OpenBSD 6.8 on RaspberryPi 4 B

The following notes capture the process I followed to get OpenBSD 6.8 running on a Raspberry Pi 4 (8GB). There is working X11 support (without hardware acceleration) on top of the framebuffer and the framebuffer console does work via HDMI with the latest EEPROM and UEFI as per below.

Supposedly it's possible to boot directly from usb without needing an sdcard for the UEFI but I have not had success with that yet.

Update: As of 4/17/2021, there has been some cleanup and improvements to the Raspberry Pi 4 boot process on OpenBSD 6.9 without requiring all the extra steps involving UEFI firmware, see more details below:

https://marc.info/?l=openbsd-cvs&m=161869438709739&w=2

https://marc.info/?l=openbsd-cvs&m=161869450909798&w=2

Update EEPROM via Raspberry Pi OS

1. Boot Raspberry Pi OS on an sdcard
2. Run updates:

apt update && apt upgrade -y

rpi-eeprom-update

Load the latest UEFI onto an sdcard (or USB drive)

Follow these steps: https://github.com/pftf/RPi4#installation

2021-04-11 Update:

• Release v1.21 is confirmed working: https://github.com/pftf/RPi4/releases/tag/v1.21
• v1.25 is currently broken: details on reddit thread
• v1.22 - v1.24: I have not tested yet.

Set UEFI settings for OpenBSD compatability

• Boot with hdmi monitor and keyboard attached
• Press ESC to enter UEFI settings
• Device Manager -> Raspberry Pi Configuration -> Advanced Configuration ->
  • Limit RAM to 3 GB: Disabled
  • System Table Selection: Devicetree
• Device Manager -> Raspberry Pi Configuration -> SD/MMC Configuration ->
  • uSD/eMMC Routing: eMMC2 SDHCI

Save the above with F10 and Reset from the main UEFI menu.

You can also try to set the boot order to have your USB drive first but I found that this setting would never actually save and take effect upon a reboot.

Install OpenBSD

• Read the docs: https://www.openbsd.org/arm64.html
• And more docs: https://ftp.openbsd.org/pub/OpenBSD/6.8/arm64/INSTALL.arm64 (In particular the section: 'Install on Raspberry Pi 4:')

Load miniroot onto a usb drive

# from an OpenBSD machine
dd if=miniroot68.img of=/dev/rsdXc bs=1m status=progress

# Or from a linux machine
dd if=miniroot68.img of=/dev/sdX bs=1M status=progress

Boot the OpenBSD installer (serial console NOT required)

• Boot with hdmi monitor and keyboard attached
• Press ESC to enter UEFI settings
• Boot Manager -> Select your USB drive and press ENTER
• OpenBSD bootloader should start: 'OpenBSD/arm64 BOOTAA64 1.3'
  • QUICKLY Interrupt it with a letter keypress 'asdf etc'
  • Backspace whatever you typed
• Set the tty to use the framebuffer instead of the serial port:
  • set tty fb0
  • Thanks Christopher Solskogen: https://marc.info/?l=openbsd-arm&m=160683302013161&w=2
• Now do a normal OpenBSD install (over the top of the same USB drive if desired).
  • Wifi firmware is missing from the installer so this is easiest with ethernet plugged in for the install. Wifi firmware is automatically installed on first boot if ethernet is available.
• Set framebuffer as default console (as per Christopher Solskogen's note)
  • echo "set tty fb0" >> /etc/boot.conf
• Enable X11
  • rcctl enable xenodm