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flash_internal: use common page size and flash end address

This commit is contained in:
King Kévin 2020-02-19 20:58:32 +01:00
parent c30b3ecb48
commit b7e72bba67
1 changed files with 42 additions and 40 deletions
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82
lib/flash_internal.c
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@ -33,11 +33,30 @@
/** number of flash pages, located at the end of flash memory, to use for EEPROM functionality */
static uint16_t flash_internal_eeprom_pages = 0;
/** flash page size */
static uint16_t flash_internal_page = 0;
/** end address of flash */
static uint32_t flash_internal_end = 0;
/** start address of flash memory used for the emulated EEPROM */
static uint32_t flash_internal_eeprom_start = 0;
/** start address of emulated EEPROM */
static uint32_t flash_internal_eeprom_address = 0;
/** find out page size and flash end address */
static void flash_internal_init(void)
{
if (0 == flash_internal_page) {
flash_internal_page_size(); // get page size
}
if (0 == flash_internal_end) {
if ((uint32_t)&__flash_end >= FLASH_BASE) {
flash_internal_end = (uint32_t)&__flash_end;
} else {
flash_internal_end = FLASH_BASE + DESIG_FLASH_SIZE * 1024;
}
}
}
/** verify if the data is in the internal flash area
* @param[in] address start address of the data to read
* @param[in] size how much data to read or write, in bytes
@ -45,20 +64,17 @@ static uint32_t flash_internal_eeprom_address = 0;
*/
static bool flash_internal_range(uint32_t address, size_t size)
{
if (0 == flash_internal_page || 0 == flash_internal_end) {
flash_internal_init();
}
if (address > (UINT32_MAX - size)) { // on integer overflow will occur
return false;
}
if (address < FLASH_BASE) { // start address is before the start of the internal flash
return false;
}
if ((uint32_t)&__flash_end >= FLASH_BASE) { // check if the end for the internal flash is enforced by the linker script
if ((address + size) > (uint32_t)&__flash_end) { // end address is after the end of the enforced internal flash
return false;
}
} else {
if ((address + size) > (FLASH_BASE + DESIG_FLASH_SIZE * 1024)) { // end address is after the end of the advertised flash
return false;
}
if ((address + size) > flash_internal_end) { // end address is after the end of the internal flash
return false;
}
return true;
}
@ -68,26 +84,21 @@ static bool flash_internal_range(uint32_t address, size_t size)
*/
uint16_t flash_internal_page_size(void)
{
static uint16_t page_size = 0; // remember page size
if (page_size) { // we already determined the size
return page_size;
}
if (0 == page_size) { // we don't know the page size yet
if (0 == flash_internal_page) { // we don't know the page size yet
if ((0x410 == (DBGMCU_IDCODE & DBGMCU_IDCODE_DEV_ID_MASK)) || (0x412 == (DBGMCU_IDCODE & DBGMCU_IDCODE_DEV_ID_MASK))) { // low-density (16-32 KB flash) and medium-density (64-128 KB flash) devices have 1 KB flash pages
page_size = 1024;
flash_internal_page = 1024;
} else if ((0x414 == (DBGMCU_IDCODE & DBGMCU_IDCODE_DEV_ID_MASK)) || (0x430 == (DBGMCU_IDCODE & DBGMCU_IDCODE_DEV_ID_MASK)) || (0x418 == (DBGMCU_IDCODE & DBGMCU_IDCODE_DEV_ID_MASK))) { // high-density (256-512 KB flash), XL-density (768-1024 KB flash) devices and connectivity line have 2 KB flash pages
page_size = 2048;
flash_internal_page = 2048;
} else { // unknown device type (or unreadable type, see errata), deduce page size from flash size
if (DESIG_FLASH_SIZE < 256) {
page_size = 1024;
flash_internal_page = 1024;
} else {
page_size = 2048;
flash_internal_page = 2048;
}
}
}
return page_size;
return flash_internal_page;
}
bool flash_internal_read(uint32_t address, uint8_t *buffer, size_t size)
@ -113,33 +124,24 @@ int32_t flash_internal_write(uint32_t address, const uint8_t *buffer, size_t siz
// sanity checks
if (buffer == NULL || size == 0 || size % 2) {
return -1;
}
if (!flash_internal_range(address, size)) {
} else if (address < FLASH_BASE) {
return -2;
}
// verify if it's in the flash area
if (address < FLASH_BASE) {
} else if (!flash_internal_range(address, size)) {
return -3;
} else if ((uint32_t)&__flash_end >= FLASH_BASE && (address + size) > (uint32_t)&__flash_end) {
return -4;
