kbuild

A Docker based script that builds Debian packages for the Linux kernel as well as for external kernel modules.

Requirements

While the script can be run in any Debian based Linux Distribution (given all necessary dependencies are installed), it has only been tested runnning Debian Stretch on amd64 compatible machines. Therefore, it is strongly recommended to make use of Docker which allows for building the kernel and module packages in a defined environment - even with Windows or Mac OS as host OS. The kbuild script has been tested with Docker version 17.12.0-ce.

Installation

Make sure Docker is installed and in the search PATH - there is plenty of information how to do that on the internet, https://docs.docker.com is a good start.

Installation of kbuild itself is easy. Just download the kbuild script from this repository and put it in your executeable search PATH, e.g.:

sudo wget https://ntc.githost.io/nextthingco/kbuild/raw/unstable/kbuild -O /usr/local/bin/kbuild

When you run kbuild the first time on your system, it will pull the latest Docker container from the registry attached to this repository. The Docker container can also be manually built which is described below in the Hacking section.

Quickstart

So you want to build your own Linux kernel packages for Debian? The following will walk you through building a customized kernel for C.H.I.P.

Step 1: Initialize

mkdir my_kernel
cd my_kernel
kbuild init chip

This will create the following files in the my_kernel directory:

kbuild.cfg
multi_v7_defconfig
src/linux

Step 2: Change Kernel configuration

Let's add some feature in the kernel configuration:

kbuild linux-nconfig

Step 3: Build, all of it!

kbuild all

After step 3 is completed you'll find a bunch of .deb packages in my_kernel:

linux-firmware-image-4.4.13-chip_4.4.13-25836_arm.deb
linux-headers-4.4.13-chip_4.4.13-25836_arm.deb
linux-image-4.4.13-chip_4.4.13-25836_arm.deb
linux-libc-dev_4.4.13-25836_arm.deb
rtl8723bs-mp-driver-common_4.4.2-25836.20160519-BTCOEX20151223-654a-ntc-1_all.deb
rtl8723bs-mp-driver-dkms_4.4.2-25836.20160519-BTCOEX20151223-654a-ntc-1_all.deb
rtl8723bs-mp-driver-modules-4.4.13-chip_4.4.2-25836.20160519-BTCOEX20151223-654a-ntc-1+4.4.13-25836_all.deb
rtl8723bs-mp-driver-source_4.4.2-25836.20160519-BTCOEX20151223-654a-ntc-1_all.deb
chip-mali-modules-4.4.13-chip_1.0-0-ntc-0+4.4.13-25836.deb

Copy and install them onto your C.H.I.P!

Step 4: Save defconfig

If you want to save the changes you've made into a new defconfig:

kbuild linux-savedefconfig

External kernel modules

Currently the following external kernel modules are supported:

• RTL8723 DS / BS Wifi drivers
• Mali 400 drivers for C.H.I.P

Configuration files

The script needs to know certain parameters, e.g. the architecture to build for and where to find the sources for the kernel and external modules. These can be specified either as environment variables or be read from a configuration file usually named kconfig.cfg.

Generic options

• ARCH: Target architecture, e.g. arm, or arm64
• DPKG_ARCH: Debian package architecture, can be arm, armhf or arm64
• DEBFULLNAME: Name or Company who builds the .deb packages
• DEBEMAIL: Contact e-mail of the packager
• CROSS_COMPILE: Cross compiler toolchain prefix e.g. arm-linux-gnueabihf-

Linux options

• LINUX_FLAVOR: Random flavor name e.g. chip
• LINUX_DIST: Debian release e.g. jessie or stretch
• LINUX_REPO: Git repository to clone Linux source code from, e.g. git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
• LINUX_BRANCH: Branch of the Linux repository, e.g. master
• LINUX_CONFIG: e.g. multi_v7_defconfig

RTL8723 options

• RTL8723_REPO: Git repository to clone the RTL8723 source code from, e.g. https://github.com/nextthingco/rtl8723bs
• RTL8723_BRANCH: Branch of the RTL8723 repository, e.g. ja/8723-update

MALI options

• CHIP_MALI_BRANCH: Branch of the CHIP Mali repository, e.g. debian
• CHIP_MALI_REPO: Git repository to clone CHIP Mali source code from, e.g. git://github.com/nextthingco/chip-mali

Usage

 kbuild [OPTIONS] COMMAND

The kbuild script is a convenient wrapper running the kbuild.sh script inside a Docker container.

If no configuration file is specified, it looks for a file named kbuild.cfg in current directory.

COMMANDS:
  all                  Builds everything specified in the kbuild.cfg
  linux                Only build Linux Debian packages
  rtl8723              Only build RTL8723 Wifi drivers packages
  chip-mali            Only build Mali GPU drivers for C.H.I.P

  linux-nconfig        Allows to modify the Linux configuration
  linux-savedefconfig  Save Linux defconfig

  shell <CMD>          Run interactive bash shell in Docker container
  update-image         Tries to pull the lates version of the Docker image


OPTIONS:
  -h               Show this help
  -v               Show verbose output
  -i IMAGE         Use custom command in Docker container image

Configuration files

The configuration for C.H.I.P using building Kernel 4.4.13, RTL8723BS Wifi drivers and Mali drivers:

### kbuild config for CHIP
ARCH=arm
DPKG_ARCH=armhf
DEBFULLNAME="Next Thing Co."
DEBEMAIL="[email protected]"
CROSS_COMPILE=arm-linux-gnueabihf-
####
LINUX_FLAVOR="chip"
  LINUX_DIST="stretch"
LINUX_BRANCH="debian/4.4.13-ntc-mlc"
  LINUX_REPO="git://github.com/nextthingco/CHIP-linux"
LINUX_CONFIG="multi_v7_defconfig"
#####
RTL8723_BRANCH="ja/8723-update"
RTL8723_REPO="https://github.com/nextthingco/rtl8723bs"
#### 
CHIP_MALI_BRANCH="debian"
CHIP_MALI_REPO="git://github.com/nextthingco/chip-mali"

Hacking

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