Re: [gentoo-user] Grub boots to command prompt

[Alan McKinnon]

On Thursday 24 December 2009 18:32:22 Daniel D Jones wrote:
> > Your next paragraph indicates that (hd0,0) is not in fact root, but (what
> >  will eventually be) /boot.
> >
> > Your root is likely to be (hd0,2)
>
> Eh?  Your grub root should be where grub is installed, shouldn't
>  it?  That's  /dev/sda1 on my system, which grub sees as hd (0,0).  When
>  the file system is mounted, that partition mounted under /boot but grub
>  still needs to know where to find the menu.lst and various stage files on
>  initial boot, and that's hd (0,0).
>

grub doesn't have a concept of "root". It's a bootloader, not a OS, and 
doesn't mount anything. It just reads data directly off disk volumes and 
(sometimes) has drivers to interpret the raw data.

When you say "root" that can only make sense in the context of an OS that uses 
a "root", so I interpreted it as such.

grub is installed wherever you installed it. You can put it on any arbitrary 
drive you feel like, or even in the first sector of any arbitrary partition if 
the drive supports such. All you have to do is tell grub where it is.

Now, that introduces a wrinkle. On a PC, the BIOS does not support stage 1 
booting off a partition. The stage 1 code MUST exist on the MBR of a DRIVE 
(blame msdos for this stupid idea) so you want to install grub to /dev/sda or 
(hd0)

I strongly suspect that you are conflating the operation of a bootloader with 
the OS. At boot time Linux conventions have no relevance whatsoever and are 
not valid, as Linux is not running yet. grub Boots Linux, it is not Linux and 
does not work like Linux. Much the same way as a starter motor starts a petrol 
engine but a starter motor is not a petrol engine and does not work like one.


-- 
alan dot mckinnon at gmail dot com