How to patch fglrx for installation on kernel 3.7rc7?

I got my answer by combining different posts on the ubuntuforums. This guide will use the 12.10 version of fglrx from the ati site. All these steps are done in a terminal. This guide assumes you have kernel 3.7rc7 installed by following the steps in https://wiki.ubuntu.com/KernelMainlineBuilds. It also assumes you're running Ubuntu 12.04, however the instructions for 12.10 are very similar.

1. Create temporary directory and go to this directory:

   mkdir ~/temp
   cd ~/temp
   

2. Download the ati driver and the patch:

   wget http://www2.ati.com/drivers/linux/amd-driver-installer-catalyst-12.10-x86.x86_64.zip
   wget http://catalyst.apocalypsus.net/files/arch-fglrx-3.7.patch
   

3. Extract the zip and make the .run file executable:

   unzip amd-driver-installer-catalyst-12.10-x86.x86_64.zip
   chmod +x amd-driver-installer-catalyst-12.10-x86.x86_64.run
   

4. Extract the .run file in the ./src directory:

   ./amd-driver-installer-catalyst-12.10-x86.x86_64.run --extract ./src
   

5. Go to the ./src directory and apply the patch:

   cd ./src
   patch -Np1 --verbose < ../arch-fglrx-3.7.patch
   

6. Now build the deb packages for 12.04 (precise), these will go in the parent directory

   ./ati-installer.sh 9.002 --buildpkg Ubuntu/precise
   

7. Go to the parent directory and install the files

   cd ../
   sudo dpkg -i *.deb
   

   If you get an error about version.h and that building the dkms modules failed, this is because the file version.h is misplaced in kernel 3.7rc7. To fix this do

   ln -s /usr/src/linux-headers-3.7.0-030700rc7-generic/include/generated/uapi/linux/version.h /usr/src/linux-headers-3.7.0-030700rc7-generic/include/linux/version.h
   

   and remove and install fglrx again

   sudo apt-get remove "fglrx*"
   sudo dpkg -i *.deb
   

8. Backup your xorg.conf and generate a new one

   sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.bak
   sudo aticonfig --initial -f
   

Reboot it and it should work!