Question
How to store data in flash memory of STM32F401CCU6?
My STM32F401CCU6 has 256K flash memory, and I want to use it to store some data.
Trying to create a user kept pausing the program at the hardfault handler when I tried debugging. Where am I going wrong? Are there any good resources for this microcontroller regarding using the flash memory to store data?
#include "user.h"
#include <string.h>
#include <stdio.h>
#include "stm32f4xx_hal.h"
#include "stm32f4xx_hal_flash.h"
#define ADDR_FLASH_SECTOR_6 ((uint32_t)0x08040000)
#define FLASH_USER_START_ADDR ADDR_FLASH_SECTOR_6
#define USER_SIZE sizeof(User)
void createUser(const char* userID, const char* password, uint8_t tier) {
if (userExists(userID)) {
return;
}
User newUser;
strncpy(newUser.userID, userID, USER_ID_LENGTH);
newUser.userID[USER_ID_LENGTH] = '\0';
strncpy(newUser.password, password, PASSWORD_LENGTH);
newUser.password[PASSWORD_LENGTH] = '\0';
newUser.tier = tier;
HAL_FLASH_Unlock();
FLASH_Erase_Sector(6, VOLTAGE_RANGE_3);
for (uint32_t address = FLASH_USER_START_ADDR; address < FLASH_USER_START_ADDR + MAX_USERS * USER_SIZE; address += USER_SIZE) {
User tempUser;
memcpy(&tempUser, (void *)address, USER_SIZE);
if (strlen(tempUser.userID) == 0) {
for (uint32_t i = 0; i < USER_SIZE; i += 4) {
uint32_t dataToWrite = *(uint32_t *)((uint8_t *)&newUser + i);
HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, address + i, dataToWrite);
}
break;
}
}
HAL_FLASH_Lock();
}
bool userExists(const char* userID) {
User tempUser;
for (uint32_t address = FLASH_USER_START_ADDR; address < FLASH_USER_START_ADDR + MAX_USERS * USER_SIZE; address += USER_SIZE) {
memcpy(&tempUser, (void *)address, USER_SIZE);
if (strcmp(tempUser.userID, userID) == 0) {
return true;
}
}
return false;
}
void getUserPassword(const char* userID, char* outPassword) {
User tempUser;
for (uint32_t address = FLASH_USER_START_ADDR; address < FLASH_USER_START_ADDR + MAX_USERS * USER_SIZE; address += USER_SIZE) {
memcpy(&tempUser, (void *)address, USER_SIZE);
if (strcmp(tempUser.userID, userID) == 0) {
strncpy(outPassword, tempUser.password, PASSWORD_LENGTH + 1);
return;
}
}
}