OpenHD-Image-Builder

• 1. Flashing
• 2. What is this
• 3. Using
• 4. More information (what’s going on?)
  • 4.1. STAGES
    • 4.1.1. Skipping
    • 4.1.2. Scripts
    • 4.1.3. Small
• Contributing

1. Flashing

When flashing please use the OpenHD-ImageWriter. If you want to flash the Images manually you need to create a (air.txt) or (ground.txt) file in the openhd folder, which is in the root of the FAT32 Partition on the SD-CARD.

2. What is this

This project takes a base image and modifies it into an OpenHD compatible image. For the long version, read on.

3. Using

In order to be able to run this you need a Debian or Ubuntu Linux machine with 30 Gb free space on the main partition, and with the following packages:

sudo apt install unzip curl git qemu qemu-user-static binfmt-support build-essential gcc-arm*

If any of the packages fails to install, run apt update prior to the apt install command:

sudo apt update

Then git clone this repository to a suitable folder

git clone https://github.com/OpenHD/OpenHD-ImageBuilder.git
cd OpenHD-ImageBuilder

Elevate your prompt:

sudo -s

And run:

./build.sh TARGET

or

valid targets are:

pi-bullseye
x86-lunar
rock5b
rock5a
radxa-cm3
x20
radxa-zero3w

4. More information (what’s going on?)

Note: if a build fails for some reason, be sure to run the cleanup script so that any temporarily mounted images are cleaned up:

./clean-fail.sh

4.1. STAGES

The core concept (and some code) was taken from pi-gen, the Raspbian image generator.

Whenever we make a OpenHD image, we basically perform several steps in order:

• Step 01-00 Download a base image

• Step 01-01 Increase the size of the root partition if necessary

• Step 02-00 Install,Remove,Hold Packages (gets documentation soon)

• Step 03-00 Misc changes to the image, copying files, setting usernames,…​

• Step 03-01 Enable/Disable Services

• Step 03-02 Additional changes for device detection (poc)

• Cleanup

The ImageBuilder allows us to run the build process once, and when we want to make a change in stage 3, we only run stage 3 and 4 again by removing the SKIP file from the stages/03-Packages and the stages/04-Wifibroadcast folders. The build system will copy the kernel IMAGE.img from stage 2 to stage 3 and re-run all the scripts in stage 3. The resulting image is copied to stage 4 and all those scripts are run. Finally, when there are no more stages, the IMAGE.img from the last stage is copied to the ./deploy directory and renamed to include the target board and OpenHD version.

4.1.1. Skipping

By placing a SKIP file in the stage folder, the entire stage will be skipped by the build system. Please be aware there is no sanity check in place, removing the SKIP file from stage 3 while leaving the SKIP file in stage 4 will produce an image based on the previous run, ignoring the modifications done in step 3.

It is also possible to put a SKIP-IMAGE file into a stage, this will disable any attempt to copy the image from the previous stage. This is mainly used to prevent image copying in stage 00 and 01 where no image is yet available.

4.1.2. Scripts

Every stage comprises one or more scripts. Scripts need to be named in the format XX-run.sh or XX-run-chroot.sh. The order is determined by the XX part, where any -chroot script is run AFTER the non-chroot script.

chroot? What’s that? Well, it’s a little complex, but basically it allows you to run statements within the image as if you were running the image on an actual target board like the Raspberry Pi. This is used to download and install the apt-get packages and several scripts to make the image ready for use with the OpenHD system. Please remember to use sudo in the -chroot scripts where approperiate.

4.1.3. Small

We’ve added a small option, which removes the old images after each step is done.

Contributing

Thanks to all the people who already contributed!