RPi5 should use kernel_2712.img (not kernel8.img)

[user706]

The following (kernel8.img) works for RPi5, but is not optimal:

https://github.com/mendersoftware/mender-convert/blob/5.1.0/configs/raspberrypi/uboot/include/raspberrypi_64_config#L4-L5

Ref: https://www.raspberrypi.com/documentation/computers/config_txt.html#kernel
"The Raspberry Pi 5, 500, 500+, and Compute Module 5 firmware defaults to loading kernel_2712.img because this image contains optimisations specific to those models (e.g. 16K page-size). If this file is not present, then the common 64-bit kernel (kernel8.img) will be loaded instead."

It's better if RPi5 uses kernel_2712.img, since it has optimizations.

[user706]

By the way... (and not handled in this PullRequest)

it's not good that mender copies the bootloader into
/boot/firmware/kernel8.img
or into
/boot/firmware/kernel_2712.img (which would happend with RPi 5, in this PullRequest)

If you do

sudo apt update
sudo apt upgrade

you can destroy the setup if a new kernel is upgraded and written to
/boot/firmware/kernel8.img (or /boot/firmware/kernel_2712.img)
since it overwrites the bootloader.

See here for details: https://hub.mender.io/t/raspberry-pi-64-bit-can-destroy-itself-through-apt-upgrade/8181

[elkoniu]

Hi @user706 - thanks for this PR. I started testing it last week together with the recently released RPi images. When the testing will be completed I will add comments to this PR.

[user706]

great thanks.

[elkoniu]

@user706 I have cloned this PR into #844 to speed up testing on my side and easier rebase on top of the latest changes. When I will finish the testing and confirm everything looks fine I will ask you to rebase this PR and will merge it.

[elkoniu]

@user706 my tests confirms that everything looks to work fine.
Can you please:

1. Rebase on top of latest master branch
2. Format the commit following existing commit style:

chore: XYZ

Description

Signature

3. Sign the commit
   Above will satisfy our formal requirements for this PR to be merged.

[elkoniu]

@TheYoctoJester I have performed some basic conversion testing here: #844
Generally it looks good so if you are not aware of any possible issues which may be caused by this "better" kernel I think we can merge it.

[elkoniu]

Based on my testing with mender-convert - it looks good.

[user706]

OK.
commit is now on master.

Commit looks like this

Author: user706
Date:   Wed May 27 21:37:31 2026 +0200

    chore: use kernel_2712.img for raspberry pi 5
    
    RPi5 should use kernel_2712.img (not kernel8.img),
    which is the kernel that original
    official raspberry pi images also load when running on RPi5.

And it is signed with GPG Key ID: 938FD2002C592940
as you can see if you go here...
https://github.com/mendersoftware/mender-convert/pull/817/commits
... and then click the green Verified button.

(By the way... kernel_2712.img is the kernel which a Raspberry Pi 5 loads, when you run an original official rasperry pi image on an RPi5. So it is "the right thing to do".)

[user706]

now fixed commit, this time with --signoff

[user706]

this time the pipeline failure is not because of commit-formatting:
https://gitlab.com/Northern.tech/Mender/mender-convert/-/pipelines/2558723606