Verifying header CRC.*/
crc = crc16(0xFFFFU, mfsp->buffer.bhdr.hdr8,
sizeof (mfs_bank_header_t) - sizeof (uint16_t));
if (crc != mfsp->buffer.bhdr.fields.crc) {
return MFS_NO_ERROR;
}
/* Header is OK, storing metadata.*/
mfsp->current_bank = bank;
mfsp->current_counter = mfsp->buffer.bhdr.fields.counter;
/* Scanning for the most recent instance of all records.*/
RET_ON_ERROR(mfs_bank_scan_records(mfsp, bank, statep));
/* Calculating the effective used size.*/
mfsp->used_space = sizeof (mfs_bank_header_t);
for (i = 0; i < MFS_CFG_MAX_RECORDS; i++) {
if (mfsp->descriptors[i].offset != 0U) {
mfsp->used_space += mfsp->descriptors[i].size + sizeof (mfs_data_header_t);
}
}
return MFS_NO_ERROR;
}
/**
* @brief Copies all records from a bank to another.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] sbank source bank
* @param[in] dbank destination bank
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @notapi
*/
static mfs_error_t mfs_bank_copy(MFSDriver *mfsp,
mfs_bank_t sbank,
mfs_bank_t dbank) {
unsigned i;
mfs_bank_state_t sts;
flash_offset_t dest_offset;
RET_ON_ERROR(mfs_bank_mount(mfsp, sbank, &sts));
/* Write address.*/
dest_offset = mfs_flash_get_bank_offset(mfsp, dbank) +
sizeof (mfs_bank_header_t);
/* Copying the most recent record instances only.*/
for (i = 0; i < MFS_CFG_MAX_RECORDS; i++) {
if (mfsp->descriptors[i].offset != 0) {
RET_ON_ERROR(mfs_flash_copy(mfsp, dest_offset,
mfsp->descriptors[i].offset,
mfsp->descriptors[i].size));
dest_offset += mfsp->descriptors[i].size;
}
}
return MFS_NO_ERROR;
}
/**
* @brief Performs a flash partition mount attempt.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_WARN_REPAIR if the operation has been completed but a
* repair has been performed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @api
*/
static mfs_error_t mfs_try_mount(MFSDriver *mfsp) {
mfs_bank_state_t sts, sts0, sts1;
uint32_t cnt0 = 0, cnt1 = 0;
mfs_error_t err;
/* Assessing the state of the two banks by trying to mount them.*/
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts0));
cnt0 = mfsp->current_counter;
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_1, &sts1));
cnt1 = mfsp->current_counter;
/* Handling all possible scenarios, each one requires its own recovery
strategy.*/
switch (PAIR(sts0, sts1)) {
case PAIR(MFS_BANK_ERASED, MFS_BANK_ERASED):
/* Both banks erased, first initialization.*/
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_0, 1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
err = MFS_NO_ERROR;
break;
case PAIR(MFS_BANK_ERASED, MFS_BANK_OK):
/* Normal situation, bank one is used.*/
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_1, &sts)); /* Not necessary.*/
err = MFS_NO_ERROR;
break;
case PAIR(MFS_BANK_ERASED, MFS_BANK_PARTIAL):
/* Bank zero is erased, bank one has problems.*/
RET_ON_ERROR(mfs_bank_copy(mfsp, MFS_BANK_1, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_0, cnt1 + 1));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_ERASED, MFS_BANK_GARBAGE):
/* Bank zero is erased, bank one is not readable.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_0, 1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_OK, MFS_BANK_ERASED):
/* Normal situation, bank zero is used.*/
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
err = MFS_NO_ERROR;
break;
case PAIR(MFS_BANK_OK, MFS_BANK_OK):
/* Both banks appear to be valid but one must be newer, erasing the
older one.*/
if (cnt0 > cnt1) {
/* Bank 0 is newer.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
}
else {
/* Bank 1 is newer.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_1, &sts)); /* Not necessary.*/
}
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_OK, MFS_BANK_PARTIAL):
/* Bank zero is normal, bank one has problems.*/
if (cnt0 > cnt1) {
/* Normal bank zero is more recent than the partial bank one, the
partial bank needs to be erased.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
}
else {
/* Partial bank one is more recent than the normal bank zero.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_copy(mfsp, MFS_BANK_1, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_0, cnt1 + 1));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
}
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_OK, MFS_BANK_GARBAGE):
/* Bank zero is normal, bank one is unreadable.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_PARTIAL, MFS_BANK_ERASED):
/* Bank zero has problems, bank one is erased.*/
