Hi,
I am currently using the NVS library with the nRF9160 and an external SPI-NOR flash device (MX25R6435F). I am getting concerned with the NVS library causing issues, and generally being quite slow, so I am exploring directly using the zephyr flash library to save and read flash.
One of the reasons for this, is I only save log blocks of a known size that doesn't change - 4096 bytes. So using the allocation table in NVS for example, is a lot of wasted work - I can say flash block 'x' is at 'y' address.
I assumed it would be a simple as using the functions flash_read() and flash_write(). I have used flash_erase() to erase the whole flash chip with NVS as it was A LOT quicker that using the nvs_clear().
What I find, is that although I get no errors, I cannot read back the bytes I write to an address, even though I can verify that its going into teh same SPI_NOR driver functions as NVS was, and I cannot understand what is different.
Below is some example code. I never get an error so I can't work out what going wrong, but essentially I save a known array of data, then read it back, and it always reads 0. Some of the functions are other functions that I use in my code so wont work if you just copy and paste (Just the stuff to do with printing to terminal).
int test_flash_block_save(struct device *dev, int num)
{
err = flash_write(dev, (num * BLOCK_SIZE), &demo_flash_block, BLOCK_SIZE);
if (!err)
{
char *str = malloc((BLOCK_SIZE*2));
//Print the flash block in hex
print_human_readable_hex(str, demo_flash_block, BLOCK_SIZE);
print_to_com(uart_dev3, "[D] Flash Block - ", str, ALWAYS_PRINT);
free(str);
return 0;
}
return err;
}
int test_flash_block_read(struct device *dev, int num)
{
int err = 0;
err = flash_read(dev, (num*BLOCK_SIZE), &temp_data, BLOCK_SIZE);
if(!err)
{
char *str = malloc((BLOCK_SIZE*2));
print_human_readable_hex(str, temp_data, BLOCK_SIZE);
print_to_com(uart_dev3, "[D] Flash Block - ", str, ALWAYS_PRINT);
free(str);
return 0;
}
return err;
}
/* In Main */
flash_dev = DEVICE_DT_GET(DT_N_NODELABEL_mx25r64);
test_flash_block_save(flash_dev, 0);
test_flash_block_read(flash_dev, 0);
/* end */
Any suggestions would be useful.
SDK 1.6.1 - Modem FW 1.3.0 - Own design PCB
Thanks,
Damien
