Using GnuK with DFU bootloader

Peter Lebbing peter at
Thu Dec 20 11:51:44 CET 2018

Hello Niibe!

On 20/12/2018 10:06, NIIBE Yutaka wrote:
> I think that you meant four commits which ends by the commit of
> 00039c2419919b396ff11f119820f8cae5ab1d31, right?

Yes, exactly.

> I'll merge them.  Hopefully, before the Congress.

Very cool, thanks!

By the way, when I wrote:

On 18/12/2018 18:59, Peter Lebbing wrote:
> I have tried several things with a Maple Mini with this GnuK and it
> behaved completely normally.

I again didn't communicate very clearly.

I actually did quite a lot of testing. I hooked the GNU debugger up to a
board through SWD, and placed breakpoints at suitable places. Of the
code I've written, I verified that it did what I expected it to do.
Correctly erase the start of flash up to the running GnuK copy. Copy the
new SYS at the start of flash. Verify that the end result is that the
first 4 KiB is byte for byte equal to the first 4 KiB of a release
1.2.11 stock GnuK firmware. Verify that on reGNUal invocation, all but
the first 4 KiB is erased and reGNUal correctly executed. Finally, at
the end, add setting of flash readout protection to the code (which
precludes debugging) and verify that flash is indeed protected. Verify
that if --with-dfu is not supplied, the result is the same as before the
patches, comparing disassembled code. Probably some more stuff. I took
my time testing.

I meant that /in addition to/ all these tests, I also did a test to see
the behaviour of everything I didn't change still appeared to be the

So it was quite silly of me to only mention the latter :-).



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