OpenRTX/platform/mcu/STM32F4xx/drivers/flash.c

94 wiersze
3.0 KiB
C

/***************************************************************************
* Copyright (C) 2021 - 2025 by Federico Amedeo Izzo IU2NUO, *
* Niccolò Izzo IU2KIN *
* Frederik Saraci IU2NRO *
* Silvano Seva IU2KWO *
* *
* 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/> *
***************************************************************************/
#include <stm32f4xx.h>
#include <stddef.h>
#include "flash.h"
/**
* \internal
* Utility function performing unlock of flash erase and write access.
*
* @true on success, false on failure.
*/
static inline bool unlock()
{
// Flash already unlocked
if((FLASH->CR & FLASH_CR_LOCK) == 0)
{
return true;
}
FLASH->KEYR = 0x45670123;
FLASH->KEYR = 0xCDEF89AB;
// Succesful unlock
if((FLASH->CR & FLASH_CR_LOCK) == 0)
{
return true;
}
return false;
}
bool flash_eraseSector(const uint8_t secNum)
{
if(secNum > 11) return false;
if(unlock() == false) return false;
// Flash busy, wait until previous operation finishes
while((FLASH->SR & FLASH_SR_BSY) != 0) ;
FLASH->CR |= FLASH_CR_SER; // Sector erase
FLASH->CR &= ~FLASH_CR_SNB;
FLASH->CR |= (secNum << 3); // Sector number
FLASH->CR |= FLASH_CR_STRT; // Start erase
// Wait until erase ends
while((FLASH->SR & FLASH_SR_BSY) != 0) ;
FLASH->CR &= ~FLASH_CR_SER;
return true;
}
void flash_write(const uint32_t address, const void *data, const size_t len)
{
if(unlock() == false) return;
if((data == NULL) || (len == 0)) return;
// Write data to memory, 8 bit at a time
const uint8_t *buf = ((uint8_t *) data);
uint8_t *mem = ((uint8_t *) address);
for(size_t i = 0; i < len; i++)
{
while((FLASH->SR & FLASH_SR_BSY) != 0) ;
FLASH->CR = FLASH_CR_PG;
*mem = buf[i];
mem++;
while((FLASH->SR & FLASH_SR_BSY) != 0) ;
FLASH->CR &= ~FLASH_CR_PG;
}
}