Nico Brailovsky's thought repository

With ~most~ some of the bugs fixed in the industrial design, it's time to setup a second Homeboard. That way I can experiment on one, while the other shows pretty pictures. Because my computer is also a new install, it's now a good opportunity to document the full bootstrap process from an almost brand new and clean Ubuntu 24.04.

Bootstrap a new devenv

• Get normal dev tools sudo apt-get install build-essential git llvm vim
• The linker needs to learn how to build arm binaries: sudo apt-get install crossbuild-essential-armel crossbuild-essential-armhf
• Clone the sw project: git clone git@github.com:nicolasbrailo/homeboard.git
• Don't forget to git submodule update --init --recursive
• Type make xcompile-start in the root of gpio_mon. It will, on its first run, setup the cross-compile environment.
• The x-compile env will be "hardcoded" to some rpi image, for example 2024-11-19-raspios-bookworm-armhf.img.xz. You probably want to update ~/src/homeboard/pi_gpio_mon/rpiz-xcompile/mount_rpy_root.sh to make it point to a newer image, ideally the same one you will use to bootstrap the sd card.
• Once make xcompile-start finishes, you can check it succeeded; ~/src/xcomp-rpiz-env/mnt should contain a copy of the rpi environment (the x-compile root)

Bootstrap the OS

This article has been updated to work, but the gist of it is:

• Find the ISO you used for the x-compile env, then sudo dd of=/dev/sdX if=./XXXX.img bs=8M status=progress
• Mount the SD card and enable ssh: cd /media/$USER/bootfs && touch ssh && touch ssh.txt
• Create user (headless): echo username:password > /media/$USER/bootfs/userconf.txt
• [Wayland] Add this magic to /boot/firmware/config.txt

dtoverlay=vc4-kms-v3d
gpu_mem=128

• [More Wayland] /boot/firmware/cmdline.txt needs to have wayland=on
• Boot up with the SD card, then ssh into the device and do sudo apt-get install mesa-utils-bin wayfire seatd
• Add Wayfire as a service

Build things

• Update the TARGET_IP in the makefile, then make setup-ssh to enable passwordless ssh
• Start with the gpio_mon project, it's the simplest. cd ~/src/homeboard/pi_gpio_mon. If you make, it will either fail or create a binary in the wrong format if you haven't set up the cross-compile environment (see "bootstrap new devenv").
• After make succeeds, file gpiomon should show something like ELF 32-bit LSB pie executable, ARM, EABI5 version 1 (SYSV), dynamically linked. This means your system can now build binaries for your target platform.
• scp gpiomon $target -> try out if your xcompile env works as expected

Build harder things

• Move on to wl_display_toggle (it's the smallest project that exercises the entire stack: cross compiler and Wayfire).
• There are more system deps you'll need to install; make install_system_deps should take care of most of them.
• There are deps for the x-compile env too; make install_sysroot_deps should take care of most of them. Some deps may move around, and you may need to find newer versions.
• Now cd wl_display_toggle then make and scp wl_display_toggle $TARGET
• ssh into the target, and try to shut off the display: XDG_RUNTIME_DIR=/home/batman/run WAYLAND_DISPLAY="wayland-1" DISPLAY="" ./wl_display_toggle off

Install services

The homeboard doesn't do much nowadays, only show images; once you reached this point, and if things build and run, your build environment and target are ready to use. Just a few more arcane spells and we're done:

• Clean up binaries deployed ad-hoc, like gpio_mon and wl_display_toggle
• make deploytgt
• In the target, try out hackimg
  • Run XDG_RUNTIME_DIR=/home/batman/run WAYLAND_DISPLAY="wayland-1" DISPLAY="" /usr/lib/arm-linux-gnueabihf/ld-linux-armhf.so.3 /home/batman/homeboard/bin/hackimg /home/batman/homeboard/cfg/hackimg.cfg
  • You'll need to create the cache dir manually, because hackimg is lazy and won't do it for you
• Once you checked hackimg runs, vi ~/homeboard/cfg/pipresencemon.cfg
  • Set the sensor pin to the GPIO acting as presence sensor
  • Adapt the sensitivity to sensor type (mmwave vs PIR)
  • It's recommendable to use the mock gpio for a test run
• Try out the ambience service
• In the target, cd ~/homeboard/scripts && ./install_svc.sh - this will install the ambience service and launch it. Wayfire should already be a service by now, so no install is included.
• Use ~/homeboard/scripts/logs.sh to see what's broken.

The target should be ready for production, in only about 30 simple steps!

Appendix: it hangs!