Got a little bit further.
The rpi5 has been configured into its firmware via a debian variant
to try usb booting first.
I was able to use the rpi probe from a linux machine using
"picocom --quiet --baud 115200 /dev/ttyACM0" into the rpi5.
Installed OpenBSD from the sdmmc to an external ssd which shows up as
sd1. This appeared to proceed fine.
Removing the sdmmc and rebooting gets it to the UBoot> prompt
where it's unable to proceed further. Seems that the stuff handing over uboot
to openbsd might not be there? I don't know. It sees the uboot but thinks
it's still mmc even with it removed.
U-Boot 2025.07 (Mar 02 2026 - 10:13:27 -0700)
DRAM: 1020 MiB (total 16 GiB)
RPI 5 Model B (0xe04171)
Core: 25 devices, 11 uclasses, devicetree: board
MMC: mmc@fff000: 0, mmc@1100000: 1
Loading Environment from FAT... Card did not respond to voltage select! : -110
** Bad device specification mmc 0 **
In: serial,usbkbd
Out: serial,vidconsole
Err: serial,vidconsole
Net: No ethernet found.
starting USB...
No USB controllers found
scanning usb for storage devices... 0 Storage Device(s) found
Hit any key to stop autoboot: 0
Card did not respond to voltage select! : -110
Cannot persist EFI variables without system partition
Card did not respond to voltage select! : -110
U-Boot> setenv bootdelay -2
U-Boot> boot
Card did not respond to voltage select! : -110
U-Boot> run findfdt
## Error: "findfdt" not defined
U-Boot> findfdt
Unknown command 'findfdt' - try 'help'
U-Boot>
saveenv throws an error where it can't write to mmc
Here's what happens when the sdmmc boots:
starting USB...
No USB controllers found
scanning usb for storage devices... 0 Storage Device(s) found
Cannot persist EFI variables without system partition
** Booting bootflow '<NULL>' with efi_mgr
Booting: Label: mmc 0 Device path:
/VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b,0000000000000000)/VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b,6d00000001000000)/SD(0)/SD(0)
disks: sd0*
>> OpenBSD/arm64 BOOTAA64 1.24
boot>
I don't know how the Label: path would be derived for sd0. How to make this
machine boot off installed
usb3 media?
thanks,
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