RPI 400 Ubuntu mate 20.04.1-desktop-arm64 , instant power down

I'm trying to install Ubuntu Mate 20.04.1 but my Raspberry Pi 400 keeps shutting down before it even boots. Raspbian and Ubuntu Mate 20.10 boot fine otherwise.

Any ideas? There's no signal on monitor and it seems to be powered off since no leds are powered on and can't even numlock/caps lock.

Hi iokaravas,

I see there was no response to your question in nearly a year. Were you ever able to resolve it?

I am seeing exactly the same thing on my Pi 400. I can boot Raspberry Pi OS fine, both 32-bit and the 64-bit beta, and UbuntuMATE 20.10, 32-bit and 64-bit. Ubuntu Server 20.04 64-bit also boots fine.

UbuntuMATE 20.04 gives me the behaviour you describe, with both the 32-bit and 64-bit versions. I have tried a number of different screens so I don't think it's an HDMI issue. Similarly, I have used several different SD cards, all of which have been tested with other OSes.

Since 20.10 is no longer supported by updates, this leaves those of us who want to use UbuntuMATE with a problem until 21.04 comes out. And we won't have an LTS release until 22.04 (probably not until this time next year).

Since I'm happy with 20.04 on my other machine (x86-64), and since 20.04 is supported until April 2023, I would very much like to get the 20.04 version for the Pi 4/400 working. It seems strange that we cannot, and that this issue has received no attention.

BTW I updated the Pi 400 eeprom firmware to the current version and that made no difference to the boot failure.

Best regards.

Hi there bwindrim,

Unfortunately no...I gave up trying :frowning:

I could give it another go but I doubt anything changed if you're still having issues.

Let's hope this gets a little more attention now...

Kind regards

Hi iokaravas,

thanks for the quick reply! Sorry to hear you couldn't get further, but we can only hope...

Incidentally I was never able to run 20.04 32-bit on my Pi 2B either, though the behaviour wasn't quite the same (the 2B was supposed to be supported, though not recommended).

Best regards.

@iokaravas and @bwindrim, I also saw the exact same thing on a Pi 400.

However, I also seem to have found a workaround, although it does require extra hardware:

I moved the microSD card to a Pi 4 (along with the monitor cable, etc. that were on the Pi 400), and did a boot, and let Ubuntu Mate finish the installation.

Note that after Ubuntu Mate (mostly) finishes the installation, it gets stuck at a window that says:

Applying changes
Waiting for unattented-upgr to exit

After 10 minutes, I hit Cancel. There was additional text suggesting that an apt update was finishing, so perhaps one needs to wait for hours instead of tens of minutes for this step to properly finish.

Regardless, after it booted on the Pi 4 to the desktop, I then shut down the system and moved the microSD card and cables back to the Pi 400. This time, the Pi 400 appears to boot Ubuntu Mate as hoped/expected.

That's interesting! I do not have a Pi4 to try this on :frowning:
I wonder, does Ubuntu Mate change the partition somehow during the installation? What happens on Pi 400 seems like a really...early failure to me. It certainly didn't seem like an installation issue. Could it be that the initial setup of the SD is not agreeing with the Pi 400?

I did some more investigation, and it looks like the install process that happens during the first successful boot (using a RPi 4) does a massive rewrite of files using updated files that it downloads. Just about every file (except config.txt) in the system-boot partition gets re-written to something newer.

Whatever comes with the RPi Ubuntu Mate image file is seemingly too dated to work with the RPi 400, but yet better (RPi 400 compatible) files are available on Ubuntu Mate update servers.

So, if there is someone from Ubuntu Mate actually reading messages on this forum, please consider updating the RPi image file to use newer system-boot files.

P.S.: prior to realizing the files changed, I tried looked for log messages on the RPi 400 on the serial UART available via the 40-pin connector in the hopes of seeing why it was turning off. This was a bust, as there is absolutely no UART activity of any kind.

Hi @pinaz,

that's very interesting, thanks for the investigation and info and apologies for my delay in getting back.

I don't have access to a Pi4 either, so I can't try this at the moment, but I would still really like to get 20.04 working on by Pi400. I've just checked the available downloads and the 64-bit Pi download is still 20.04.1, even though the webpage mentions 20.04.3, which suggests that the Pi image is long overdue for a refresh.

Regarding the serial port messages; I was recently trying to disable these on a Pi2 running Ubuntu Server and it seems that - in that setup - the earliest text sent to the serial port during boot is sent by UBoot, prior to booting the Linux kernel. I'm not sure if UbuntuMate also uses UBoot (Raspbios doesn't) but if it does then it suggests that the boot sequence on Pi400 fails before UBoot gets to run.

On Ubuntu Server, the UBoot binary is named according to the machine type, so it could be that the 20.04.1 image simply doesn't contain a UBoot of the correct name. Or I could be completely off-track - I'm writing this before doing any investigation but I'll look into it now.

I looked at the firmware partition of a 20.10 SD card and it seems that UbuntuMate does use UBoot, as there are several binaries present. Notably, 20.10 has an additional one - named uboot_rpi_arm64.bin - which is not present in 20.04.1

I did try copying the 20.10 UBoot binaries to my 20.04 card but that didn't appear to make any difference to the booting behaviour we have been seeing.

It looks like I'll be waiting either for an updated 20.04 image or for 22.04 before I can use UbuntuMATE on my Pi400 as the non-LTS releases are too much of a moving target. 20.10 is unsupported already!

I just ran into this exact same issue. I also noticed the image was out of date and it would be good if it got a rebuild. Wanting to run on a Pi 400 seems to force the use of the 21.10 image at the moment. Looking forward to the new LTS being not too far away but still its not even got a beta on arm64 for MATE yet, so were still stuck in limbo here.

EDIT: This is proving to be a major pain, a bunch of software I want to use is not built for 21.10, so I'm forced to do WAY more work due to 21.10 when if 20.4 had been rebuilt it would have just worked out of the box for me.