On Wed, Jun 30, 2010 at 2:10 PM, Andrew Benton <[email protected]> wrote:
> On 30/06/10 19:33, Stuart Stegall wrote:
>>
>> Seems like it should be the simplest way possible.  Personally I don't
>> like the grub-mkconfig - has failed to work for me a few times, and I
>> believe it does that due to my host system.
>>
> grub-mkconfig has never worked for me as I use btrfs for my root partition
>
>> Seems like a much more simple approach of:
>>
>> # cat<<EOF>  /boot/grub/grub.cfg
>> set timeout=10
>> set default=0
>> menuentry "LFS x.x" {
>>      set root=(hd0,1)
>>      linux /vmlinuz root=/dev/sda2
>> }
>> EOF
>>
>> Would be better.
>>
> I agree. I've always written grub.cfg by hand from examples found with
> google.
>
> Andy
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Boot Process:
Grub2 runs.

set root=, or search to set the root partition for grub.  AFAIK, this
is only useful for saying where / goes.  (ex:/ I used
(hd1,1)/boot/lfskernel, and it still worked, without setting root to
anything).

Loads the kernel by using /boot/lfskernel (if root is set), or (hd1,1)
completely ignoring whatever root is set to.

Linux loads, and the grub root is lost.  AFAIK, linux has no way of
obtaining this information.

Linux looks for the root filesystem.  These are the options I know
  root=/dev/sda1 - Loads this partition
  root not set - Load the partition set within the kernel image (Set
w/ rdev if I recall)
linux then runs /sbin/init [or whatever init= on the commandline]

(an alternative way, is if linux loads a initrd/initramfs.  Then you
can use a few shell scripts to find the root instead.  This is how
distributions make root=UUID=abcdefg or root=LABEL=os work).



So, regardless if you search or not, or set root manually, this has no
effect once the kernel boots.  You either need root=/dev/sda1, or you
need to use rdev (used to be in util-linux) to set the root.  I
believe when you compile the kernel, rdev is set automatically to
whatever / is.



-- 
Nathan Coulson (conathan)
------
Location: Brittish Columbia, Canada
Timezone: PST (-8)
Webpage: http://www.nathancoulson.com
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