document flash library

This commit is contained in:
King Kévin 2016-08-14 19:25:38 +02:00
parent 54d8f82353
commit dade16b86a
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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/>.
*
*/
/** library to read/write internal flash (code)
* @file flash_internal.c
* @author King Kévin <kingkevin@cuvoodoo.info>
* @date 2016
* @note peripherals used: none
*/
/* standard libraries */
#include <stdint.h> // standard integer types
#include <stdlib.h> // general utilities
/* STM32 (including CM3) libraries */
#include <libopencm3/stm32/desig.h> // device signature utilities
#include <libopencm3/stm32/flash.h> // flash utilities
#include "flash_internal.h" // flash storage library API
#include "global.h" // global definitions
/** the flash page size (medium-density devices have 1KiB page size) */
#define PAGE_SIZE 1024
bool flash_internal_read(uint32_t address, uint8_t *buffer, size_t size)
{
// verify it's in the storage area
if (address<STORAGE_START || (address+size)>STORAGE_END) {
return false;
}
if (buffer==NULL || size==0) {
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)
{
// verify it's in the storage area
if (address<STORAGE_START || (address+size)>STORAGE_END) {
return false;
}
if (buffer==NULL || size==0) {
return false;
}
uint8_t page[PAGE_SIZE]; // the complete page to write
flash_unlock(); // unlock flash to be able to write it
// go through memory
while (size) {
uint32_t page_pre = address%PAGE_SIZE; // the beginning data size in the page
address -= page_pre; // go to beginning of the page
storage_read(address, &page[0], page_pre); // copy existing data
if (size>=PAGE_SIZE-page_pre) { // no need to read tailing page data
for (uint16_t i=0; i<PAGE_SIZE-page_pre; i++) { // put buffer in page
page[page_pre+i] = buffer[i];
}
buffer += PAGE_SIZE-page_pre; // adjust remaining buffer
size -= PAGE_SIZE-page_pre; // adjust remaining size
} else { // need read tailing page data
for (uint16_t i=0; i<size; i++) { // put buffer in page
page[page_pre+i] = buffer[i];
}
buffer += size; // adjust remaining buffer
storage_read(address+page_pre+size, &page[page_pre+size], PAGE_SIZE-page_pre-size); // read tailing page data
size = 0; // adjust remaining size
}
// write page
flash_erase_page(address); // 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(address+i*2, *((uint16_t*)page+i));
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+i)!=*((uint16_t*)page+i)) { // verify the programmed data is right
flash_lock(); // lock back flash to protect it
return false;
}
}
address += PAGE_SIZE; // go to next page
}
flash_lock(); // lock back flash to protect it
return true;
}

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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/>.
*
*/
/** library to read/write internal flash (API)
* @file flash_internal.h
* @author King Kévin <kingkevin@cuvoodoo.info>
* @date 2016
* @note peripherals used: none
*/
#pragma once
#include <libopencm3/stm32/desig.h> // device signature utilities
/** how much data (in bytes) should we be able to store (be sure it's available and does not overlap the firmware) */
#define STORAGE_SIZE 2048
/** the end of the flash area where to store data */
#define STORAGE_END FLASH_BASE+DESIG_FLASH_SIZE
/** the start of the flash area where to store data (be sure it's after the firmware data) */
#define STORAGE_START STORAGE_END-STORAGE_SIZE
/** read data from internal flash
* @param[in] address start address of the data to read
* @param[out] buffer where to store the read data
* @param[in] size how much data to read, in bytes
* @return if read succeeded
*/
bool flash_internal_read(uint32_t address, uint8_t *buffer, size_t size);
/** write data to internal flash
* @param[in] address start address where to write data to
* @param[in] buffer data to be written
* @param[in] size how much data to write, in bytes
* @return if write succeeded
*/
bool flash_internal_write(uint32_t address, uint8_t *buffer, size_t size);