RET_ON_ERROR(mfs_bank_copy(mfsp, MFS_BANK_0, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_1, cnt0 + 1));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_1, &sts));
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_PARTIAL, MFS_BANK_OK):
/* Bank zero has problems, bank one is normal.*/
if (cnt1 > cnt0) {
/* Normal bank one is more recent than the partial bank zero, the
partial bank has to be erased.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_1, &sts)); /* Not necessary.*/
}
else {
/* Partial bank zero is more recent than the normal bank one.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_copy(mfsp, MFS_BANK_0, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_1, cnt0 + 1));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_1, &sts));
}
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_PARTIAL, MFS_BANK_PARTIAL):
/* Both banks have problems.*/
if (cnt0 > cnt1) {
/* Bank zero is newer, copying in bank one and using it.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_copy(mfsp, MFS_BANK_0, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_1, cnt0 + 1));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_1, &sts));
}
else {
/* Bank one is newer, copying in bank zero and using it.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_copy(mfsp, MFS_BANK_1, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_0, cnt1 + 1));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
}
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_PARTIAL, MFS_BANK_GARBAGE):
/* Bank zero has problems, bank one is unreadable.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_copy(mfsp, MFS_BANK_0, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_1, cnt0 + 1));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_1, &sts));
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_GARBAGE, MFS_BANK_ERASED):
/* Bank zero is unreadable, bank one is erased.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_0, 1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_GARBAGE, MFS_BANK_OK):
/* Bank zero is unreadable, bank one is normal.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_1, &sts)); /* Not necessary.*/
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_GARBAGE, MFS_BANK_PARTIAL):
/* Bank zero is unreadable, bank one has problems.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_copy(mfsp, MFS_BANK_1, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_0, cnt0 + 1));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
err = MFS_WARN_REPAIR;
break;
case PAIR(MFS_BANK_GARBAGE, MFS_BANK_GARBAGE):
/* Both banks are unreadable, reinitializing.*/
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_0, 1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, &sts));
err = MFS_WARN_REPAIR;
break;
default:
osalSysHalt("internal error");
}
/* If the last mount reported an anomaly then this is an error
because the bank has just been checked/repaired.*/
if (sts != MFS_BANK_OK) {
mfs_state_reset(mfsp);
return MFS_ERR_FLASH_FAILURE;
}
return err;
}
/**
* @brief Enforces a garbage collection.
* @details Storage data is compacted into a single bank.
*
* @param[out] mfsp pointer to the @p MFSDriver object
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @notapi
*/
static mfs_error_t mfs_garbage_collect(MFSDriver *mfsp,
mfs_bank_state_t *statep) {
if (mfsp->current_bank == MFS_BANK_0) {
RET_ON_ERROR(mfs_bank_copy(mfsp, MFS_BANK_0, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_1,
mfsp->current_counter + 1U));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_1, statep));
}
else {
RET_ON_ERROR(mfs_bank_copy(mfsp, MFS_BANK_1, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_write_header(mfsp, MFS_BANK_0,
mfsp->current_counter + 1U));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
RET_ON_ERROR(mfs_bank_mount(mfsp, MFS_BANK_0, statep));
}
return MFS_NO_ERROR;
}
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Initializes an instance.
*
* @param[out] mfsp pointer to the @p MFSDriver object
*
* @init
*/
void mfsObjectInit(MFSDriver *mfsp) {
osalDbgCheck(mfsp != NULL);
mfsp->state = MFS_STOP;
mfsp->config = NULL;
}
/**
* @brief Configures and activates a MFS driver.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] config pointer to the configuration
*
* @api
*/
void mfsStart(MFSDriver *mfsp, const MFSConfig *config) {
osalDbgCheck((mfsp != NULL) && (config != NULL));
osalDbgAssert((mfsp->state == MFS_STOP) || (mfsp->state == MFS_READY),
"invalid state");
if (mfsp->state == MFS_STOP) {
mfsp->config = config;
mfsp->state = MFS_READY;
}
}
/**
* @brief Deactivates a MFS driver.
