Kernel panic after Systemupdate (pacman -Syu)

[pepedog]

Kmihelich has now made a special change to pacman, sync is run on completion of any writes.
sync still needed for other occasions.

[StaticMove]

Hi guys,

I had exactly the same problem after the last 2 system updates with pacman -Syu where kernel update was involved. At first I thought it was a SD card problem (corrupted filesystem or something similar), so I bought a new one. But the problem took exactly the same shape:

After unpacking the ArchLinuxARM-2014.04-rpi.img the Pi worked flawlessly with the kernel included in the image (sorry, do not remember the version). But after the upgrade to 3.10.37-1 or higher the Pi had the same symptoms as linarmux describes. The same happens even with the raspberry-pi-latest kernel branch.

Since there is no Arch Rollback Machine for ARM archlinux, I was not able to test the latest working kernel version. However I found a temporary workaround because I needed my Pi working. If I take any of the above mentioned kernels (3.10.37-1, 3.10.38-1, 3.14.1-2 or 3.14.2-1) from the arm directory instead from the armv6h and manually extract them, the Pi boots with no problem with any of those.

At this time I am running manually extracted arm (not armv6h) 3.10.38-1 kernel and entered linux-raspberrypi into the /etc/pacman.conf IgnorePkg section not to mess the system accidentally with new system update again.

Got a spare SD card for experimenting and testing so if I could be helpful anyhow please let me know.

Cheers

[WarheadsSE]

http://www.adminempire.com/arch-linux-a ... k-machine/

[StaticMove]

Hi WarheadsSE,

my bad, sorry. Thanks for the link. I will do the testing and let you know which version of the armv6h is the last one working by me.

And when I am in the testing, I will post the exact error message I got because when I studied linarmux's pictures in detail, his problem was missing init, which was not mine for sure. Just the symptoms.

Thanks again, will report back

[StaticMove]

Hi WarheadsSE,

after extensive testing with 2 different SD cards and 6 versions of the kernel from the rollback machine I am starting to suspect my RPi SD card slot.

When installing the different kernel versions with pacman, sometimes the kernel was totally unbootable (stuck at the coloured splashscreen), sometimes I got kernel panic errors like "Unable to handle kernel NULL pointer dereference at virtual address xxxxxx" or "Alignment trap", sometimes the Pi booted fine.

When I got any of the problems mentioned above, the simple solution was to manually copy the kernel.img from the right linux-raspberrypi archive in /var/cache/pacman/pkg to /boot partition and everything was OK. I have to remark that I always did fsck on both SD card partitions (the filesystem was always clean) and trying to copy the pacman "created" kernel.img with appropriate modules directory to different location to test if it was readable was always successful too.

But since all the fsck, reading and most importantly manual copying of the kernel.img from the archive to /boot partition was made on a Linux desktop computer (which means different SD card slot) and I was using 2 different SD cards (and both behaved the same), I think the problem has to be in the Pi.

Sorry to bother you and thanks for pointing me the right direction with the ARM rollback machine.

Cheers

[jass0]

If it's still the same filesystem, I'd rather suspect you have some "partially" installed packages and your filesystem is somewhat busted.

You could try reinstalling all the packages that we're updated before you got the kernel panic. You should be able to see all the updated packages by listing the contents of the pacman package cache:
$this->bbcode_second_pass_code('', 'ls /var/cache/pacman/pkg/ -tr --full-time')

Or you could just reinstall all packages.

Sync afterwards.

[StaticMove]

Hi Jass,

thanks for your advices.

It really looks like the SD card slot was to blame for the problem. I cleaned all the pins with contact cleaner, bend them a little as advised on http://elinux.org/R-Pi_Troubleshooting and no problems updating any package since then.

And to be absolutely sure, I carried out a clean Arch install. Did not want to risk any messed up packages or filesystem.

Thanks again