[lfs-support] Configuring GRUB2--Request for a Logic Check

Ken Moffat zarniwhoop at ntlworld.com
Sat Nov 9 09:57:31 PST 2013


On Sat, Nov 09, 2013 at 10:42:14AM -0600, Dan McGhee wrote:
> I wanted to respond directly to you, Ken, because your original was so 
> detailed and obviously took a long time.  Thanks for that.
> 
> I'm keeping your suggestions for the "if all else fails" part of my 
> work.  In what I have observed, the Boot Manager is trying to "hand off" 
> to a boot loader.  I get a really, really quick screen that has two 
> very, very short lines--that's all I can distinguish--before it moves 
> almost instantaneously to the Ubuntu grub screen.  That's why I think 
> it's not a kernel problem----yet.
> 
 Understood.  I've no idea what happens on efi.  So I looked for
something detailed and useful about grub efi booting on intel _mac_.

 Ubuntu's best effort seems to be the *old* page at
https://help.ubuntu.com/community/UEFIBooting (the newer page it
links to says the old one might be better for macs).  That points to
a major source of the kernel problems (a mix of EFI 1.x and UEFI
2.x).

 Arch goes into some detail at
https://wiki.archlinux.org/index.php/GRUB#UEFI_systems_2 but I get
the impression they do things very differently from ubuntu.

 There is a page at
http://www.rodsbooks.com/efi-bootloaders/grub2.html which talks in
general terms - possibly targetted at windows users, I'm not sure if
it will tell you anything you haven't already discovered.

 The gentoo links that google found all seemed to be untested.

 A mageia link noted that EFI is very flexible so every vendor (I
think the writer means every distro) does things differently.
(Reminds me of VSAM - "a flexible and powerful tool", really easy
for the unwary to screw things up).

 All I can suggest is that you try editing ubuntu's grub.cfg [
perhaps using 40_custom rules in the longer term, but as a first
step I would just make it writable and edit it ] so that you can add
an LFS entry to the ubuntu grub menu.  That might allow you to prove
that the LFS kernel is usable, or alternatively to prove that the
required parms aren't what was expected.  For that, you would
need to copy the LFS kernel to wherever ubuntu has installed its
kernels.

 That's only a step on the way, and ignores many of the things you
want to eventually do, but it would break the problem down into
slightly smaller parts.

> Although your steps may be quite painful, they may be necessary.  Is 
> that called "regression testing?"  I've done a little of that myself 
> recently and regressed to the oral expulsive stage of my personality 
> development in which my hp-envy almost became hp-sattelite when I wanted 
> to make the hp-efi into hp-ufo.

 Technically, regression testing is when it used to work and you
want to see if it still does.  You haven't got a known-good setup
for LFS at the moment, so it's development.
> 
> And to refer to Bruce's analysis of what you wrote I wonder if things 
> are "horrid" because they become "simply complicated;" e.g. kernel 
> configuration from scratch.
> 
 It's more that they don't have *any* system available to them,
except what is statically built in, and minimal space.  That tends
to mean odd build dependencies (lilo), awkward user interfaces for
loading the new setup (lilo, yaboot is somewhat similar, and uimage
which used 'dd' when I had to use that).  And that is before the
weirdnesses of certain firmware (blessing with hfs|hfs+ on macs).

ĸen
-- 
das eine Mal als Tragödie, dieses Mal als Farce



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