[alsa-devel] [PATCH 2/8] firmware: Sigma: Skip header during CRC generation
lars at metafoo.de
Mon Nov 28 08:56:33 CET 2011
On 11/25/2011 09:00 PM, Mike Frysinger wrote:
> On Friday 25 November 2011 03:55:42 Lars-Peter Clausen wrote:
>> On 11/24/2011 06:21 PM, Mike Frysinger wrote:
>>> On Thursday 24 November 2011 07:48:21 Lars-Peter Clausen wrote:
>>>> The firmware header is not part of the CRC, so skip it. Otherwise the
>>>> firmware will be rejected due to non-matching CRCs.
>>> that's because you didn't compare to the right value ;). include the CRC
>>> -> compare to 0. omit the CRC -> compare to the CRC value.
>> Does this really work if the CRC is inserted somewhere in the middle of the
> i don't think the position matters to the CRC algorithm used by sigmadsp.
> math principle: a ^ b ^ c is the same thing as b ^ a ^ c and c ^ b ^ a.
If CRC algorithms were commutative they would be pretty weak, I guess ;)
> i could be wrong as to the CRC algo used though. simple enough for you to
> check -- i implemented this firmware code based on a spec i wrote up for the
> sigmadsp peeps; i never actually had real firmware to test with.
It does not work.
More information about the Alsa-devel