SoftDevice size value in DFU init packet

RE: SoftDevice size value in DFU init packet

Pierre cgwi22 — Fri, 16 Apr 2021 09:41:38 GMT

Thanks for the link, that's exactly what we needed. So for our SoftDevice size in the init packet, we can see these bytes starting at position 20:

0xE8 0x9B 0x09
==> 11101000 10011011 00001001
==> 0001001 0011011 1101000 after removing MSB and reverse order
==> 151016 in decimal so now it works.

Our problem is solved, thanks!

RE: SoftDevice size value in DFU init packet

tesc — Wed, 14 Apr 2021 14:41:35 GMT

Hi,

You cannot read values directly out of the file in hex like that, due to the way integers are stored in the protobuf format. Values 0-127 will read as normal, but anything above that will be different. Also, the number of bytes used for each value will vary, so the location of values may change depending on the size of the previous values. For details on the encoding, see the Encoding chapter of the Protocol Buffers developer guide from Google.

For reading out the values, I recommend using a protobuf reading library. You can also have a look at the nrfutil source for reference.

Regards,
Terje

RE: SoftDevice size value in DFU init packet

Pierre cgwi22 — Wed, 14 Apr 2021 07:38:31 GMT

Hi,

Thanks for your answer, but even with the protobuf, the dfu-cc.pb.c and dfu-cc.pb.h files, the fields do not seem to be what we can see in the init packet (.dat file).

We use nRF Util version 5.2.0 and this is the result of the "pkg display" command with the corresponding data. We have found some of the values but not the bootloader and SoftDevice sizes:

RE: SoftDevice size value in DFU init packet

tesc — Tue, 13 Apr 2021 10:42:22 GMT

Hi,

De format of the init file (the .dat file in the zip) is protocol buffers (protobuf), and the contents is defined in the file at <sdk folder>/components/libraries/bootloader/dfu/dfu-cc.proto.

Regards,
Terje