Building kernel module for hikey running debian (4.19.5-hikey - developer)

[Achyut_Hegde]

Hello everyone,

I would like to build a custom kernel module for the debian that is running on my hikey960 board.
For this I would need kernel headers of the OS. What is the right option.

1. Download the headers externally and cross-compile on a build server.
2. Build the kernel module on the hikey device itself.
   Is there any detailed link for building modules?

Thanks, Achyut

[leo-yan]

Hi,

@Achyut_Hegde

Build the kernel module on the hikey device itself.
Is there any detailed link for building modules?

You could refer to below thread for the detailed steps:

Custom kernel build doesn't load modules when booting

So your kernel is not aligned with modules, your kernel has been built with 4.14.96.01198-gc6a40c56e419 version magic and modules with 4.14.96.01198-gc6a40c56e419-01198-gc6a40c56e419 (which seems wrong). You can find below the script I use to build kernel/modules: #!/bin/sh # Usage: ./build-kernel.sh [kernel-src] [release] set -e KERNEL_SRC=${1:-./} cd ${KERNEL_SRC} CONFIG="distro.config" RELEASE=${2:-"4.14.0-qcomlt-arm64"} export ARCH=arm64 export CROSS_COMPILE=${CROSS_COMPILE:-aarch64-lin…

[Achyut_Hegde]

@leo-yan Thank you for the link. I will try to follow along similar lines for hikey960.

Do you/anyone knows if we can build standalone module for the kernel headers and just copy them to hikey and load manually? It would be convienient to just build a module and use.
To put it other ways, Does hikey build system mandates to load the module during the boot?

Thanks,
Achyut

[Loic]

I would suggest to git clone the hikey960 tree and checkout the correct commit/tag to be aligned with your running kernel. Then build the kernel and module(s) you’re interested in and push it on your board via e.g. ssh. You should be able to load it manually with insmod.You may want to copy the module(s) under the standard path (/lib/modules/$(uname -r)/kernel) and run depmod to regenerate dependencies…

[Achyut_Hegde]

@Loic Thanks for the suggestion. I was looking for something faster.

I followed the steps from this page below and was able to successfully build and load kernel modules.

OpenCL support on Debian/hikey960

Next step I would like to build my own kernel images. The basic need is to update device tree to suit my needs. I downloaded rootfs and boot files from the link below:
http://snapshots.linaro.org/96boards/hikey/linaro/debian/latest/

Do you/anyone knows where I can find corresponding source code for kernel and steps to build images on our own.

Thanks,
Achyut