pstorage block size

RE: pstorage block size

Mohamed O.Abouzeid — Mon, 20 Jul 2015 19:32:07 GMT

it doesn't work with softdevice at all

RE: pstorage block size

mira67 — Sat, 13 Sep 2014 00:19:43 GMT

Hi Håkon Alseth , I am using this example code, but the op_code returned from the example_cb_handler is always 0x02, PSTORAGE_STORE_OP_CODE 0x02, why it this? Before the example code, I use ble_stack_init() to enable softdevice, anything missing?

RE: pstorage block size

kk — Wed, 13 Aug 2014 07:35:33 GMT

thank you very much, i made it.

RE: pstorage block size

Sébastien Despont — Wed, 13 Aug 2014 06:31:41 GMT

Here is the signature of the handler :

void pstorage_cb_handler(pstorage_handle_t * handle, uint8_t op_code, uint32_t result, uint8_t * p_data, uint32_t data_len)

RE: pstorage block size

kk — Wed, 13 Aug 2014 06:28:46 GMT

Hi,Håkon Alseth! I want to ask you how do you creat and initialize your example_cb_hanlder? Because I did as what you said and return a NRF_ERROR_NULL when running NULL_PARAM_CHECK(p_module_param->cb);

RE: pstorage block size

Håkon Alseth — Tue, 05 Aug 2014 13:46:10 GMT

That's true! thanks for pointing that out. Will fix that ASAP.

RE: pstorage block size

Sébastien Despont — Tue, 08 Jul 2014 11:07:01 GMT

@Håkon Alseth : Your example is not working because the data to store "dummy_data" are defined in a context potentially no longer available when the pstorage queue (asynchronous) will process the task .

RE: pstorage block size

Håkon Alseth — Thu, 19 Jun 2014 14:44:43 GMT

The total allocated space by the pstorage is set by: block_size * block_count = total flash space

for instance:

static pstorage_handle_t m_p_example_id;
...
static void example_pstorage_init()
{
	uint32_t err_code;         
	pstorage_module_param_t p_example_param;	
	
	// Setup pstorage with 60blocks of 16byte in each.
	p_example_param.block_size  = 0x10; // recommended to be >= 4 byte
	p_example_param.block_count = 60;
	p_example_param.cb          = example_cb_handler;

	err_code = pstorage_init();
	APP_ERROR_CHECK(err_code);  
	
	err_code = pstorage_register (&p_example_param, &m_p_example_id);
	APP_ERROR_CHECK(err_code);  
}

This will allocate 960 bytes in flash, divided into 60 blocks of 16 bytes each. The minimum block-size is set by define PSTORAGE_MIN_BLOCK_SIZE in pstorage_platform.h

To store data into one of these blocks, you can do like this:

// Init pstorage for application storage
example_pstorage_init();

// Store some data to first block
{
	uint32_t err_code;         
	
	uint16_t dummy_block = 0;
    // Must be static as the pstorage module processes the queue asynchronously
	static uint8_t dummy_data[16] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
	uint16_t dummy_size = 16;
	uint16_t dummy_offset = 0;
	pstorage_handle_t p_block_id;
	
	err_code = pstorage_block_identifier_get(&m_p_example_id, dummy_block, &p_block_id);
	APP_ERROR_CHECK(err_code);
	
	err_code = pstorage_store(&p_block_id, dummy_data, dummy_size, dummy_offset);
	APP_ERROR_CHECK(err_code);
}

The pstorage_block_identifier_get will specify which instance/ID is trying to access it's chunk of data (ID is written into m_p_example_id, similar to what app_timer/app_gpiote also does) and set p_block_id to the right address corresponding to your block.

Then you store the data using pstorage_store(...).

Since this module uses the softdevice flash API, the events will be processed through the function given into "softdevice_sys_evt_handler_set()".

You can read back the data using this function (after you've gotten the event in the above handler):

err_code = pstorage_load(my_buffer, &p_block_id, dummy_size, dummy_offset);