Skip to content

Home

Jump to bottom
Sathyanarayanan Kuppuswamy Natarajan edited this page Apr 30, 2017 · 22 revisions

Welcome to the kdev wiki!

Introduction

Kdev is a python based Linux kernel build script. You can use this script to build kernel and rootfs image for a supported target platform. It also has support for creating kernel image in both efi and bootimage format.

Enviroment setup

Get kdev repo

git clone --recursive https://github.com/knsathya/kdev.git
cd kdev
ln -s [path to your kernel] kernel

Library requirements

python > 2.7
pip install -r scripts/requirements.txt

How to build

First set your environment by sourcing scripts/setenv.sh

source scripts/setenv.sh

You can build kdev image(rootfs + bzImage) by executing the build.py. Before you run this script you should make sure you have valid "kernel" project checked out out in the current directory.

python build.py

Once you run this script, it will parse the target-recipes folder and will display the list of valid build targets and request user to select the build target. You can also skip this selection by setting the following environment variable.

export SELECTED_TARGET_DIR=target-recipes/<soc>/<board>/

To get more info on various options of build.py,

python build.py -h

usage: build.py [-h] [-k KERNEL_DIR] [-r ROOTFS_DIR] [-o OUT_DIR]
                [-t RECIPE_DIR] [--build-efi] [--skip-build-rootfs] [--log]
                [-v]

kdev build app

optional arguments:
  -h, --help            show this help message and exit
  -k KERNEL_DIR, --kernel-dir KERNEL_DIR
                        kernel source directory
  -r ROOTFS_DIR, --rootfs-dir ROOTFS_DIR
                        rootfs directory
  -o OUT_DIR, --out-dir OUT_DIR
                        out directory
  -t RECIPE_DIR, --target-recipe RECIPE_DIR
                        target recipe directory
  --build-efi           Build efi image
  --skip-build-rootfs   skip building rootfs
  --log                 logs to file
  -v, --version         show program's version number and exit

After successfully running this script, it will generate the kdev images in the "out" folder. For example, for bxt_joule_pr0, you can find images under,

out/bxt_joule_pr0/images

Following are the list of out dir content.

  • images/bzImage.efi - kernel image with EFI stub.
  • kernel-obj - obj directory for kernel.
  • rootfs - copy of rootfs.
  • images/rootfs.img - cpio.gz format of rootfs image.
  • images/rootfs.img.ext2 - rootfs image in ext2 format.

How to add a new target recipe

To create a new target recipe, create a separate target folder under "target-recipes" in the following format.

mkdir target-recipes/<soc>/<board>

Each target recipe should contain following files. If one of this file is missing, then it will not be considered as a valid target.

board.cfg - config file to specify board params
cmdline - kernel command line parameters
kernel.config - Target kernel config

Following is the board.cfg format.

[board_options]
arch = x86_64
soc = bxt 
board = joule
version = pr0 
target_name = ${soc}_${board}_${version}

[build_options]
build_efi = true
build_bootimg = true
build_yocto = true
kernel_config = ./kernel.config
kernel_diffconfig =
cmdline = ./cmdline

[rootfs_options]
use_initramfs = false
rootfs_name = busybox
gen_cpioimage = true
gen_hdimage = true

[bootimg_options]
base = 0x10000000
kernel_offset = 0x00008000
ramdisk_offset = 0x01000000
second_offset =
os_version = "v1.0"
os_patch_level = "1" 
tags_offset =
pagesize = 4096
use_id = false

Config parameter info

Following are the main sections of board config file.

  • board_options - It contains options for configuring the board name, soc and arch type
  • build_options - It contains options for building kernel and rootfs. Like, kernel config file, cmdline, rootfs type and build image format types for different OSes.
  • rootfs_options - It contains options to configure rootfs type and image formats.

Along with above sections, we have following optional sections.

  • bootimg_options

Clone this wiki locally