Using app_with_dfu jump to bootloader.

[Coldson]

Hi all:

I use the softdevice 2.0.0 and compile bootloader example with "dual bank" on the nrf52 DK,

Running a system that can using DFU from app then jump to bootloader as example hrm did.

After I have a deep study it, I found out that:

1. DFU will sign a value "BOOTLOADER_DFU_START" into "GPREGRET".

2. it will restart using "bootloader_util_app_start(NRF_UICR->NRFFW[0]);" into bootloader.

3. While into bootloader, the main function will check the sign on "GPREGRET"(bool app_reset = (NRF_POWER->GPREGRET == BOOTLOADER_DFU_START);)

4. The DFU flow just as the picture below.

5. And the problem is: it will stuck at dfu_ble_svc_peer_data_set(&m_peer_data); --> dfu_app_handler.c line 110

6. the nrftool DFU on my iPhone will show:

7. If I mark the step 5. line 110, and it will went to the function: "bootloader_util_app_start(NRF_UICR->NRFFW[0]);", but nrftool app on my iPhone still show "Enabling DFU Bootloader"

I think that did not really jump into bootloader, but why? What should I check?

Please correct me if I misunderstanding the DFU flow.

Thx for everyone willing to help me solve this problem.

Update 2016/06/27:

There're no return error code after that break point: err_code = dfu_ble_svc_peer_data_set(&m_peer_data);

and the variable m_peer_data is:

[Hung Bui]

Hi Coldson,

It could be the issue that one of the applications (your application or the bootloader) was using the peripheral (UART or RTC) without configure it properly. When switching from application to bootloader and vise versa, we don't reset all the registers to default state. So it's up to the application to make sure all the register are configured before using it. Also I would suggest to disable any timer, peripheral before branching to bootloader.

Again, if you can provide an demo code that can reproduce the issue it's would be easier for us to track down the problem and find a solution.