Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.


Customizing Linux Kernel for IMX6Q with Yocto Project
=====================================================

This repo is based on i.MX Linux 5.15.71_2.2.0 released Dec 2022. Follow
these steps to compile the customized kernel for your project.

1- Setup Yocto project for for your i.MX device using "i.MX Yocto Project 
   User's Guide (Rev. LF5.15.71_2.2.0)" upto step#5.1 in the guide. This 
   downloads all the layers that you may need to compile an embedded linux 
   image for your i.MX device.
2- Fork the linux-imx repo maintained by nxp: 
   https://github.com/nxp-imx/linux-imx and checkout the commit
   "3313732e9984cb8a6b10a9085c7e18d58e770d56" which corresponds to 
   i.MX Linux 5.15.71_2.2.0 (Kirkstone). Now, you can make the desired 
   changes to the project.
3- Yocto project contains several layers with components from various
   sources that will be compiled into the final image. The base linux 
   kernel with i.MX related drivers is compiled by the meta-imx/meta-bsp
   layer. The corresponding recipe file is found at: <parent directory>/
   sources/meta-imx/meta-bsp/recipes-kernel/linux/linx-imx_5.15.bb . 
   Locate this file.
4- The "KERNEL_SRC" variable (at line number 21) points to the linux-imx
   repository that will be used to download and compile the base linux 
   kernel for i.MX machine. Modify it to point to your forked repository.
5- The "SRCREV" variable (at line number 25) contains the commit ID that
    will be checked out before the project is compiled. Replace it with 
    the commit ID that refers to your changes.
6- Compile the kernel using the following command: 
   MACHINE=imx6qsabresd bitbake linux-imx . You can replace the MACHINE
   name with your own boards name. If successful your project will now 
   build with the customized linux kernel.
7- You can continue to build the complete image by following steps 5.2 
   and onwards in the "i.MX Yocto Project User's Guide 
   (Rev. LF5.15.71_2.2.0)"