How to make it run application when there is a bootloader in the nRF52

[Alice]

Hi,

I'm using the bootloader in nRF5_SDK V12.0 with nRF52832. I have some problems want to know:

1. How to make it run application first after I program softdevice,bootloader and application? I found that it runs the bootloader and broadcast as "DfuTarg". I know it can set m_boot_settings in nRF5_SDK V11.

2. After I finish the OTA, it can run the application. However, if I just do a little modification in my application and then program it, it would neve run the application,it runs the bootloader. Is it normal?

3. I want to use AT command received by the UART to make it switch to bootloader instead of using a button. I do that like this: In my application,when received the AT command, I will write a value to the flash(the last page in the flash) using fstorage then do a reset. In the bootloader, I add some code to read the flash to check the value. So my question is I should use the fstorage or do it like flashwrite example in SDK? Which way would you suggest? Thanks.

[bjorn-spockeli]

Hi Alice,

1. You have to generate the bootloader settings page that sets the application crc and the bank 0 status flag to NRF_DFU_BANK_VALID_APP, see this page in the nrfutil documentation.
2. The bootloader will check the CRC of the application against the application CRC stored in the bootloader settings page. If you flash a new application to your device, then the CRCs will not match. Thus, you have to update the bootloader settings page that corresponds to your new application.
3. If you're only writing one value to flash then I suggest that you use the SoftDevice Flash API, see sd_flash_write documentation in the S132 SoftDevice API documentation.

Best regards

Bjørn

[Alice]

The settings page as follow:

0x0007F000: FAD8B19F 00000001 00000001 00000001   |................|
0x0007F010: 00000000 00000000 00005EA8 5221C273   |.........^..s.!R|
0x0007F020: 00000001 00000000 00000000 00000000   |................|
0x0007F030: 00000000 00000000 00000000 00000000   |................|
0x0007F040: 00000000 00000000 00000000 00000000   |................|
0x0007F050: 00000000 00000000 00000000 FFFFFFFF   |................|
0x0007F060: FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF   |................|
0x0007F070: FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF   |................|
0x0007F080: FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF   |................|
0x0007F090: FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF   |................|
0x0007F0A0: FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF   |................|
0x0007F0B0: FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF   |................|
0x0007F0C0: FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF   |................|
0x0007F0D0: FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF   |................|
0x0007F0E0: FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF   |................|
0x0007F0F0: FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF   |................|

We can see that the CRC stored on the bootloader settings page is 0x5221C273, then I debug it and set a breakpoint at theif (crc != s_dfu_settings.bank_0.image_crc), the crc is 0xDD2F1460. So it wouldn't run the application. Is there any problem for the crc32_compute function? The SDK I use is nRF5_SDK_12.0.0_12f24da.

Besides, I found another problem.For example, my application is app.hex and use app.hex to generate the setting page app_setting.hex. Softdevice and bootloader have been flashed to the chip. Then I use app_setting.hex to generate the ZIP and use nRF Toolbox to update the fireware, it failes. The APP reported as completed(just 1% and then 100%,veyy soon), in fact the device is not updated. However, if I use app.hex to generate the ZIP (the same way)and use nRF Toolbox to update the fireware, it's OK. The version of APP is 4.2.0. I use bootloader_secure from the nRF5_SDK_12.1.0_0d23e2a, the problem still exist.