Bootloader from SDCard

[warcomeb-am]

Hi, 

I need to add to my project that uses NRF5340 a bootloader that reads new firmware from SDCard. Is there an example where I can find information? Someone has just encountered this kind of issue and can tell me some tips?

Thanks

Marco

[Vidar Berg]

Hello Marco,

I'm not aware of any SDK examples that demonstrate DFU via a SD card, unfortunately. Have you considered other supported alternatives such as DFU through BLE or USB?

Best regards,

Vidar

[warcomeb-am]

Hi Vidar,

thanks for the reply. The customer wants to maintain the same behaviour of the previous version of the project (without Nordic device), where the new firmware was stored into SDCard and at reset, the bootloader read the hex from the sdcard, copies the application, removes the file and reboot the device with the new application. Some tips?

Best regards,

Marco

[Vidar Berg]

Hi,

Provided you have enough internal flash, I think the easiest approach might be to have the application load the binary image from your SD card into the MCUBoot's secondary slot (Ref., Image slots, Disc access), then let MCUBoot activate the update on the following reboot by moving the update image from the secondary to the primary slot. Another alternative may be to modify MCUBoot to support serial recovery from an SD card (serial recovery is currently supported through USB/UART).

Best regards,

Vidar

[warcomeb-am]

Dear Vidar Berg ,

During this time I worked on the other parts of the applications, but now it's time for me to finish the application with the bootloader! 

Just to understand better, the code that I need to add to my application is:

• the user copies the file app_update.bin into SDCard
• the application copies the contents of the file into the image_1 region by using the flash_* function
• At the reboot, the bootloader copies the contents of image_1 into image_0 by itself

now the application is updated, right?

Best

Marco

[Vidar Berg]

Dear Marco,

Yes, this should work. The bootloader will check if a new FW update is available in the secondary slot on boot. If there is, it will proceed to copy the image into the primary slot and boot the new application.

Best,

Vidar