I am new to NRF chips and trying to read, write, and erase to flash using nrf_fstorage. I have looked at the example project flash_fstorage and I am able to successfully read and write to flash but am having trouble with erasing specific pages as there is no example.
For example I set my flash address space to 0x3e000 - 0x3FFFF.
NRF_FSTORAGE_DEF(nrf_fstorage_t fstorage) =
{
/* Set a handler for fstorage events. */
.evt_handler = fstorage_evt_handler,
/* These below are the boundaries of the flash space assigned to this instance of fstorage.
* You must set these manually, even at runtime, before nrf_fstorage_init() is called.
* The function nrf5_flash_end_addr_get() can be used to retrieve the last address on the
* last page of flash available to write data. */
.start_addr = 0x3e000,
.end_addr = 0x3ffff,
};
In main, I setup and write "hello world" to 0x3e000 and "hello sunnn" to 0x3e200.
static char s1[] = "hello world";
static char s2[] = "hello sunnn";
static char read_s1[sizeof(s1)];
static char read_s2[sizeof(s2)];
ret_code_t rc;
nrf_fstorage_api_t * p_fs_api;
p_fs_api = &nrf_fstorage_sd;
rc = nrf_fstorage_init(&fstorage, p_fs_api, NULL);
APP_ERROR_CHECK(rc);
rc = nrf_fstorage_write(&fstorage, 0x3e000, &s1, sizeof(s1), NULL);
APP_ERROR_CHECK(rc);
wait_for_flash_ready(&fstorage);
rc = nrf_fstorage_write(&fstorage, 0x3e200, &s2, sizeof(s2), NULL);
APP_ERROR_CHECK(rc);
wait_for_flash_ready(&fstorage);
Now I try to erase "hello world" using the code below however both strings in flash get cleared.
rc = nrf_fstorage_erase(&fstorage, 0x3e000, 1, NULL); APP_ERROR_CHECK(rc); wait_for_flash_ready(&fstorage);
If I try the either line of code below to erase only "hello sunnn" I gfet the error: addr_is_page_aligned(p_fs, page_addr) check failed in nrf_fstorage_erase() with value 0x10.
// This line
rc = nrf_fstorage_erase(&fstorage, 0x3e000, 3, NULL);
// Or this line
rc = nrf_fstorage_erase(&fstorage, 0x3e200, 1, NULL);
What am I doing wrong?
Below is an image of how I understand it but it is clearly not correct.
