Updating RPi firmware on HA Yellow with CM4

[SanjuroE]

The release notes of Home Assistant OS 18.1 came with some worrying disclaimers about possible not being able to boot after updating to 18.0 as well as something about a 'rpiboot' method on CM4:

Release Home Assistant OS 18.1 · home-assistant/operating-system

I am using a HA Yellow with CM4 running HAOS 18.1 and so far it al seems to still work. Should I be worried? Does the CM4 firmware need updating? And if so how do I use rpiboot to do so?

I found a guide on using rpiboot to re-install HAOS, but I don't want to re-install. If I need to I would just like to update the CM4 firmware.

[jacme (Jacques ARQUEY)]

I also use HA Yellow with a CM4 (Lite, no eMMC; boot and data on SSD).

I’m on HAOS 18.0, and based on the release notes, I haven’t installed 18.1.

Your post suggests it’s possible, but the need for a firmware update when using a CM4 really needs clarification.

If an update is required, I’d also like to know the procedure (setting up rpiboot seems a nightmare on the Yellow).

[Sir_Goodenough ((SG) WhatAreWeFixing.Today)]

RPi4 Bootloader Version

Yep, the github issue warns you about this in the first post: [image] Hook up a keyboard & monitor, then you should be able to check eeprom version & update from there. Step by step instructions are here.

[ShadowFist]

I think their concerns are justified in case of unsupported_boot_device error.

This is from the Core 2026.7 release notes

[ahaghshenas (Amir Haghshenas)]

Would be nice if there were some sort of walkthrough for CM4 users to update the firmware

[JorgWolski (Jorg)]

There is a revised guide on the support pages now (the Windows installer of the tool needed lacks some required files in the latest version):
https://support.nabucasa.com/hc/en-us/articles/25455063533853-Green-LED-on-Home-Assistant-Yellow-flashes-4-times-short-and-5-times-long

But it is not trivial, and as far as we know not necessary. If you don't have problems, I wouldn't recommend to do it.

[JorgWolski (Jorg)]

Update:
The Raspberry Pi Foundation changed the content of their recovery tool. Do not try a firmware update with Windows yet!
The guide will be updated when a working solution has been confirmed.

[KipiKland]

I did it through the USB attach on my Yellow with no issue. HA Yellow with CM4 and emmc + SSD. bootloader is now latest version. Did not have to remove SSD whatsoever, just made sure that boot order on ini file was correct. Attempted first through Windows WSL, but attaching USB is tricky from there, i falled back to another linux host booted Ubuntu live usb key and this worked like a charm. [edit] Windows was not reliable enough