boot error, cannot upgrade kernel

[Gary Aitken]

On 1/7/22 12:55 AM, Ralf Mardorf via ubuntu-users wrote:
> On Thu, 6 Jan 2022 22:13:40 -0700, Gary Aitken wrote:

> I can't tell you what's going on, but I can comment on /etc/default/rcS.
> This file is aimed to contain defaults for initscripts, but Ubuntu and
> almost all other Linux distros, migrated to systemd, hence initscripts
> are replaced by systemd units. Ubuntu and almost all other Linux distros
> don't follow the UNIX alike approach to do one things well and to use
> human readable scripts for startup, it's using a binary blob that does
> startup not well and tons of other things, completely unrelated to the
> boot process. However, another bloatware asking for trouble is GRUB,
> even while it has got some pros. You are likely encountering one of the
> GRUB issues, that never get a fix. I stay away from GRUB, migrated to
> syslinux a long, long time ago. To fix your issue consider to stay away
> from GRUB repair features, try repairing your non-booting install using
> a live media, e.g. an Ubuntu USB stick. GRUB is a bootloader, it's not
> aimed to repair broken installs.

I've tried repairing it with a Ubuntu 21.10 USB stick; but I can't find a
way to repair the boot from that.  I see only two options:
   "Try Ubuntu"
   "Install Ubuntu"
Under install, I got to the "Updates and other Software" page, where I see
   "Other Options",
but repairing boot is not one of them.
There is an option to configure a secure boot, but that's not what I want;
I want to repair the boot blocks.
So I choose "Minimal Installation" and continue, and get to
"Installation Type", where my choices are
   "Reinstall Ubuntu 21.10"
   "Erase Ubuntu 21.10 and reinstall"
   "Install Ubuntu 21.10 alongside Ubuntu 21.10"
   "Erase disk and install Ubuntu"
   "Something Else"
If I choose "Something else", I get a page that doesn't display properly
but appears to be showing the existing disk partitions and a way to
repartition, and possibly fix the boot blocks but it's not obvious because
I can't read the top part of it.

If I start using the "Safe Graphics" option from the USB stick, I go through
the same steps except the dialogs occupy about a quarter of the display and
are barely readable, but the partitioning page still has some text hidden
behind what appears to be a disk allocation bar graphic.

There's a /dev/nvme0n1 which appears to be the SSD, with the following
partitions and check boxes which I can't check:
   free space                1 MB
   /dev/nvme0n1p1 efi      536 MB
   /dev/nvme0n1p2 ext4  499568 MB   Ubuntu 21.10
   free space                1 MB
  and a /dev/sda
   /dev/sda1              3111 MB   unknown
   /dev/sda2                 4 MB   unknown
   /dev/sda3                 0 MB   unknown
   free space                2 MB
At the bottom it says:

Device for boot loader installation:
   /dev/nvme0n1
with additional choices for
   /dev/nvme0n1p1
   /dev/nvme0n1p2  Ubuntu 21.10
   /dev/sda        usb stick
   /dev/sda4

I looks like it has the proper device selected for reinstalling the boot
loader, but I can't select anything from the check boxes in the partitioning
scheme; the "New Partition Table..." button is greyed out, and I don't want
that anyway; and the only other button is "Revert", which I also don't want.

Under the boot loader part, the "Install Now" button is greyed out, and the
only other options are "Quit" and "Back"

Gary