Grub installation. First potential Fedora killer

[Adam Williamson]

On Mon, 2014-01-06 at 00:43 -0700, Chris Murphy wrote:
> On Jan 6, 2014, at 12:04 AM, Adam Williamson <awilliam at redhat.com> wrote:
> 
> > On Sun, 2014-01-05 at 22:52 -0800, Adam Williamson wrote:
> >> On Thu, 2014-01-02 at 23:32 +0100, Jean François Martinez wrote:
> >>> I have a nice booter setup and a nice _main_ Linux installation.  Last
> >>> thing I would want is a distribution I am _testing_, that is Fedora 20
> >>> forces on me it will be my main installation and forces me to choose
> >>> between installing Grub on the MBR or not at all.
> >> 
> >> Why? "Not at all" is precisely the correct action for a grub2-based
> >> distribution in this case.
> >> 
> >> I think we should do grub2-mkconfig for such installs, though it's a bit
> >> tricky to refactor anaconda's bootloader install code to do so. I might
> >> have a shot at it if I get a spare minute, though.
> > 
> > Well, hum, it doesn't look hard at all, in fact, at least a simple
> > version. See attached patch (untested, but what could possibly go
> > wrong?!). I'm not subscribed to anaconda-patches-list ATM, but CCing
> > anaconda-devel-list to see what the anaconda devs think. I think it's
> > reasonable to install a config file and device.map when 'skipping'
> > grub2-bios bootloader install, especially given our standing advice to
> > people who want to do chainload-style multi boot is "skip bootloader
> > installation then setup configfile booting after install".
> 
> There's an RFE bug floating around for this. I asked a while ago on grub-devel@ whether grub-mkconfig depended on grub-install being done first, and I got a kinda yesish answer that wasn't all that convincing. But the suggestion was to use 'grub2-install --grub-setup=/bin/true /dev/sdX' before grub2-mkconfig. This causes all the parts of grub to be installed except the singular thing people object to, and is the sole reason why they say they don't want a bootloader installed - which is boot.img being written into the MBR.
> 
> I've tested that combination and it's safe. So if the code were changed just that "no bootloader" simply means *adding* --grub-setup=/bin/true and doing everything else we already do, that'd be the easiest fix that helps the most people IMO.
> 
> BTW I think device.map is deprecated (?).

I dunno, it's in there for the regular grub2 install so I kept it for
the 'non-install-install' I'm suggesting.

bootloader.py is really falling-off-a-log-simple code, it wouldn't be at
all difficult to implement just about any approach to this, AFAICS.
-- 
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Twitter: AdamW_Fedora | XMPP: adamw AT happyassassin . net
http://www.happyassassin.net