Bug#1033737: flash-kernel: Unable to run flash-kernel on EFI-based systems

[Isaac True <isaac@is.having.coffee>]

> Why would you have to run flash-kernel again?

When it's being initially installed it won't have the additional command line flag that forces it to ignore the EFI check, so it won't run and you would have to run it manually afterwards with the flag. I agree that an env variable/config file would be better here.

> The name FK_FORCE_EFI=yes seems a bit backwards; it is ignoring 
the presence of EFI, not forcing it to behave like EFI. FK_FORCE_NO_EFI? FK_IGNORE_EFI? Names are hard.

My intention behind the name was something like "force *despite* EFI", but I think FK_IGNORE_EFI does indeed fit a lot better.  

> I overall like this approach, although the main drawback is having to write to /etc/default/flash-kernel 

I agree with this - it's a bit more awkward having to create and write a file, but I like that it opens the door to allow both methods to work. The user can either set the env variable, or it can be set in the file itself. I'm not sure if it makes sense to add the "! ischroot" check like in that merge request though, as I feel like that's a different topic. What do you think?

Cheers,
Isaac