Comparing linux kernel trees.

Comparing linux kernel trees.

[James Courtier-Dutton]

Hi,

I have been given a linux kernel sources tar file.
It contains a modified version of the linux kernel.
It is just source files, without any "git" history.
What I would like to do is compare this with the mainline linux kernel
git tree, and find the tag from the kernel git tree that this source
code is most similar to.
E.g. Finding the source code is really kernel 3.2.1 with some minor changes.
My plan at the moment is just to automate a checkout of every git tag,
then run diff -ur on it, and then choose the smallest diff file
output.
But, has anyone got a better method?

Kind Regards

James

Re: Comparing linux kernel trees.

[Clemens Ladisch]

James Courtier-Dutton wrote:
> I have been given a linux kernel sources tar file.
> It contains a modified version of the linux kernel.
> It is just source files, without any "git" history.
> What I would like to do is compare this with the mainline linux kernel
> git tree, and find the tag from the kernel git tree that this source
> code is most similar to.

The kernel *knows* which version it is.

> My plan at the moment is just to automate a checkout of every git tag,
> then run diff -ur on it, and then choose the smallest diff file
> output.
> But, has anyone got a better method?

head -5 Makefile


Regards,
Clemens

Re: Comparing linux kernel trees.

[James Courtier-Dutton]

On 20 January 2013 13:27, Clemens Ladisch <clemens@ladisch.de> wrote:
> James Courtier-Dutton wrote:
>> I have been given a linux kernel sources tar file.
>> It contains a modified version of the linux kernel.
>> It is just source files, without any "git" history.
>> What I would like to do is compare this with the mainline linux kernel
>> git tree, and find the tag from the kernel git tree that this source
>> code is most similar to.
>
> The kernel *knows* which version it is.
>
>> My plan at the moment is just to automate a checkout of every git tag,
>> then run diff -ur on it, and then choose the smallest diff files
>> output.n
>> But, has anyone got a better method?
>
> head -5 Makefile
>
I forgot to mention that in this particular situation, use of the
Makefile does not help.
The linux tree is a tar file to tar over the top of an existing
mainline tree. e.g. Kernel 3.2
It includes the following directories:
drivers
firmware
include
sound

I was wanting to somehow take the include directory, and find out
which kernel version best matches the include in the tar file.
The do the same for the other directories.
I guess I am looking for a sort of git bisect, but instead of finding
a bug, finding a version that best matches some source files.

In the mean time, I have done the diff -ur method on various tags, and
found that kernel 3.2.5 is the best match.
I now have a much smaller patch file, that I can start to get working
with the latest git tree.

Kind Regards

James