[Bug 1922342] Re: HIrsute live session takes ages to boot on BIOS systems

[Thomas Schmitt]

Hi,

> I noted Thomas (scdbackup) asked for firmware details

The motivation is to find enough affected hardware so that the delay
can be reproduced by developers. Obviously it did not happen with the
regular testing machines.

So my request/proposal was for the general public:
Tell which machines are slow at booting the current Ubuntu ISOs.

---------------------------------------------------------------------------

If it becomes reproducible for a developer who understands the boot
sequence well enough to identify the actual step which needs too long,
then a chance for a fix or a workaround could emerge.

My suspicion is that some part of GRUB gets different info from the
firmware, depending on whether the second MBR partition exists or not.
The info in the case of an existing second partition then would cause
this or another part of GRUB to wait for something that won't happen
in reasonable time.
I confess that this is a wide and vague theory. But the insight we have
does not yield more than that.

So we need to bring together a machine with that problem and a developer
with sufficient interest and GRUB knowledge to find out what's happening
and to start discussing the problem with grub-devel mailing list.
I assume that the GRUB developers will not be interested yet, because the
problem is a reaction of a mild violation of GPT specs by Ubuntu's ISO
with its second MBR partition of type 0x00 and boot flag.

---------------------------------------------------------------------------

Another path for a sustainable solution would be if we find enough
affected machines to convince Ubuntu to offer two flavors of ISOs.
One "for picky EFI" with GPT and a fully specs compliant Protective MBR.
(Won't work for old HP laptops.)
One "for picky BIOS" without GPT but rather an MBR partition table.
(Won't work on newer Lenovos.)

We had both versions already when the new Ubuntu ISO layout was developed.
Both could still serve the majority of BIOS and EFI systems. Their success
would differ only on the mentioned machines which show a peculiar
interpretation of EFI specs and BIOS tradition.
"For picky BIOS" was the ISO layout at the beginning of
  https://bugs.launchpad.net/ubuntu-cdimage/+bug/1886148
and "for picky EFI" was the layout at its end.
The attempt to have a single ISO for all yielded the current layout, which
was the result of
  https://bugs.launchpad.net/ubuntu-cdimage/+bug/1899308

Have a nice day :)

Thomas

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https://bugs.launchpad.net/bugs/1922342

Title:
  HIrsute live session takes ages to boot on BIOS systems

Status in casper package in Ubuntu:
  Confirmed
Status in casper source package in Impish:
  Confirmed

Bug description:
  First of all, I change the description of this bug because, thanks to
  Chris Guiver comments, I could check that the live session effectively
  works but it takes too long to complete. That's why I change the
  description of the bug from live session does not boot to live session
  takes ages to boot. I hope this is the best approach to this.

  I think the problem is the same as described here:
  https://discourse.ubuntubudgie.org/t/20-10-grub-error-can-t-find-
  command-grub-platform/4292. I can see prior to grub menu, briefly, the
  same error: Error can't find grub_platform. After the solution
  described below, this error is not showed and the system is able to
  boot.

  I try making the live usb using startup disk creator and with gnome-
  disks --> Restore disk image and get the same results.

  The live-usb has a gpt partition table instead of mbr like 20.04 live-
  usb has. That implies, I think, that the first one does not boot on
  BIOS systems and the second does.

  I try the same live-usb on an EFI laptop and it boots perfectly
  (perhaps it takes long time, but more less than in this case.

  If I try the solution described here:
  https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1905491/comments/8
  then it works.

  ProblemType: Bug
  DistroRelease: Ubuntu 21.04
  Package: casper 1.461
  ProcVersionSignature: Ubuntu 5.11.0-13.14-generic 5.11.7
  Uname: Linux 5.11.0-13-generic x86_64
  NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
  ApportVersion: 2.20.11-0ubuntu61
  Architecture: amd64
  CasperMD5CheckResult: pass
  CasperVersion: 1.461
  CurrentDesktop: ubuntu:GNOME
  Date: Fri Apr  2 09:55:24 2021
  LiveMediaBuild: Ubuntu 21.04 "Hirsute Hippo" - Beta amd64 (20210331.1)
  ProcEnviron:
   TERM=xterm-256color
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=gl_ES.UTF-8
   SHELL=/bin/bash
  SourcePackage: casper
  UpgradeStatus: No upgrade log present (probably fresh install)

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