Ubuntu 18.04.5 release for Raspberry Pi 4 does not boot

[Ryan Govostes]

I have a Raspberry Pi 4 Model B. I downloaded and flashed the image `ubuntu-18.04.5-preinstalled-server-arm64+raspi4.img` (md5 = b75105bf4e27cbcc44dc471becc8907d), which is the currently recommended release for this hardware on the Ubuntu.com website.

Booting reaches this point where it tries to do something with the SD card, then fails:

[ 4.352613] random: fast init done
[ 4.414200] mmc0: new ultra high speed DDR50 SDHC card at address aaaa
[ 4.423077] mmcblk0: mmc0:aaaa SC32G 29.7 GiB
[ 4.431244] mmc1: new high speed SDIO card at address 0001
[ 4.437267] mmcblk0: p1 p2

Afterwards, about once per minute, it outputs an error message like this:

[ 28.006460] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[ 28.012484] rcu: 1-...0: (7 ticks this GP) idle=1d6/1/0x4000000000000000 softirq=80/81 fqs=7
[ 28.021231] (detected by 3, t=5893 jiffies, g=-379, q=2)
[ 28.026710] Task dump for CPU 1:
[ 28.029984] swapper/0 R running task 0 1 0 0x0000002a
[ 28.037143] Call trace:
[ 28.039636] __switch_to+0xcc/0x208
[ 28.043179] console_unlock+0x4f8/0x600
[ 28.047076] rcu: rcu_sched kthread starved for 1001 jiffies! g-379 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=3
[ 28.057405] rcu: RCU grace-period kthread stack dump:
[ 28.062529] rcu_sched I 0 10 2 0x00000028
[ 28.068098] Call trace:
[ 28.070580] __switch_to+0xcc/0x208
[ 28.074123] __schedule+0x2c4/0x7b0
[ 28.077663] schedule+0x38/0xa8
[ 28.080851] schedule_timeout+0x1a0/0x378
[ 28.084920] rcu_gp_kthread+0x688/0xa10
[ 28.088813] kthread+0x124/0x128
[ 28.092089] ret_from_fork+0x10/0x1c

I made 2 or 3 attempts at this and each time it failed in the same way.

The only modifications I made to the filesystem were to the `user-data` and `network-config` files for headless setup. I do not believe these modifications are relevant.

I downloaded and flashed the previous release, `ubuntu-18.04.4-preinstalled-server-arm64+raspi4.img`, and that release booted successfully.

[Ryan Govostes (rgov)]

I decompressed the image again and got the md5 `3a156ce4bb81f48876e648d46a7ae6d6` but I did not try flashing it. It seems likely it was simply a broken image. I could not find a published md5 to verify. The files are the exact same number of bytes, though.

[Ryan Govostes (rgov)]

I downloaded and decompressed the image again and got `3a156ce4bb81f48876e648d46a7ae6d6` so I am more confident that this is the correct version of the image.

However, it fails the same way.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1895550/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Ryan Govostes (rgov)]

Sending to the kernel team but not sure it belongs with them.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1895550

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Ryan Govostes (rgov)]

I am unable to collect logs because the system fails to boot.

[Ryan Govostes (rgov)]

I also could not boot 20.04.1 on a Raspberry Pi 4.