UC20 Kernel Version

Hi kernel team,

Just had a quick chat with Ian here, https://github.com/snapcore/snapd/pull/10902. We’d like to add a snap of which functions will be included in the kernel of >5.6. Now UC20’s kernel is 5.4. Could you please upgrade the kernel to >5.6 for UC20?


Hi there, any thoughts on the kernal release plan? :slight_smile:

Ubuntu Core is tied to the LTS and only the release kernels are supported … if you have a brand store one option would be to maintain your own 5.6 kernel or alternatively buy enablement from canonical for a 5.6 backport:

Thanks @ogra for the helpful hints. Where can I find the default kernel parameters used by pc-kernel snap? Is it https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/tree/snapcraft.yaml?


The official kernels are re-packs of the binary debs, there is not actually anything built from source (snapcraft does not have access to the signing keys for secure boot so the already signed binaries from the deb are re-used) … the linked snapcraft.yaml above is for rolling your own, non-secure-boot kernels locally using snapcraft …

the actual kernel config of the deb packages is generated during build from scripts, the easiest is probably to just download the respective linux-image-generic-* deb, unpack it and there should be the generated config-* in boot/.

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I think probably I can give this a try, https://ubuntu.com/core/docs/kernel-building. A bit curious on “non-secure-boot”, can I do a self-signed key and use it for secure boot?

@ogra this post is from 2017, https://ubuntu.com/blog/how-to-sign-things-for-secure-boot, not sure if it is still being recommended to use for self-signed secure boot :slight_smile: thanks

I don’t think you mentioned with platform you are on, but if it’s intel there is a new-ish kernel snap available called intel-kernel that is based on the linux-oem-20.04 packages. That could be enough for your needs in this case.

Cheers, Just

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Thanks @jocado for the update! I didn’t find it on snap store. Do you have the link of intel-kernel project? Would like to take a look into the differences between pc-kernel and intel-kernel.


That’s not quite right, intel-kernel snap is not based on linux-oem-20.04. It is another optimised kernel specially for Intel’s Tiger Lake and Elkhart Lake IoT platforms. Please see https://ubuntu.com/download/iot/intel-iotg. It’s mostly based on the generic Ubuntu kernels with added Intel’s IoT features.

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That’s not quite right, intel-kernel snap is not based on linux-oem-20.04. It is another optimised kernel specially for Intel’s Tiger Lake and Elkhart Lake IoT platforms. Please see

In that case I stand corrected. I think I was told it was at some point.

I had initially assumed it too because normally the snaps are based on upstream debs, and the version number schemes were so similar:

$ apt-cache madison linux-oem-20.04c
linux-oem-20.04c | | http://gb.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
linux-oem-20.04c | | http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
linux-meta-oem-5.13 | | http://gb.archive.ubuntu.com/ubuntu focal-updates/main Sources
linux-meta-oem-5.13 | | http://security.ubuntu.com/ubuntu focal-security/main Sources
$ snap info intel-kernel
name:      intel-kernel
summary:   The canonical intel amd64 kernel
publisher: Canonical✓
store-url: https://snapcraft.io/intel-kernel
contact:   kernel-team@lists.ubuntu.com
license:   Other Open Source
description: |
type:    kernel
snap-id: eKpzfdgTkbItdivsTeTx1EnDTpfZ1Ua4
  20/stable:    5.13.0-1008.8.1 2021-12-01 (11) 333MB -
  20/candidate: 5.13.0-1008.8.1 2021-12-01 (11) 333MB -
  20/beta:      5.13.0-1008.8.1 2021-11-21 (11) 333MB -
  20/edge:      5.13.0-1008.8.1 2021-11-21 (11) 333MB -

But whatever the provenance, 5.13 is probably enough for you @snowsky :slight_smile:

Cheers, Just

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Thanks both for the great insights. :slight_smile: