RE: Flash Read/Write fails after OTA DFU

A.P — Tue, 22 Oct 2019 13:57:11 GMT

Hi Sigurd!

Using nrfjprog -e did help with our problem, thanks for that.
Am I understanding correctly when I say that whenever the bootloader size changes- for example when moving from 'non secure DFU over USB bootloader', to 'secure DFU OTA bootloader' or vice versa- I will need to erase the flash?

Thanks

RE: Flash Read/Write fails after OTA DFU

Sigurd — Tue, 15 Oct 2019 09:25:00 GMT

Hi,

You should compile the project with preprocessor symbol DEBUG defined, it should then print the error-code instead of "Fatal error".

Anyways, as part of fds_init() -> flash_subsystem_init(), in flash_bounds_set() we check to see if a bootloader_addr is written to flash or not. If bootloader_addr is not found, fds will use the last 3(FDS_VIRTUAL_PAGES) pages at the end of the flash for fds data. If it finds a valid bootloader_addr, it will place the fds data below the bootloader location. In SDK 15.3 the bootloader_addr is stored in the MBR. It could be that bootloader_addr is not found, but you still have the bootloader or bootloader settings page still present in flash, and the fds then fails to initialize.

Try to erase the flash completely, using nrfjprog -e , and then flash the flash_fds example again.