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

Dan McGhee beesnees at grm.net
Sat Nov 9 12:13:02 PST 2013


On 11/09/2013 11:57 AM, Ken Moffat wrote:
> 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_.
It has been painful, but I can discuss it now and can generate options 
on how to go.
>
>   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 links in what is on rodsbooks, got me to the ubuntu one.  I'm using 
both references to do my work.  But, and this is where I owe you a real 
debt of gratitude, I took a closer look at the archlinux article.  For 
some reason, I went blowing past it when I found it originally.  Maybe 
at that time I didn't even know enough to recognize what I was reading.  
After looking at it just now, I think it's exactly what I need.  For one 
thing it resolved my paranoia about where grub would write.  I couldn't 
quite "nuke out" what 'grub-install' actually did by reading the 
script.  That page addresses that.  Therefore, if I'm missing anything 
in my manual work, I won't miss it now because I'm gonna use grub-install.

That paranoia led me to my desire to know more about the "guts" of 
grub.  But I also understand, "If it ain't broke, don't fix it."  If 
grub-install works and I don't understand why, I don't care.

The rest of it is just configuring and getting grub to look in the 
"right" places.
>
>   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).
Yes, the different distro sites seem to be rather silent on this stuff.  
And you found something that I was hesitant to mention. This stuff does 
depend a lot on vendors.  Many have written their own Boot Managers and 
I've found many comments and articles on how "buggy and unreliable" many 
are.  As of a year ago, HP was one of those that had lots of 
complaints.  That may be something else I need to research.  rEFInd and 
gummiboot, look out I may be headed your way.

I don't mind not doing things the way ubuntu does.  Since I started 
using it as a host system five or six years ago, it has more rapidly 
approached behavior that is quite similar to that other OS that has 
almost a stranglehold on the market.  In fact, Ubuntu "caved in" and is 
paying "the fine" to use secure boot.

As I've said, I'd like to accomplish two things: 1) get LFS-7.4 to boot 
in a UEFI environment, and 2) do it in a way that will be useful to LFS.

Thank you very much, Ken, for your efforts.

Dan




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