Bookworm armhf cross compile kernel docker
From embeddedTS Manuals
To compile the kernel you should use the Debian cross compile docker from a linux workstation.
We can use a shell script to enter the docker, and compile the kernel into a tar that can be distributed to the board. For example:
mkdir ~/Projects/kernel-5.10/
cd ~/Projects/kernel-5.10/
git clone https://github.com/embeddedTS/linux-lts.git -b linux-5.10.y linux
Make a ~/Projects/kernel-5.10/build.sh with:
#!/bin/bash -e
if [ ! -e "/.dockerenv" ]; then
exec docker-debian-bookworm "$0 $@";
fi
export ARCH=arm
export CROSS_COMPILE="arm-linux-gnueabihf-"
export LOADADDR=0x10008000
cd linux
if [ "$#" != "0" ]; then
"$@"
exit 0;
fi
## Make any changes in "make menuconfig" or driver modifications, then compile
make -j"$(nproc --all)" all uImage
# Install to a temporary directory
TEMPDIR=$(mktemp -d)
export TEMPDIR
mkdir "$TEMPDIR"/boot/
cp arch/arm/boot/uImage "$TEMPDIR"/boot/uImage
cp arch/arm/boot/zImage "$TEMPDIR"/boot/zImage
cp arch/arm/boot/dts/imx6*-ts*.dtb "$TEMPDIR"/boot/
INSTALL_MOD_PATH="${TEMPDIR}/usr/" make modules_install
cd ../
fakeroot sh -c "chmod 755 $TEMPDIR;
chown -R root:root $TEMPDIR;
tar cjf kernel.tar.bz2 -C $TEMPDIR .;
rm -rf $TEMPDIR";
Make this executable:
chmod a+x ~/Projects/kernel-5.10/build.sh
The kernel can be compiled by running these two commands:
./build.sh make ts_defconfig
./build.sh # No arguments runs the build and packages the kernel
# This will output the build in the current directory as kernel.tar.bz2
Any arguments to this script will be executed in the linux path. For example:
./build.sh make ts_defconfig
# Customize the kernel config
./build.sh make menuconfig
# Test a compile (does not package the install)
./build.sh make
# Get a shell prompt in the kernel sources to run commands manually:
./build.sh bash
The kernel.tar.bz2 from this build script can be extracted from a board, or over an image to install this kernel. For example, copy this to the SBC and run:
tar -xhf kernel.tar.bz2 -C /
From a workstation this can similarly be used to install over a mounted SD image:
sudo mount /dev/sdc1 /mnt/sd/
sudo tar -xhf kernel.tar.bz2 -C /mnt/sd/
sudo umount /mnt/sd/