This Docker image is meant to be used to build a Linux Kernel for the Raspberry Pi with TPM support (especially LetsTrusts TPM). The steps involved have been extracted from:

letstrust.de - Howto Enable TPM Support on a Raspberry PI (0, 0W, 1, 2, 3, 3b+) and make it work with the LetsTrust TPM

This projects aims to enhance already running Raspberry Pis with TPM. Hence, this Docker container expects two volume mounts:

lsblk -o NAME,FSTYPE,LABEL,MOUNTPOINT /dev/mmcblk0
NAME        FSTYPE LABEL  MOUNTPOINT
mmcblk0                   
├─mmcblk0p1 vfat   boot   /media/user/boot
└─mmcblk0p2 ext4   root   /media/user/root

This is how a typical Raspberry Pi SD card is formatted while following the standard installation instructions. If your SD card is still empty, prepare your SD card following those instructions first.

Build the Docker image:

sudo docker build -t rpi_tpm_kernel_builder .

Afterwards adapt the paths to which your system has mounted the SD card partitions (you can find them using lsblk for example):

SDCARD_BOOT_PATH=/media/user/boot
SDCARD_ROOT_PATH=/media/user/root

and run:

sudo docker run -it --volume $SDCARD_BOOT_PATH:/media/boot --volume $SDCARD_ROOT_PATH:/media/root rpi_tpm_kernel_builder

to build and deploy the kernel to the SD card.

It is possible to change the Kernel version. This is possible using the Docker's build argument KERNEL_BRANCH, for example:

sudo docker build --build-arg KERNEL_BRANCH=rpi-4.16.y -t rpi_tpm_kernel_builder_rpi-4.16.y .

will build a Kernel with version 4.16. Any branch from Raspberry Pi's Linux Kernel repository can theoretically be used, but newer versions can introduce new dependencies which this Docker container doesn't fulfill.

It is possible to switch between "Pi 2, Pi 3, or Compute Module 3 (default)" and "Pi 1, Pi Zero, Pi Zero W, or Compute Module". To switch to a build for a Pi Zero, use the KERNEL build argument:

sudo docker build --build-arg KERNEL=kernel -t rpi_tpm_kernel_builder_rpi_0 .

The last tested kernel version can be found using the git tags of this repository.