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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 MFS_BANK_MAGIC1 0x35A1EC13
#define MFS_BANK_MAGIC2 0x0FE14991
#define MFS_HEADER_MAGIC 0x1AC7002E
#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. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
#if (MFS_CFG_ID_CACHE_SIZE > 0) || defined(__DOXYGEN__)
void mfs_cache_init(MFSDriver *devp) {
(void)devp;
}
mfs_cached_id_t *mfs_cache_find_id(MFSDriver *devp, uint32_t id) {
(void)devp;
(void)id;
return NULL;
}
void mfs_cache_update_id(MFSDriver *devp, uint32_t id) {
(void)devp;
(void)id;
}
void mfs_cache_erase_id(MFSDriver *devp, uint32_t id) {
(void)devp;
(void)id;
}
#endif /* MFS_CFG_ID_CACHE_SIZE > 0 */
/**
* @brief Determines the state of a flash bank.
*
* @param[in] bank the bank identifier
* @param[out] cntp bank counter value, only valid if the bank is not
* in the @p MFS_BANK_GARBAGE or @p MFS_BANK_ERASED
* states.
*
* @return The bank state.
* @retval MFS_BANK_ERASED if the bank is fully erased.
* @retval MFS_BANK_OK if the bank contains valid data.
* @retval MFS_BANK_PARTIAL if the bank contains errors but the data is still
* readable.
* @retval MFS_BANK_GARBAGE if the bank contains unreadable garbage.
*/
static mfs_bank_state_t mfs_get_bank_state(mfs_bank_t bank, uint32_t *cntp) {
return MFS_BANK_OK;
}
/**
* @brief Performs a flash partition mount attempt.
*
* @param[in] devp pointer to the @p MFSDriver object
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_REPAIR_WARNING if the operation has been completed but a
* repair has been performed.
* @retval MFS_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @api
*/
static mfs_error_t mfs_try_mount(MFSDriver *devp) {
mfs_bank_state_t sts0, sts1;
uint32_t cnt0 = 0, cnt1 = 0;
/* Assessing the state of the two banks.*/
sts0 = mfs_get_bank_state(MFS_BANK_0, &cnt0);
sts1 = mfs_get_bank_state(MFS_BANK_1, &cnt1);
/* 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_validate(MFS_BANK_0, 1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
return MFS_NO_ERROR;
case PAIR(MFS_BANK_ERASED, MFS_BANK_OK):
/* Normal situation, bank one is used.*/
RET_ON_ERROR(mfs_mount(MFS_BANK_1));
return MFS_NO_ERROR;
case PAIR(MFS_BANK_ERASED, MFS_BANK_PARTIAL):
/* Bank zero is erased, bank one has problems.*/
RET_ON_ERROR(mfs_copy_bank(MFS_BANK_1, MFS_BANK_0));
RET_ON_ERROR(mfs_validate(MFS_BANK_0, cnt1 + 1));
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
return MFS_REPAIR_WARNING;
case PAIR(MFS_BANK_ERASED, MFS_BANK_GARBAGE):
/* Bank zero is erased, bank one is not readable.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_1));
RET_ON_ERROR(mfs_validate(MFS_BANK_0, 1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
return MFS_REPAIR_WARNING;
case PAIR(MFS_BANK_OK, MFS_BANK_ERASED):
/* Normal situation, bank zero is used.*/
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
return MFS_NO_ERROR;
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(MFS_BANK_1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
}
else {
/* Bank 1 is newer.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_0));
RET_ON_ERROR(mfs_mount(MFS_BANK_1));
}
return MFS_REPAIR_WARNING;
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(MFS_BANK_1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
}
else {
/* Partial bank one is more recent than the normal bank zero.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_0));
RET_ON_ERROR(mfs_copy_bank(MFS_BANK_1, MFS_BANK_0));
RET_ON_ERROR(mfs_validate(MFS_BANK_0, cnt1 + 1));
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
}
return MFS_REPAIR_WARNING;
case PAIR(MFS_BANK_OK, MFS_BANK_GARBAGE):
/* Bank zero is normal, bank one is unreadable.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
return MFS_REPAIR_WARNING;
case PAIR(MFS_BANK_PARTIAL, MFS_BANK_ERASED):
/* Bank zero has problems, bank one is erased.*/
RET_ON_ERROR(mfs_copy_bank(MFS_BANK_0, MFS_BANK_1));
RET_ON_ERROR(mfs_validate(MFS_BANK_1, cnt0 + 1));
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_0));
RET_ON_ERROR(mfs_mount(MFS_BANK_1));
return MFS_REPAIR_WARNING;
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(MFS_BANK_0));
RET_ON_ERROR(mfs_mount(MFS_BANK_1));
}
else {
/* Partial bank zero is more recent than the normal bank one.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_1));
RET_ON_ERROR(mfs_copy_bank(MFS_BANK_0, MFS_BANK_1));
RET_ON_ERROR(mfs_validate(MFS_BANK_1, cnt0 + 1));
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_0));
RET_ON_ERROR(mfs_mount(MFS_BANK_1));
}
return MFS_REPAIR_WARNING;
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(MFS_BANK_1));
RET_ON_ERROR(mfs_copy_bank(MFS_BANK_0, MFS_BANK_1));
RET_ON_ERROR(mfs_validate(MFS_BANK_1, cnt0 + 1));
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_0));
