Cubic

Can't boot from created ISO, installed kernels not visible in Cubic

Asked by Jim Narey

Hi, I am in the middle of a very frustrating experience with your *fantastic* tool.

Several evenings ago, within an Ubuntu 18.04 Virtualbox VM, I created a custom Live ISO based on Xubuntu 16.04.4. Amongst changes to default xdg settings I installed two custom kernels, 4.15 compiled from apt-get source and 4.17 compiled from the mainline with Ubuntu patches. It worked, it was brilliant, it saved me hours. I did a few iterations of the ISO, using the existing Cubic project files each time.

Because squashfs compression was taking a while and I was running out of space on my laptop I moved my setup to a desktop machine running Ubuntu 18.04 on bare metal. However, whatever I do or do not do in the chroot, if I install any additional kernels they do not appear in the post-chroot menu. Only the kernel which comes with the live ISO appears. This is still true if I use the previous, successful custom ISO as the source.

I created a new VM (I'd removed the old one as it had become bloated) and have exactly the same problem. I cannot see installed kernels in the post-chroot menu.

If I try to boot from one of these images (where the added kernels are not visible in Cubic) I get to the initial menu asking whether to install or try Xubuntu, then a blank screen. On an EFI machine (my actual target for all of this, with the ISO flashed to USB) it goes to a black screen after the initial GRUB menu. So it seems that the image boots with the live kernel outside of the squashfs file system then everything goes wrong when it tries to hand over to a kernel within it.

I recall, when I successfully made the first ISO, I would see many console lines saying something like 'Ignoring command as in chroot' during various apt/dpkg installations but I haven't seen these on more recent attempts.

For the VMs (to run Cubic) I have tried Ubuntu 18.04 and Xubuntu 16.04.4. The results are the same. In each case I have updated the OS with either apt-get dist-upgrade or just apt-get upgrade.

I cannot for the life of me work out what I did/did not do the first time(s) which was then different each of the other times.

Any help would be much appreciated. It was like a magic bullet the first time around!

Thanks,

Jim.

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Cubic PPA (cubic-wizard) said : 		#1

Jim Narey ,

I had to temporarily remove the ability to select alternative kernels, because others were experiencing issues, and sometimes the generated ISO would simply not boot.

There is a comment indicating this in the release notes, when you update Cubic (but most people don't read those ;-) ).

Since this capability seems important to you, I will post a note here as soon as I have re-introduced it into into the *Development* stream, so you can use it right away. I will also be sure to test with Xubuntu 16.04.

Please wait a few days, and I'll get an update out.

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Jim Narey (jimnarey) said : 		#2

Thank you so much. I'm afraid you've totally called me out on not reading the release notes.

This worked perfectly on (I think) the evening of 14 June. Is it possible for me to download the version which was the most recent at that time, as I had no other problems with it? I just had a quick look now and can find the commands (apt-get madison, apt-get policy) which provide info on candidates for a package but it's not clear these work with a ppa and having just had a look at the Cubic launchpad page I can't work out whether I need 'release' or 'trunk'?

Do you know whether this is possible and if so can you point me to the right branch?

You're right that it's important to what I'm attempting. I am trying to get Linux (right now, Xubuntu) running on a Lenovo Yoga Book (a Windows 10 2-in-1 laptop/tablet). Some fairly essential hardware (inc. SD card) sits behind some ACPI ICs which need various things enabling in the kernel to work.

Thank you so much, if nothing else for confirming this isn't me! Because I moved the system I assumed I'd changed something important and was about to devote my fourth evening to trial and error.

Thanks,

Jim.

Revision history for this message
Cubic PPA (cubic-wizard) said : 		#3

"trunk" is the development branch; the code is untested and may break
"release" is what you typically install

I'll look at the revisions this evening, and get back to you about what you could do get back up-and-running with kernel selection.

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Jim Narey (jimnarey) said : 		#4

Thank you!

Revision history for this message
Cubic PPA (cubic-wizard) said : 		#5

Jim Narey,

Would you please test the fix for this issue in the *Development* branch, and let me know if it resolves your problem? (If there are no issues, I'll promote it to the release branch so others can also benefit).

    # Remove Cubic
    $ sudo apt autoremove --purge cubic

    # Remove the *Release* repository
    $ sudo apt-add-repository --remove ppa:cubic-wizard/release

    # Add the *Development* repository
    $ sudo add-apt-repository ppa:cubic-wizard/development

    # Install the *Development* version of Cubic
    $ sudo apt update
    $ sudo apt install cubic

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Cubic PPA (cubic-wizard) said : 		#6

To check you've installed the correct version with this fix, execute...

    $ dpkg -l cubic

The version number should begin with

    "2018.06-137"

Revision history for this message
Jim Narey (jimnarey) said : 		#7

Hi - thank you so much for your help.

I tried the updated version on Ubuntu 18.04 on bare metal. Within the chroot I installed a custom kernel from .deb files and made no other changes (this included not having to fix the DNS issue, as was necessary on this machine with the latest release version).

The kernel selection menu included the added kernel but the image would not boot, as with the latest release version.

It failed at exactly the same point as the latest release version: when in either BIOS mode or EFI mode the screen goes blank after the respective menu for selecting whether to install or try Xubuntu.

As a temporary solution, I have managed to successfully make a new image with Cubic revision 28, using the following steps (in case they're useful for others):

Remove any existing version with 'sudo apt-get purge cubic'.

Go to the revision 28 source page: https://bazaar.launchpad.net/~cubic-wizard/cubic/release/revision/28

Click on 'download tarball'. Revision 28, the last before kernel selection for the ISO was temporarily disabled, can also be cloned using 'bzr branch lp:cubic/release' then 'bzr revert -r revid:<email address hidden>' from within the 'release' directory.

Do 'sudo apt-get install dpkg-dev build-essential devscripts'

Within the 'release' dir run 'debuild -uc -us'. It will fail, listing unmet dependencies (unless they all happen to be installed on your system). Install all the dependencies with apt-get and run 'debuild -uc -us' again.

A .deb package for revision 28 will be in the parent directory and can be installed with dpkg -i.

Revision history for this message
Cubic PPA (cubic-wizard) said : 		#8

Jim,

Cubic release version 2018.07-33 (from ppa:cubic-wizard/release) has the kernel selection capability.

It worked in various tests I ran. (I did not test EFI).

Can you help with this problem?

Provide an answer of your own, or ask Jim Narey for more information if necessary.

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