Download the UEFI bios v 1.20 and unzip the files to a
FAT-formated microSD card. You can leave other files on
the card, like your music.
Get the zip via https from
github.com/pftf/RPi4/releases/download/v1.20/RPi4_UEFI_Firmware_v1.20.zip
The zip file contains
RPI_EFI.fd
Readme.md
bcm2711-rpi-4-b.dtb
config.txt
fixup4.dat
overlays/miniuart-bt.dtbo
start4.elf
The RPI4 uses RPI_EFI.fd as a pseudo-NVRAM. Any changes to the
BIOS are recorded there.
Insert microSD card into RPI4B, switch on HDMI monitor, add USB
keyboard and power on.
After the multi-colour RPI4B display, an outline Raspberry logo
appears, after about 60 seconds an (invisible) network boot
process will fail and a BIOS-like user interface appears.
Use the keyboard to select these under Device Manager / Raspberry
Pi Configuration:
Advanced Configuration, change Limit RAM to 3GB to disabled
SD/MMC Configuration, change uSD/eMMC Routing from Arasan
to eMMC2 SDHI
Plug in a USB3 disk (I use a Kingston 120GB sata SSD and
Orico USB3 to sata adapter) to another OpenBSD box, and
ftp https://cdn.openbsd.org/pub/OpenBSD/snapshots/arm64/miniroot68.img
dd if=miniroot68.img of=/dev/rsd1c bs=1m
then move the USB3 disk to a blue connector on the RPI4B, then
Reset the RPI4B using the keyboard. After about a minute,
after network boots have failed, the OpenBSD Installer will appear.
Configure OpenBSD with your USB keyboard. The wifi won't
work (bwfm(4)). The wired Ethernet is bse(4).
Before rebooting the installation, select Shell and enter
echo set tty fb0 > /etc/boot.conf
then reboot.
The syspatch utility will work to update your -current install.
John