RET_ON_ERROR(mfs_mount(MFS_BANK_1));
}
else {
/* Bank one is newer, copying in bank zero and using it.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_0));
RET_ON_ERROR(mfs_copy_bank(MFS_BANK_1, MFS_BANK_0));
RET_ON_ERROR(mfs_validate(MFS_BANK_0, cnt1 + 1));
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
}
return MFS_REPAIR_WARNING;
case PAIR(MFS_BANK_PARTIAL, MFS_BANK_GARBAGE):
/* Bank zero has problems, bank one is unreadable.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_1));
RET_ON_ERROR(mfs_copy_bank(MFS_BANK_0, MFS_BANK_1));
RET_ON_ERROR(mfs_validate(MFS_BANK_1, cnt0 + 1));
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_0));
RET_ON_ERROR(mfs_mount(MFS_BANK_1));
return MFS_REPAIR_WARNING;
case PAIR(MFS_BANK_GARBAGE, MFS_BANK_ERASED):
/* Bank zero is unreadable, bank one is erased.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_1));
RET_ON_ERROR(mfs_validate(MFS_BANK_0, 1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
return MFS_REPAIR_WARNING;
case PAIR(MFS_BANK_GARBAGE, MFS_BANK_OK):
/* Bank zero is unreadable, bank one is normal.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_0));
RET_ON_ERROR(mfs_mount(MFS_BANK_1));
return MFS_REPAIR_WARNING;
case PAIR(MFS_BANK_GARBAGE, MFS_BANK_PARTIAL):
/* Bank zero is unreadable, bank one has problems.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_0));
RET_ON_ERROR(mfs_copy_bank(MFS_BANK_1, MFS_BANK_0));
RET_ON_ERROR(mfs_validate(MFS_BANK_0, cnt0 + 1));
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
return MFS_REPAIR_WARNING;
case PAIR(MFS_BANK_GARBAGE, MFS_BANK_GARBAGE):
/* Both banks are unreadable, reinitializing.*/
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_0));
RET_ON_ERROR(mfs_bank_erase(MFS_BANK_1));
RET_ON_ERROR(mfs_validate(MFS_BANK_0, 1));
RET_ON_ERROR(mfs_mount(MFS_BANK_0));
return MFS_REPAIR_WARNING;
default:
osalSysHalt("internal error");
}
/* Never reached.*/
return MFS_INTERNAL_ERROR;
}
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Initializes an instance.
*
* @param[out] devp pointer to the @p MFSDriver object
*
* @init
*/
void mfsObjectInit(MFSDriver *devp) {
osalDbgCheck(devp != NULL);
devp->state = MFS_STOP;
devp->config = NULL;
}
/**
* @brief Configures and activates a MFS driver.
*
* @param[in] devp pointer to the @p MFSDriver object
* @param[in] config pointer to the configuration
*
* @api
*/
void mfsStart(MFSDriver *devp, const MFSConfig *config) {
osalDbgCheck((devp != NULL) && (config != NULL));
osalDbgAssert(devp->state != MFS_UNINIT, "invalid state");
if (devp->state == MFS_STOP) {
devp->config = config;
devp->state = MFS_READY;
}
}
/**
* @brief Deactivates a MFS driver.
*
* @param[in] devp pointer to the @p MFSDriver object
*
* @api
*/
void mfsStop(MFSDriver *devp) {
osalDbgCheck(devp != NULL);
osalDbgAssert(devp->state != MFS_UNINIT, "invalid state");
if (devp->state != MFS_STOP) {
devp->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] devp pointer to the @p MFSDriver object
* @return The operation status.
* @retval MFS_NO_ERROR if the operation has been successfully completed.
* @retval MFS_REPAIR_WARNING if the operation has been completed but a
* repair has been performed.
* @retval MFS_FLASH_FAILURE if the flash memory is unusable because HW
* failures.
*
* @api
*/
mfs_error_t mfsMount(MFSDriver *devp) {
unsigned i;
/* Attempting to mount the managed partition.*/
for (i = 0; i < MFS_MAX_REPAIR_ATTEMPTS; i++) {
mfs_error_t err;
err = mfs_try_mount(devp);
if (!MFS_IS_ERROR(err))
return err;
}
return MFS_FLASH_FAILURE;
}
/**
* @brief Unmounts a manage flash storage.
*/
mfs_error_t mfsUnmount(MFSDriver *devp) {
(void)devp;
return MFS_NO_ERROR;
}
/**
* @brief Retrieves and reads a data record.
*
* @param[in] devp pointer to the @p MFSDriver object
* @param[in] id record numeric identifier
* @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[in] buffer pointer to a buffer for record data
*
* @api
*/
mfs_error_t mfsReadRecord(MFSDriver *devp, uint32_t id,
uint32_t *np, uint8_t *buffer) {
(void)devp;
(void)id;
(void)np;
(void)buffer;
return MFS_NO_ERROR;
}
/**
* @brief Creates or updates a data record.
*
* @param[in] devp pointer to the @p MFSDriver object
* @param[in] id record numeric identifier
* @param[in] n size of data to be written, it cannot be zero
* @param[in] buffer pointer to a buffer for record data
*
* @api
*/
mfs_error_t mfsUpdateRecord(MFSDriver *devp, uint32_t id,
uint32_t n, const uint8_t *buffer) {
(void)devp;
(void)id;
(void)n;
(void)buffer;
return MFS_NO_ERROR;
}
/**
* @brief Erases a data record.
*
* @param[in] devp pointer to the @p MFSDriver object
* @param[in] id record numeric identifier
*
* @api
*/
mfs_error_t mfsEraseRecord(MFSDriver *devp, uint32_t id) {
(void)devp;
(void)id;
return MFS_NO_ERROR;
}
/** @} */
|