nrf_dfu_flash_callback_t changed in SDK 15

[Niclas Heitz]

Hello,

 with SDK15 the definition of the nrf_dfu_flash_callback_t changed from

typedef nrf_fstorage_evt_handler_t dfu_flash_callback_t;

typedef void (*nrf_fstorage_evt_handler_t)(nrf_fstorage_evt_t * p_evt);

typedef struct
{
    nrf_fstorage_evt_id_t   id;         //!< The event ID.
    ret_code_t              result;     //!< Result of the operation.
    uint32_t                addr;       //!< Address at which the operation was performed.
    uint32_t                len;        //!< Length of the operation.
    void                  * p_param;    //!< User-defined parameter passed to the event handler.
} nrf_fstorage_evt_t;

to

typedef void (*nrf_dfu_flash_callback_t)(void * p_buf);

we used the nrf_fstorage_evt_t->result to determine the success of the operation in the callback, but now with the (void* p_buf) we can't do it, because there is no description what data is in this buffer and in what form.

If someone could provide a solution, I would appreciate it.

Thanks in advance and best regards,

Niclas

[Einar Thorsrud]

Hi,

The p_buf pointer will be set to the source buffer (buffer written to flash) by dfu_fstorage_evt_handler(), which calls the callback function. I have not been able to determine why this change was done, though.

[semperfelix]

In the SDK 15.0 there is only one example of this usage that can be found in nrf_dfu_req_handler.c. There it seems that void * p_buf is used a function pointer and not a buffer pointer.

 /* Callback to on_dfu_complete() after updating the settings. */
 dfu_settings_callback = (nrf_dfu_flash_callback_t)(on_dfu_complete);

and above

 static void on_dfu_complete(nrf_fstorage_evt_t * p_evt)
 { blabla }

That implementation make sense (in a way), but contradicts your explanation... Am I looking it the wrong way here?

[Einar Thorsrud]

I think you are looking at it the wrong way, but I have to admit that I am looking at it the first time now (It is vacation time in Norway, so I have not been able to get hold of any of the original developers).

The line you refer to in nrf_dfu_req_handler.c:

dfu_settings_callback = (nrf_dfu_flash_callback_t)(on_dfu_complete);

is essentially just making dfu_settings_callback be a function pointer to on_dfu_complete(), which is a static function implemented in the beginning of the file. This is subsequently passed to nrf_dfu_settings_write(), which calls nrf_dfu_flash_store() and via a few more function calls it ends up in the dfu_fstorage_evt_handler(), which calls the registered callback function (on_dfu_complete() in this case).

[semperfelix]

Okay... but the question still remains... according to the online documentation found here:

http://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.0.0%2Fgroup__sdk__nrf__dfu__flash.html&resultof=%22nrf_dfu_flash_callback_t%22%20

the callback is described the following way:

typedef void(* nrf_dfu_flash_callback_t)(void *p_buf)

nrf_fstorage event handler function for DFU fstorage operations.

This function will be called after a flash operation has completed.

Where is the function prototype defined and what parameters has the callback function?

[Einar Thorsrud]

Well, the prototype for the function is given by  typedef void(* nrf_dfu_flash_callback_t)(void *p_buf) as you have noted, so it would be e.g. void function_name(void * p_buf). It seems that the on_dfu_complete() was not updated for SDK 15, so that it does not match the function pointer prototype (nrf_fstorage_evt_t * instead of void *), but that does not have any practical implications in this case.