flash_internal.c
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/* 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/>.
*
*/
/* standard libraries */
#include <stdint.h> // standard integer types
#include <stdlib.h> // general utilities
/* STM32 (including CM3) libraries */
#include <libopencm3/stm32/flash.h> // flash utilities
#include <libopencm3/stm32/desig.h> // device signature definitions
#include <libopencm3/stm32/dbgmcu.h> // debug definitions
#include "flash_internal.h" // flash storage library API
#include "global.h" // global definitions
static bool flash_internal_range(uint32_t address, size_t size) {
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 enforce 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;
}
}
return true;
}
bool flash_internal_read(uint32_t address, uint8_t *buffer, size_t size)
{
// sanity checks
if (buffer==NULL || size==0) {
return false;
}
if (!flash_internal_range(address, size)) {
return false;
}
// copy data byte per byte (a more efficient way would be to copy words, than the remaining bytes)
for (size_t i=0; i<size; i++) {
buffer[i] = *((uint8_t*)address+i);
}
return true;
}
bool flash_internal_write(uint32_t address, uint8_t *buffer, size_t size)
{
// sanity checks
if (buffer==NULL || size==0 || size%2) {
return false;
}
if (!flash_internal_range(address, size)) {
return false;
}
// verify if it's in the flash area
if (address<FLASH_BASE) {
return false;
} else if ((uint32_t)&__flash_end>=FLASH_BASE && (address+size)>(uint32_t)&__flash_end) {
return false;
} else if ((uint32_t)&__flash_end<FLASH_BASE && (address+size)>(FLASH_BASE+DESIG_FLASH_SIZE*1024)) {
return false;
}
// get page size
uint16_t page_size = 0;
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;
} 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;
} else { // unknown device type (or unreadable type, see errata), deduce page size from flash size
if (DESIG_FLASH_SIZE<256) {
page_size = 1024;
} else {
page_size = 2048;
}
}
flash_unlock(); // unlock flash to be able to write it
while (size) { // write page by page until all data has been written
uint32_t page_start = address-(address%page_size); // get start of the current page
bool erase = false; // verify if the flash to write is erased of if we need to erase the page
for (uint32_t flash=address; flash<(address+size) && flash<(page_start+page_size); flash += 2) { // go through page
if (*(uint16_t*)(flash)!=0xffff) { // is flash not erased
erase = true; // the erase flash
}
}
if (erase) { // make copy of the page to erase and erase it
uint8_t page_data[page_size]; // 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++) {
page_data[page_i++] = *(uint8_t*)(flash);
}
// copy data starting at address
while (size>0 && page_i<page_size) {
page_data[page_i++] = *buffer;
buffer++;
address++;
size--;
}
// copy data after buffer until end of page
while (page_i<page_size) {
page_data[page_i] = *(uint8_t*)(page_start+page_i);
page_i++;
}
flash_erase_page(page_start); // erase current page
if (flash_get_status_flags()!=FLASH_SR_EOP) { // operation went wrong
flash_lock(); // lock back flash to protect it
return false;
}
for (uint16_t i=0; i<page_size/2; i++) { // write whole page
flash_program_half_word(page_start+i*2, *((uint16_t*)(page_data+i*2)));
if (flash_get_status_flags()!=FLASH_SR_EOP) { // operation went wrong
flash_lock(); // lock back flash to protect it
return false;
}
if (*((uint16_t*)(page_data+i*2))!=*((uint16_t*)(page_start+i*2))) { // verify the programmed data is right
flash_lock(); // lock back flash to protect it
return false;
}
}
} else { // simply data until end of page
while (size>0 && address<(page_start+page_size)) {
flash_program_half_word(address, *((uint16_t*)(buffer)));
if (flash_get_status_flags()!=FLASH_SR_EOP) { // operation went wrong
flash_lock(); // lock back flash to protect it
return false;
}
if (*((uint16_t*)address)!=*((uint16_t*)buffer)) { // verify the programmed data is right
flash_lock(); // lock back flash to protect it
return false;
}
buffer += 2;
address += 2;
size -= 2;
}
}
}
flash_lock(); // lock back flash to protect it
return true;
}
flash_internal_range
static bool flash_internal_range(uint32_t address, size_t size)
verify if the data is in the internal flash area
Definition: flash_internal.c:38
global.h
global definitions and methods (API)
flash_internal.h
library to read/write internal flash (API)
__flash_end
char __flash_end
symbol for end of flash
flash_internal_read
bool flash_internal_read(uint32_t address, uint8_t *buffer, size_t size)
read data from internal flash
Definition: flash_internal.c:57
buffer
static uint8_t * buffer
input/output buffer for read/write commands/functions
Definition: onewire_master.c:59
flash_internal_write
bool flash_internal_write(uint32_t address, uint8_t *buffer, size_t size)
write data to internal flash
Definition: flash_internal.c:75