(In reply to Adam Williamson from comment #0)
> As things currently stand in Rawhide, the way
> https://fedoraproject.org/wiki/Changes/BootLoaderSpecByDefault has been
> implemented assumes existing systems are converted to BLS on upgrade. There
> is a grubby %post to do this:
> 
> %post
> if [ "$1" = 2 ]; then
>     arch=$(uname -m)
>     if [[ $arch == "s390x" ]]; then
>         command=zipl-switch-to-blscfg
>     else
>         command=grub2-switch-to-blscfg
>     fi
> 
>     $command --backup-suffix=.rpmsave &>/dev/null || :
> fi
> 
> and after upgrade, the old, non-BLS compatible bits of grubby will not be
> present on the system, as they are in grubby-deprecated and that package
> will not be installed on upgrade.
>

Note that this will only be the case for architectures that either have grub2-tools (for grub2-switch-to-blscfg) or s390utils (for zipl-switch-to-blscfg) installed.

On armhfp no conversion will happen and the %post scriptlet will be a no-op.

> However, this will break 32-bit ARM systems on upgrade, AIUI. These use
> extlinux, which has not been made BLS-compatible. There is a proposed Change
> to switch to UEFI for new 32-bit ARM installs:
> 
> https://fedoraproject.org/wiki/Changes/uEFIforARMv7
> 
> however, that does not propose to 'convert' existing installs:
> 
> "Upgrades from prior versions of Fedora will continue to work as they do
> currently. Devices booting with extlinux will continue to upgrade and work
> as planned."
> 
> So on upgrade to F30, 32-bit ARM systems will still be set up with extlinux,
> which will not be BLS-compatible...but grubby-deprecated will not be
> installed. So kernel updates will not work.
> 
> One way to handle this, I guess, would be to have grubby-deprecated Obsolete
> grubby < 8.40-18 "%ifarch %{arm}" in the spec. That should ensure it gets

Another option is to make syslinux-extlinux depend on grubby-deprecated, which seems to be the correct think to do since it relies on new-kernel-pkg and the old grubby to update the boot entries in the extlinux.conf file.

I see there isn't a dependency on grubby now, but I think that's a bug since without grubby the boot entries won't be updated.

> installed on upgrade. If we do later make extlinux BLS-compatible, or in
> some other way render existing 32-bit ARM installs BLS-compatible on
> upgrade, we can have a later version of grubby Obsolete grubby-deprecated,
> or something.
>

By making syslinux-extlinux to depend on grubby-deprecated, if we later switch existing armhfp installations to grub2 or something then the syslinux-extlinux cold be removed by making grub2-efi to Obsolete syslinux-extlinux. This will also make grubby-deprecated to be uninstalled due the unused dependencies.
 
> Proposing as a Beta blocker per the upgrade criteria and the update criteria
> - an upgraded 32-bit ARM system will not handle subsequent kernel updates
> correctly.

Agreed.

Created a pull-request to extlinux-bootloader package to add the dependency:

https://src.fedoraproject.org/rpms/extlinux-bootloader/pull-request/2

Aha, yes, that makes perfect sense. Good idea.

1.2-7.fc30 is built now, so let's go ahead and close this, it ought to be fixed.