[qubes-users] modifying Qubes ISO

I need help to modify the Q4.1 installer ISO file. I did learn how to
pack & unpack isos. That is fine. The idea is a new install on a larger
SSD of Q4.1 instead of risky "upgarde" tentatives that finish less
clean. (benefit: if it fails I can go back to running Q4.0)

1) I naïvely placed a new kernel in /extrakernels but that does not seem
to impress the boot-loader. I find no way to select which kernel to boot.

2) Then I tried to boggle with grub.cfg -- no succes either.

3) I wonder if I can copy the vmlinuz and initrd file from my (working)
Q4.0 and simply overwrite the corresponding files in /isolinux?

Subquestion: initrd-5.10.90-1.fc32.qubes.img has 77M, my Q4.0 initrd
file only 23M. That sounds weird...

Each test means: open case, remove ssd, put ssd, test Q4.1 install (it
fails), reopen case, put all back, but then BIOS does no longer
recognise UEFI, so boot a life debian, go to a ethernetcable, install
efiboomgr, repair UEFI, reboot good'ol qubes -- restart.

I lost hours and start to get desparate .... please help!

haaber:

I need help to modify the Q4.1 installer ISO file. I did learn how to
pack & unpack isos. That is fine. The idea is a new install on a larger
SSD of Q4.1 instead of risky "upgarde" tentatives that finish less
clean. (benefit: if it fails I can go back to running Q4.0)

1) I naïvely placed a new kernel in /extrakernels but that does not seem
to impress the boot-loader. I find no way to select which kernel to boot.

Not entirely sure what you are trying to accomplish here. A Qubes 4.1 install ISO with a newer kernel? Can't you install 4.1 with a recent prebuilt ISO and update the kernel after? If it's due to hardware incompatibilities, I've seen some install and update on one system, then move the hard drive to the one with newer hardware.

If you're sure you need a custom ISO, I think you may need to build that yourself. The 4.0 documentation is here (Qubes ISO building | Qubes OS), but 4.1 should be similar. If you go this route, you'd have to figure out how the builder determines which kernel to use and change it before completing the build.

haaber:

I need help to modify the Q4.1 installer ISO file. I did learn how to
pack & unpack isos. That is fine. The idea is a new install on a larger
SSD of Q4.1 instead of risky "upgarde" tentatives that finish less
clean. (benefit: if it fails I can go back to running Q4.0)

1) I naïvely placed a new kernel in /extrakernels but that does not seem
to impress the boot-loader. I find no way to select which kernel to boot.

Not entirely sure what you are trying to accomplish here. A Qubes 4.1
install ISO with a newer kernel? Can't you install 4.1 with a recent
prebuilt ISO and update the kernel after? If it's due to hardware
incompatibilities, I've seen some install and update on one system, then
move the hard drive to the one with newer hardware.

Thanks for your reply! Badly enough, I rather need a "kernel downgrade":
any xen kernel 5.x will freeze my Q4.0 system between seconds and some
minutes (a curse on Intel and Dell at this point for selling shit at
high prices). So my qubes runs for one year now in a "disaster mode"
with a 4.19 kernel for xen, and normal 5.x kernels in guest VM's (mainly
debian). The same happens when I try a fresh install with Q4.1: install
attempts with the std ISO fail 100% by system freeze before finishing
installand leave an unbootable SSD behind.

So, since Q4.0 works with this workaround, I'd like to do the same with
Q4.1 in an -otherwise- fresh install. It should it possible to replace
the kernel (which, after all, are just some executable files) by a
working one, right? Of course, the problem is that few people seem to
understand how exactly the boot-process works -- that has been
outsourced to 'savant scripts' long ago. At least I tried several dozens
of webpages on the subject, and I still don't see clear. Precise
documentation would be appreciable ...

If you're sure you need a custom ISO, I think you may need to build that
yourself. The 4.0 documentation is here
(Qubes ISO building | Qubes OS), but 4.1 should be
similar. If you go this route, you'd have to figure out how the builder
determines which kernel to use and change it before completing the build.

I am afraid of that step. That would be the first time in my life that a
long build process actually finishes as planned ...

best, Bernhard

Hi Haaber,

I used to have similar freezing problems with 4.0 on my Dell laptop.
I found that it was due to an upgrade to the intel-i915 driver in X.
Replacing the new version with an older version cured it for me.

However, I've had no trouble with Qubes 4.1.

A search for "linux xorg driver for i915" gives some idea of the
problems, but it is all a bit confusing.

ah. I extracted

xorg-x11-drv-intel-2.99.917-26.20160929.fc25.x86_64.rpm (year=2016)
xorg-x11-drv-intel-2.99.917-32.20171025.fc25.x86_64.rpm (year=2017)

from old qubes ISO's. How did you install / exchange them in the running
qubes system?

alternatively, I could also place one of these inside the qubes-4.1 ISO,
where we find actually

/Packages/xorg-x11-drv-intel-2.99.917-49.20210126.fc32.x86_64.rpm

Replacing this file is certainly more easy than changing the kernel of
the ISO itself :slight_smile: Bernhard

Does using the modesetting driver instead of the intel driver help? If
not, please report this as an i915 kernel driver bug.

- --
Sincerely,
Demi Marie Obenour (she/her/hers)
Invisible Things Lab

it does not. The bug report is open & unresolved for > 1year

Thank you, Bernhard