Retrieve saved info on restard with pstorage module

[ppatierno]

Hello,

I need to store some app configuration on the FLASH and I'd like to use the features of pstorage module. I don't understand the following thing ...

When the application starts, it uses the pstorage_register (after the pstorage_init of course) to register itself to the pstorage module and then uses it with load and store feature. On restart I can't read what I stored on the previous execution. How for each reboot of application the pstorage knows what's my app FLASH area with my saved info ? I can't find this information ...

Thanks. Paolo.

rgr_cfg.c rgr_cfg.h

[Susheel Nuguru]

Hi ppatierno,

I am sure this question has been asked many times here, but I will try to answer you. pstorage_register will reserve flash page(s) and the flash page number it reserves depend on the the settings in pstorage_platform.h and the sequence of pstorage_register.

For exampleyou code has something like this:

pstorage_init
.....
.....
pstorage_register two pages --> returns block_id1
......
......
pstorage_register three pages -->return block_id2

If the sequence of these two register function never changes over system reboots then they will always register the same physical flash page numbers, the block_id1 and block_id2 have same physical address mapping in this case and you can safely write and read your information over reboots.

but if pstorage_register is done depending on some state machine after reboot, and if the order changes like this after reset

pstorage_init
.....
.....
pstorage_register three pages -->return block_id2
......
......
pstorage_register two pages  --> returns block_id1

Then the block_id to physical address mapping has changed and you wont find the information you stored at the block_id you registered before this reboot.

[Susheel Nuguru]

I did this

    device_manager_init(erase_bonds);
	//pstorage_init();
    db_discovery_init();
    scheduler_init();
    gap_params_init();
    service_init();
    advertising_init();
    conn_params_init();
	
	//rgr_cfg_init();
	
    // Start execution.
    //err_code = ble_advertising_start(BLE_ADV_MODE_FAST);
    //APP_ERROR_CHECK(err_code);
    param.block_size  = 0x10;
    param.block_count = 1;
    param.cb          = rgr_cfg_pstorage_cb_handler;

    pstorage_register(&param, &m_storage_handle);
    


       	    	printf("rgr_cfg_load\r\n");
                rgr_cfg_load();
        
				if(*ptr != 16) {
                printf("rgr_cfg_save\r\n");
                rgr_cfg_save();

                }
                else{
				printf("rgr_cfg_load\r\n");
                rgr_cfg_load();

                }


	// Enter main loop.
    for (;;)
    {
        app_sched_execute();
        power_manage();
    }
}



static void rgr_cfg_pstorage_cb_handler(pstorage_handle_t *p_handle,
										uint8_t op_code,
										uint32_t result,
										uint8_t *p_data,
										uint32_t data_len)
{
    uint32_t err_code;
	printf("p_handle=%d, op_code=%d, result=%d, p_data=%d, data_len=%d\r\n", p_handle, op_code, result, p_data, data_len);
	
	for (int i = 0; i < data_len; i++)
	{
		printf("p_data[%x] = %d\r\n", i, p_data[i]);
	}
    
     printf("delay 5 sec\r\n");
    restart = true;
    err_code      = app_timer_start(m_sec_req_timer_id, SECURITY_REQUEST_DELAY, NULL);
            APP_ERROR_CHECK(err_code);
 
}

and did a reset in the timer callback