WLAN Pi kernel

This repository contains build scripts and configurations for the WLAN Pi custom Linux kernel, supporting both Raspberry Pi 4/CM4 and Raspberry Pi 5 hardware platforms.

Building kernels

Local build

The build script supports building kernels for different hardware variants:

./build-kernel.sh           # Build both v8 (Pi 4) and 2712 (Pi 5) kernels (default)
./build-kernel.sh v8        # Build only Pi 4/CM4 kernel (v8, 4KB pages)
./build-kernel.sh 2712      # Build only Pi 5 kernel (2712, 16KB pages)

Building for different Debian releases:

# Default: Debian Trixie
./build-kernel.sh

# Target Debian Bookworm
DEBIAN_RELEASE=bookworm ./build-kernel.sh
DEBIAN_RELEASE=bookworm ./build-kernel.sh v8

Requirements:

• Cross-compilation toolchain: gcc-aarch64-linux-gnu
• Build dependencies: build-essential, git, libncurses-dev, flex, bison, libssl-dev, etc.

Output packages:

When building v8 only (for trixie):

• wlanpi-kernel-trixie-v8_*.deb
• wlanpi-kernel-headers-trixie-v8_*.deb

When building 2712 only (for trixie):

• wlanpi-kernel-trixie-2712_*.deb
• wlanpi-kernel-headers-trixie-2712_*.deb

When building both (for trixie):

• All of the above, PLUS
• wlanpi-kernel-trixie_*.deb - Unified dual-kernel package for universal images

Note: Replace trixie with bookworm in package names when building with DEBIAN_RELEASE=bookworm

CI/CD build with GitHub actions

The repository includes automated builds via GitHub Actions:

Automatic builds: Triggered on push to branch (builds both kernels by default)

Manual builds:

1. Go to Actions → Build and archive WLAN Pi kernel package
2. Click "Run workflow"
3. Select kernel variant: both, v8, or 2712
4. Click "Run workflow" button

Built packages are uploaded as separate artifacts per variant for easy download.

Kernel variants

• v8 (Pi 4/CM4): 4KB page size, CONFIG_ARM64_4K_PAGES, uses bcm2711_defconfig
• 2712 (Pi 5): 16KB page size, CONFIG_ARM64_16K_PAGES, uses bcm2712_defconfig
• Dual package: Contains both kernels; [pi4]/[pi5] conditional filters in config.txt select the matching kernel at boot

See DUAL-KERNEL.md for detailed information about the dual-kernel packaging approach.

Quick start

1. Clone the Repository:

   git clone https://github.com/WLAN-Pi/wlanpi-kernel.git
   cd wlanpi-kernel

2. Build kernels:

   ./build-kernel.sh

3. Install on target device:

   # For Pi 4/CM4:
   sudo dpkg -i output/wlanpi-kernel-trixie-v8_*.deb
   
   # For Pi 5:
   sudo dpkg -i output/wlanpi-kernel-trixie-2712_*.deb
   
   # For universal image (works on both):
   sudo dpkg -i output/wlanpi-kernel-trixie_*.deb