*
* @param[in] mfsp pointer to the @p MFSDriver object
*
* @api
*/
void mfsStop(MFSDriver *mfsp) {
osalDbgCheck(mfsp != NULL);
osalDbgAssert((mfsp->state == MFS_STOP) || (mfsp->state == MFS_READY),
"invalid state");
if (mfsp->state != MFS_STOP) {
mfsp->config = NULL;
mfs_state_reset(mfsp);
mfsp->state = MFS_STOP;
}
}
/**
* @brief Mounts a managed flash storage.
* @details This functions checks the storage internal state and eventually
* performs the required initialization or repair operations.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_WARN_REPAIR if the operation has been completed but a
* repair has been performed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @api
*/
mfs_error_t mfsMount(MFSDriver *mfsp) {
unsigned i;
osalDbgCheck(mfsp != NULL);
osalDbgAssert(mfsp->state == MFS_READY, "invalid state");
/* Attempting to mount the managed partition.*/
for (i = 0; i < MFS_CFG_MAX_REPAIR_ATTEMPTS; i++) {
mfs_error_t err;
err = mfs_try_mount(mfsp);
if (!MFS_IS_ERROR(err)) {
mfsp->state = MFS_MOUNTED;
return err;
}
}
return MFS_ERR_FLASH_FAILURE;
}
/**
* @brief Unmounts a managed flash storage.
*/
mfs_error_t mfsUnmount(MFSDriver *mfsp) {
osalDbgAssert(mfsp->state == MFS_MOUNTED, "invalid state");
mfs_state_reset(mfsp);
mfsp->state = MFS_READY;
return MFS_NO_ERROR;
}
/**
* @brief Destroys the state of the managed storage by erasing the flash.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @api
*/
mfs_error_t mfsErase(MFSDriver *mfsp) {
osalDbgCheck(mfsp != NULL);
osalDbgAssert(mfsp->state == MFS_READY, "invalid state");
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_0));
RET_ON_ERROR(mfs_bank_erase(mfsp, MFS_BANK_1));
return MFS_NO_ERROR;
}
/**
* @brief Retrieves and reads a data record.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] id record numeric identifier, the valid range is between
* @p 1 and @p MFS_CFG_MAX_RECORDS
* @param[in,out] np on input is the maximum buffer size, on return it is
* the size of the data copied into the buffer
* @param[out] buffer pointer to a buffer for record data
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_NOT_FOUND if the specified id does not exists.
* @retval MFS_ERR_INV_SIZE if the passed buffer is not large enough to
* contain the record data.
* @retval MFS_ERR_CRC if retrieved data has a CRC error.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @api
*/
mfs_error_t mfsReadRecord(MFSDriver *mfsp, uint32_t id,
size_t *np, uint8_t *buffer) {
mfs_error_t err;
osalDbgCheck((mfsp != NULL) && (id >= 1) && (id <= MFS_CFG_MAX_RECORDS) &&
(np != NULL) && (buffer != NULL));
osalDbgAssert(mfsp->state == MFS_MOUNTED, "invalid state");
/* Marking the start of the operation.*/
mfsp->state = MFS_ACTIVE;
/* Checking if the requested record actually exists.*/
if (mfsp->descriptors[id].offset != 0U) {
/* Making sure to not overflow the buffer.*/
if (*np < mfsp->descriptors[id].size) {
err = MFS_ERR_INV_SIZE;
}
else {
/* Data read from flash.*/
*np = mfsp->descriptors[id].size;
err = mfs_flash_read(mfsp,
mfsp->descriptors[id].offset + sizeof (mfs_data_header_t),
*np,
buffer);
/* Checking CRC.*/
if (err == MFS_NO_ERROR) {
uint16_t crc = crc16(0xFFFFU, buffer, *np);
if (crc != mfsp->buffer.dhdr.fields.crc) {
err = MFS_ERR_CRC;
}
}
}
}
else {
err = MFS_ERR_NOT_FOUND;
}
/* Operation over.*/
mfsp->state = MFS_MOUNTED;
return err;
}
/**
* @brief Creates or updates a data record.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] id record numeric identifier, the valid range is between
* @p 1 and @p MFS_CFG_MAX_RECORDS
* @param[in] n size of data to be written, it cannot be zero
* @param[in] buffer pointer to a buffer for record data
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_WARN_GC if the operation triggered a garbage collection.
