grub2 and setting crashkernel kernel argument

[Kevin Kofler]

Jason L Tibbitts III wrote:
> You can also edit grub.cfg directly, but it gets wiped out if anything
> ever runs grub2-mkconfig.  Finally, grubby has options for modifying
> kernel arguments, but I do not believe that goes in and does anything
> with the /etc/default/grub line so again that gets wiped out of anything
> runs grub2-mkconfig.

But does anything in Fedora actually run grub2-mkconfig automatically? 
Kernel updates sure don't, they have grubby edit the grub.cfg file directly 
instead.

I wonder whether it might actually make sense to patch grub2-mkconfig to no 
longer emit that warning and to make it a packaging guideline that RPM 
scriptlets MUST NOT run grub2-mkconfig. The template system may be a nice 
idea, but it doesn't cover everything, it makes things more complicated, and 
it doesn't seem to be actually needed in Fedora, thanks to grubby.

On the other hand, unfortunately, tools such as kcm-grub2, which we probably 
want to package for Fedora at some point, run grub2-mkconfig, and we can't 
even blame them for that given that it is what GRUB upstream recommends. :-( 
(That said, kcm-grub2's KAuth helper's code also scares me for other 
reasons:
* The config file to write to is soft-coded as a configuration option, which 
means that giving out org.kde.kcontrol.kcmgrub2.save permissions to a user 
essentially gives that user root. (It doesn't just allow to "Save the GRUB2 
Bootloader settings" as the action description claims, but to write to ANY 
file on the system as root.)
* The executable names to run are hard-coded as grub-*, which is wrong for 
Fedora.
IMHO, the proper solution would be to make both of those compile-time CMake 
options.)

So the situation is indeed a mess.

        Kevin Kofler