[SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

simfir · 2015-07-20 14:56:52

On a somewhat older system (Core 2 Duo, 64Bit, UEFI, build around 2009, Bios is from 2011) that ran fine under Archlinux up to kernel 4.0.7-2-ARCH, the recent Arch standard kernel 4.1.2-2 won't start anymore.

The kernel selection menu of the bootloader shows up fine. After selecting the kernel it says

Error loading /vmlinuz-linux: Unsupported

and shows the menu again.

Using gummiboot, that's it. Using systemd-boot, there is an additional line telling the same in other words: It can't start that kernel (and won't tell me why exactly).

I've checked the /boot-partition using fsck.vfat. No errors came up.

I've removed and reinstalled the kernels (usb key + arch-chroot).

I went from gummiboot to systemd-boot.

The linux-grsec kernel shows this behaviour consistently since I first tried it some month ago. I believed it to be a problem specific to grsec and didn't track it down then after a quick websearch didn't turn up anything, because grsec is no serious option for that computer anyway. (Thanks to the problems with virtualbox.)

The linux-lts kernel runs fine. I could live with the lts kernel, but it is written in fiery letters to the sky that the next lts kernel will fail to boot like the others already did.
I could also live with compiling my own kernel. But for that I need to find out what goes wrong so I can do it differently.

I'd be grateful for suggestions on how to proceed from here. Thanks a lot.

Update: The second error message I've talked about above ist

Failed to execute Arch Linux (\vmlinuz-linux): Unsupported

(Not adding much info. "Arch Linux" is the name of the boot manager entry. There is a file /boot/vmlinuz-linux which is a linux kernel and I'm quite sure it is not corrupted.)

Last edited by simfir (2015-07-20 20:51:01)

clfarron4 · 2015-07-20 15:18:02

Did you try downgrading the kernel back to 4.0.7-2 and booting into it?

If that doesn't solve it, then maybe try some of the boot debugging suggestions to get more information about it

mrunion · 2015-07-20 18:12:51

Are you sure the /boot partition is mounted when you updated the Kernel? The UEFI boot partition -- not a /boot folder on the drive, but the actual one your machine is booting from on the $ESP? It sounds like you may not have the proper /boot mounted when installing a new Kernel.

simfir · 2015-07-20 18:21:19

Thank you both for your suggestions.

I am absolutely sure that the /boot partition is mounted correctly during kernel upgrade. During my last attempts the kernels linux and linux-lts were even installed in one pass. One is working, one not.

I did not try to downgrade to 4.0.7-2, because I shot myself in the foot 20 minutes before I had that idea. Somebody else has experienced that error message and reported the cause to be a corrupted kernel image. For him, reinstalling the kernel had helped. So I tried. And of course I wanted the kernel fresh from the web, so I deleted the local cache. Well, must have worked with maven repositories for too long, where you get any version ever released whenever you want. Turns out, pacman is different. A lot.
Trying out linux-lts was my replacement for downgrading to 4.0.7-2.

I tried "Insane Debugging" from your link both with the standard kernel and the lts kernel. I made sure, both get the exact same configuration in order to catch any stupid mistakes I might make compiling that super long options line.
Result: An insanely slow computer and a lot of text when booting the lts kernel. The exact same outcome as without the debug options when booting the standard kernel. Not a single additional message.

I believe there is never a single line of kernel code executed: The bootloader looks at the file and decides that this is not what it wants and prints the "Unsupported" message(s).

As I seem to be the only one far and wide who's got that problem my hypothesis is now: Got a previously dormant bug in my computers UEFI code. A recent change triggers it. That change is either in the linux kernel, the way it is built, or in the bootloader.

So I could try grub2.
I could try to compile my own kernel and see what happens.
I could go through the hassle of downgrading using ATM (to find out what I think I already know: 4.0.7-2 works).
I could simply throw away that old computer because I'm shaving a yak here and the time investment gets out of hand.

Better/more ideas anybody?

2ManyDogs · 2015-07-20 18:45:57

In one message you say the lts kernel works fine, but you think it will eventually fail. In your last message it looks like you are having problems with the lts kernel as well. I am confused. Does lts work?

Last edited by 2ManyDogs (2015-07-20 18:46:10)

simfir · 2015-07-20 19:09:55

Confusing people is my superpower...

linux-lts works fine.

I did the debugging options stuff with lts as well so I know: Seeing no effect at all is not because I'm too stupid to specify kernel boot parameters but because there is nothing to see.

Standard kernel without debugging options: fail
Standard kernel with debugging options: fail in exactly the same uninformative way
LTS kernel without debugging options: works
LTS kernel with debugging options: works and produces debugging output as expected (so I did it right)

The idea that linux-lts will eventually fail: Someday another kernel will be the new lts kernel. When this happens, whatever change causes my problems will very likely be in there.

2ManyDogs · 2015-07-20 19:22:04

^ Possibly, but in the meantime, you should be able to continue using lts for quite a while (this is why it's called "long-term stable" :-) And while this is not really recommended, you can also put the lts kernel on hold so it never gets updated.

simfir wrote:

The idea that linux-lts will eventually fail: Someday another kernel will be the new lts kernel. When this happens, whatever change causes my problems will very likely be in there.

You don't know this for sure -- maybe whatever is causing the problem will be fixed. And now that you have learned not to delete your package cache, you will be able to roll back to a good working kernel even if the next lts does break.

If you want to continue to troubleshoot this, you could look the the config files for the working lts kernel and the non-working 4.1 kernel (I like vimdiff for this) and try to figure out what changed.

Last edited by 2ManyDogs (2015-07-20 19:31:12)

simfir · 2015-07-20 20:36:27

I couldn't let go and replaced systemd-boot with grub. And behold: Grub is able to boot the problematic kernels, even linux-grsec.

Conclusion:

The problem is not understood, but there is a workaround that is ok for me as a solution: Use grub instead of systemd-boot/gummiboot.
While it might be related to some systemd-boot bug, it is more likely a problem of the computers UEFI code.
There is no community value in chasing this down further because it is not widespread and will vanish with the mainboards of this batch.
If somebody else runs into this and cannot live with grub, comparing the configuration of Arch kernels 4.0.7-2 and 4.1.2-2 might be a good start.

Thank you very much to everybody who invested time in thinking about my problem and maybe has even written an answer!

(Now if I could find out how to set this to "solved"... probably the moderators job around here?)
(Update: Found out. Just editing the first post. Too easy to be obvious.)

Last edited by simfir (2015-07-20 20:50:12)

thestinger · 2015-07-29 01:19:52

grub will probably break when they move to the modern UEFI boot path.

simfir · 2015-07-29 14:29:10

Thanks for the warning.

Arch Linux

#1 2015-07-20 14:56:52

[SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

#2 2015-07-20 15:18:02

Re: [SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

#3 2015-07-20 18:12:51

Re: [SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

#4 2015-07-20 18:21:19

Re: [SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

#5 2015-07-20 18:45:57

Re: [SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

#6 2015-07-20 19:09:55

Re: [SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

#7 2015-07-20 19:22:04

Re: [SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

#8 2015-07-20 20:36:27

Re: [SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

#9 2015-07-29 01:19:52

Re: [SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

#10 2015-07-29 14:29:10

Re: [SOLVED] Kernel update: "Error loading /vmlinuz-linux: Unsupported"

Board footer