* @retval MFS_ERR_OUT_OF_MEM if there is not enough flash space for the
* operation.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @api
*/
mfs_error_t mfsWriteRecord(MFSDriver *mfsp, uint32_t id,
size_t n, const uint8_t *buffer) {
flash_offset_t free, required;
mfs_bank_state_t sts;
bool warning = false;
osalDbgCheck((mfsp != NULL) && (id >= 1) && (id <= MFS_CFG_MAX_RECORDS) &&
(n > 0U) && (buffer != NULL));
osalDbgAssert(mfsp->state == MFS_MOUNTED, "invalid state");
/* Marking the start of the operation.*/
mfsp->state = MFS_ACTIVE;
/* If the required space is beyond the available (compacted) block
size then an error is returned.
NOTE: The space for one extra header is reserved in order to allow
for an erase operation after the space has been fully allocated.*/
required = ((flash_offset_t)sizeof (mfs_data_header_t) * 2U) +
(flash_offset_t)n;
if (required > mfsp->config->bank_size - mfsp->used_space) {
return MFS_ERR_OUT_OF_MEM;
}
/* Checking for immediately (not compacted) available space.*/
free = mfsp->config->bank_size - mfsp->next_offset;
if (required > free) {
/* We need to perform a garbage collection, there is enough space
but it has to be freed.*/
warning = true;
RET_ON_ERROR(mfs_garbage_collect(mfsp, &sts));
}
/* Writing the data header without the magic, it will be written last.*/
mfsp->buffer.dhdr.fields.magic = (uint32_t)mfsp->config->erased;
mfsp->buffer.dhdr.fields.id = (uint16_t)id;
mfsp->buffer.dhdr.fields.size = (uint32_t)n;
mfsp->buffer.dhdr.fields.crc = crc16(0xFFFFU, buffer, n);
RET_ON_ERROR(mfs_flash_write(mfsp,
mfsp->next_offset,
sizeof (mfs_data_header_t),
mfsp->buffer.data));
/* Writing the data part.*/
RET_ON_ERROR(mfs_flash_write(mfsp,
mfsp->next_offset + sizeof (mfs_data_header_t),
n,
buffer));
/* Finally writing the magic number, it seals the transaction.*/
mfsp->buffer.dhdr.fields.magic = (uint32_t)MFS_HEADER_MAGIC;
RET_ON_ERROR(mfs_flash_write(mfsp,
mfsp->next_offset,
sizeof (uint32_t),
mfsp->buffer.data));
/* Adjusting bank-related metadata.*/
mfsp->next_offset += sizeof (mfs_data_header_t) + n;
mfsp->used_space -= sizeof (mfs_data_header_t) + n;
/* Operation over.*/
mfsp->state = MFS_MOUNTED;
return warning ? MFS_WARN_GC : MFS_NO_ERROR;
}
/**
* @brief Erases a data record.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @param[in] id record numeric identifier, the valid range is between
* @p 1 and @p MFS_CFG_MAX_RECORDS
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @api
*/
mfs_error_t mfsEraseRecord(MFSDriver *mfsp, uint32_t id) {
osalDbgAssert(mfsp->state == MFS_MOUNTED, "invalid state");
/* Marking the start of the operation.*/
mfsp->state = MFS_ACTIVE;
(void)id;
/* Operation over.*/
mfsp->state = MFS_MOUNTED;
return MFS_NO_ERROR;
}
/**
* @brief Enforces a garbage collection operation.
* @details Garbage collection involves: integrity check, optionally repairs,
* obsolete data removal, data compaction and a flash bank swap.
*
* @param[in] mfsp pointer to the @p MFSDriver object
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_WARN_REPAIR if the operation has been completed but a
* repair has been performed.
* @retval MFS_ERR_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @api
*/
mfs_error_t mfsPerformGarbageCollection(MFSDriver *mfsp) {
mfs_error_t err;
mfs_bank_state_t sts;
osalDbgAssert(mfsp->state == MFS_MOUNTED, "invalid state");
/* Marking the start of the operation.*/
mfsp->state = MFS_ACTIVE;
err = mfs_garbage_collect(mfsp, &sts);
/* Operation over.*/
mfsp->state = MFS_MOUNTED;
return err;
}
/** @} */
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