Very simple SPI bootloader

[mbozic]

Hi,

I'm implementing a simple bootloader which will not use BLE.

• Application will transfer the data from mobile devices using BLE and this data will be stored to external SPI flash memory. I've already managed to make writing/reading data over SPI.
• Custom bootloader should only read and verify data from external SPI flash and write that data to nRF flash. Bootloader should be able to update any address on the chip except itself, meaning that we want this bootloader to be able to update SoftDevice also. After it flashes what it needs to flash, it should go into newly flashed application.

I have trouble understanding vector mapping and how to do it right. Can someone please give an example with a bit more explanation?

Thnx!

[mbozic]

Sorry, not sure if I understood right. I have to use SD_MBR_COMMAND_INIT_SD command for MBR when bootloader finishes it's work so that vector table is forwarded from bootloader to application?

Yes, application will transfer data to SPI flash, and bootloader will only transfer/flash the data to nRF. Yes, app and SD should always be compatible, meaning that when we update the SD, we must update the app with it.

[Vidar Berg]

SD_MBR_COMMAND_INIT_SD forwards interrupts from the MBR to the vector table located at 0x1000. With this the MBR stops forwarding the interrupts directly to the bootloader.

[mbozic]

Ok, will try. Thank you!

[Vidar Berg]

No problem:) P.S. think new questions not directly related to my answer should be posted as a new questions to better fit the QA format of this page. This should make it easier for others to find a solution while searching for a particular subject. So please accept answer above, and make a separate thread if new questions arises.