add python script to generate xpadneo kernel patch from sources

[GloriousEggroll]

Allows generating a kernel patch for xpadneo instead of installing via dkms or akmods.

Usage example for kernel 6.19.9 and xpadneo v0.10:

wget https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.19.9.tar.xz
tar -xf linux-6.19.9.tar.xz
git clone https://github.com/atar-axis/xpadneo
cd xpadneo
git checkout v0.10
cd ..
cp xpadneo/generate-xpadneo-patch.py .
./generate-xpadneo-patch.py 6.19.9

Result: xpadneo-kernel-integration.patch

Folder structure:
Parent folder->
(Linux kernel source)
(xpadneo source)
generate-xpadneo-patch.py

Update 3/29/26:
Also generates udev rules and modprobe file needed for xpadneo.

• I agree that my contribution is accepted under the project's existing license terms, and that contributions to
  the module source code are accepted under GPL-2.0-only.

[kakra]

Thanks, this looks useful, I will look into it. It's a perfect opportunity because I'm maintaining a direct kernel patch myself which needs to be updated: kakra/linux#38

[kakra]

Just a quick first review without having it tried for my own kernel patches yet.

[kakra]

@GloriousEggroll I've reworked the patch generator to better fit my workflow, and to reuse files from the source tree instead of hard-coding them in the script. Please review and let me know if this works for you, so I can merge it into xpadneo.

If ready, I'll merge the commits in one squashed commit adding your co-authored-by.

I'm not very fluent in python so I used multiple AI agents to change and review the changes, including some manual cleanups.

Changes:

• The script has been moved to misc.
• The script now expects a git repo as the kernel source, and optionally a second argument for the kernel version.
• Generated output will be written into dedicated output directories.
• Instead of unpacking/copying kernel/xpadneo sources, the script now uses temporary git worktrees.
• Instead of using diff, the script now uses a temporary git commit and exports the generated commit.

You can now run the script from the xpadneo directory without providing a Linux source tree at a predefined location, instead an existing Linux git clone is needed and can be placed anywhere in the file system.