Creating a Kernel patch after our own customizations

kushalkoolwal · 03-10-2008, 08:32 PM

Hi,

I downloaded 2.6.24 kernel and I made the following changes:

Code:

1. Changes to /usr/src/linux/drivers/video/Makefile
2. Changes to /usr/src/linux/drivers/video/Kconfig
3. Created a new directory /usr/src/linux/drivers/video/via and added some new files there.

Now I would like to create a patch which my users can use after they install the 2.6.24 kernel. How can I create a patch which incorporate changes such as adding a entire new directory like "via" in this case.

Thanks

Simon Bridge · 03-11-2008, 03:19 AM

1. Make sure your additions are GPLv2 compliant.
2. Make sure that what you want to do and how you are going about it match.
http://kernelnewbies.org/Drivers
http://www.linuxchix.org/content/cou...acking/lesson9

To make a patch - cd into the top of the modified source tree and use diff with the recursive flag... i.e.

cd /usr/src
diff --unified --recursive --new-file linux-2.6.22 linux > patch-2.6.22
gzip patch-2.6.22

Note the pattern: diff -options oldfile newfile > patch
So - oldfile = the old linux source tree, here it's the /usr/src/linux-2.6.22 directory and all the new goodness is in /usr/src/linux

You user applies the patch by cd-ing into the unpatched kernel tree and using zcat and patch:

cd /usr/src
zcat patch-2.6.22.gz | patch -p0 -E

kushalkoolwal · 03-11-2008, 03:26 AM

Awesome!!! No wonder you are called Guru.

Quote:

Originally Posted by Simon Bridge

1. Make sure your additions are GPLv2 compliant.

When you say GPLv2 compliant, are you referring to the coding style or the licensing issues related to releasing the source code and all that?

Simon Bridge · 03-11-2008, 04:55 AM

License issues.
http://www.gnu.org/licenses/gpl-faq.html
Using only gpl code avoids them.

As well, applying a proprietary patch "taints" the kernel. This makes it difficult to get outside help should things go wrong. Like - don't go running to the kernel mailing lists.

You will be distributing it, so you need to give serious thought to how you will be licensing your patch. You also need to make sure the recipients understand how this works. It's a pain at first, but you get used to it - also, you end up more aware of the chains that proprietary vendors put on you, often without realizing it. Next thing you know, you're free... it's a slippery slope.

Oh: and "guru" just means I've made x-number of posts. I could as easily be "LQ Addict" but that's less cool