} else if ((uint32_t)&__flash_end < FLASH_BASE && (address + size) > (FLASH_BASE + DESIG_FLASH_SIZE * 1024)) {
return -5;
}
uint16_t page_size = flash_internal_page_size(); // get page size
uint32_t written = 0; // number of bytes written
flash_unlock(); // unlock flash to be able to write it
while (size) { // write page by page until all data has been written
// verify of we need to erase the flash before writing it
uint32_t page_start = address - (address % page_size); // get start of the current page
uint32_t page_start = address - (address % flash_internal_page); // get start of the current page
bool erase = false; // verify if we need to erase the page
bool identical = true; // verify if we actually need to write data, or if the data to be written is the identical to the one already if flash
for (uint32_t i = 0; i < size && (address + i) < (page_start + page_size); i += 2) { // verify if no bit needs to be flipped to 1 again
for (uint32_t i = 0; i < size && (address + i) < (page_start + flash_internal_page); i += 2) { // verify if any word in this page needs to be programmed
if (*(uint16_t*)(buffer + i) != (*(uint16_t*)(address + i))) { // verify if the data to be written is identical to the one already written
identical = false;
// in theory writing flash is only about flipping (individual) bits from 1 (erase state) to 0
// in practice the micro-controller won't allow to flip individual bits if the whole half-word is erased (set to 0xffff)
// in practice the micro-controller will only allow to flip individual bits if the whole half-word is erased (set to 0xffff)
if (*(uint16_t*)(address + i) != 0xffff) { // flash is not erased
erase = true; // we need to erase it for it to be written
break; // no need to check further
@ -148,7 +150,7 @@ int32_t flash_internal_write(uint32_t address, const uint8_t *buffer, size_t siz
}
if (identical) { // no data needs to be changed
// go to end of page, or size
uint32_t remaining = (page_start + page_size) - address;
uint32_t remaining = (page_start + flash_internal_page) - address;
if (remaining > size) {
remaining = size;
}
@ -157,21 +159,21 @@ int32_t flash_internal_write(uint32_t address, const uint8_t *buffer, size_t siz
address += remaining;
size -= remaining;
} else if (erase && preserve) { // erase before
uint8_t page_data[page_size]; // a copy of the complete page before the erase it
uint8_t page_data[flash_internal_page]; // a copy of the complete page before the erase it
uint16_t page_i = 0; // index for page data
// copy page before address
for (uint32_t flash = page_start; flash < address && flash < (page_start + page_size) && page_i < page_size; flash++) {
for (uint32_t flash = page_start; flash < address && flash < (page_start + flash_internal_page) && page_i <flash_internal_page; flash++) {
page_data[page_i++] = *(uint8_t*)(flash);
}
// copy data starting at address
while (size > 0 && page_i < page_size) {
while (size > 0 && page_i < flash_internal_page) {
page_data[page_i++] = *buffer;
buffer++;
address++;
size--;
}
// copy data after buffer until end of page
while (page_i < page_size) {
while (page_i < flash_internal_page) {
page_data[page_i] = *(uint8_t*)(page_start + page_i);
page_i++;
}
@ -180,7 +182,7 @@ int32_t flash_internal_write(uint32_t address, const uint8_t *buffer, size_t siz
flash_lock(); // lock back flash to protect it
return -6;
}
for (uint16_t i = 0; i < page_size; i += 2) { // write whole page
for (uint16_t i = 0; i < flash_internal_page; i += 2) { // write whole page
if (*((uint16_t*)(page_data + i)) != 0xffff) { // after an erase the bits are set to one, no need to program them
flash_program_half_word(page_start + i, *((uint16_t*)(page_data + i)));
if (flash_get_status_flags() != FLASH_SR_EOP) { // operation went wrong
@ -202,7 +204,7 @@ int32_t flash_internal_write(uint32_t address, const uint8_t *buffer, size_t siz
return -9;
}
}
while (size > 0 && address < (page_start + page_size)) {
while (size > 0 && address < (page_start + flash_internal_page)) {
if (*((uint16_t*)(buffer)) != *((uint16_t*)(address)) && *((uint16_t*)(buffer)) != 0xffff) { // only program when data is different and bits need to be set
flash_program_half_word(address, *((uint16_t*)(buffer))); // program the data
if (flash_get_status_flags() != FLASH_SR_EOP) { // operation went wrong