Re: [RFC] lib: crc8: add new library module providing crc8algorithm

From: Arend van Spriel
Date: Tue May 24 2011 - 06:01:47 EST


On 05/24/2011 11:44 AM, Alan Cox wrote:
On Tue, 24 May 2011 09:45:47 +0200
"Arend van Spriel"<arend@xxxxxxxxxxxx> wrote:

On 05/22/2011 04:19 PM, Alan Cox wrote:
Is it just used for wireless in this form ?

See the n_gsm and bluetooth code for what I think is the same crc
algorithm but in reverse bit order .
Hi Alan,

Look into the code in n_gsm and bluetooth code. The algorithm is the
same, but except for the bit order it also is using a different
polynomial. My current implementation has a fixed table. I could do the
table generation runtime with the polynomial and the bit order as
parameters. That would make it more general purpose.
Probably not worth it - its so tiny a piece of code anyway (< 500 bytes
or so) that it's going to be bigger not smaller if you do that !

Hi Alan,

Not sure whether you mean the source code or the object code. I build kernel with debug symbols so the sizes are bit higher.

fixed table: -rw-r--r-- 1 arend arend 1859 2011-05-24 11:53 crc8.o
custom table: -rw-r--r-- 1 arend arend 2215 2011-05-24 11:58 crc8.o

The size increase is not that big.

Gr. AvS

--
Almost nobody dances sober, unless they happen to be insane.
-- H.P. Lovecraft --


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