Bootloader and nRF Connect can't resume DFU

[Cyril]

Hello,

I'm testing the bootloader with SDK v.15 and I found a state when DFU won't resume (on BLE transport).

I crashed nRF Connect randomly, in that case, between the first and second object. Here is the log:

<debug> app: Shutting down transports (found: 1) // BLE disconnected from remote
<debug> nrf_dfu_req_handler: Handle NRF_DFU_OP_OBJECT_CREATE (data) // Second block creation
<debug> nrf_dfu_flash: nrf_fstorage_erase(addr=0x0x00051000, len=1 pages), queue usage: 0
<debug> nrf_dfu_req_handler: Creating object with size: 4096. Offset: 0x00001000, CRC: 0x1B4AC781
<debug> nrf_dfu_req_handler: Request handling complete. Result: 0x1
<debug> nrf_dfu_flash: Flash erase success: addr=0x00051000, pending 0
<debug> nrf_dfu_ble: Advertising...

Then, it won't resume, even after reset, here is the log pointing out the error:

<debug> nrf_dfu_req_handler: Handle NRF_DFU_OP_OBJECT_EXECUTE (command)
<debug> nrf_dfu_settings: Writing settings...
<debug> nrf_dfu_settings: Erasing old settings at: 0x000FF000
<debug> nrf_dfu_flash: nrf_fstorage_erase(addr=0x0x000FF000, len=1 pages), queue usage: 0
<debug> nrf_dfu_flash: nrf_fstorage_write(addr=0x000FF000, src=0x2000A7C0, len=440 bytes), queue usage: 1
<debug> nrf_dfu_req_handler: Writing valid init command to flash.
<debug> nrf_dfu_req_handler: Request handling complete. Result: 0x1
<debug> nrf_dfu_ble: Set receipt notif
<debug> nrf_dfu_req_handler: Handle NRF_DFU_OP_RECEIPT_NOTIF_SET
<debug> nrf_dfu_req_handler: Request handling complete. Result: 0x1
<debug> nrf_dfu_req_handler: Handle NRF_DFU_OP_OBJECT_SELECT (data)
<debug> nrf_dfu_req_handler: crc = 0x1B4AC781, offset = 0x1000, max_size = 0x1000
<debug> nrf_dfu_req_handler: Request handling complete. Result: 0x1
<debug> nrf_dfu_flash: Flash erase success: addr=0x000FF000, pending 1
<debug> nrf_dfu_flash: Flash write success: addr=0x000FF000, pending 0
<debug> nrf_dfu_req_handler: Handle NRF_DFU_OP_OBJECT_EXECUTE (data)
<error> nrf_dfu_req_handler: Invalid data. expected: 4096, got: 0
<debug> nrf_dfu_req_handler: Request handling complete. Result: 0x8
<warning> nrf_dfu_ble: DFU request 4 failed with error: 0x8

The issue is that s_dfu_settings.progress.firmware_image_offset equals s_dfu_settings.progress.firmware_image_offset_last.

Do you have any idea how to fix that issue?

That issue looks critical as I simply can't resume the DFU if I try to send the same package. Here is a screenshot of nRF Connect:

Let me know if you have more question.

Best

[tesc]

Hi,

Thanks to your report and detailed descriptions our software engineers have identified an issue: If the DFU is aborted at one particular moment, in-between two objects, it may enter the state that you are experiencing.

It only happens on disconnect + reconnect, as that does not trigger a reset of the DFU target.

The problem is that the connection is lost immediately after a create_object, and when the connection is reestablished the DFU controller performs an execute before resuming the update. They propose fixing it by resetting the settings on disconnect, either through (a potentially modified) nrf_dfu_settings_init(), or as you suggested by doing a reset.

Regards,
Terje