Re: Query about command line commands

[Bret Busby]

On 10/03/2015, Andrei Borzenkov <address@hidden> wrote:
> В Tue, 10 Mar 2015 16:28:09 +0800
> Bret Busby <address@hidden> пишет:
>
>>
>> So, now, the question arises; given that the system is a UEFI/GPT
>> system, with an EFI bootloader (?) that is not accessed, that points
>> to MS Windows 8, and, using an apparently BIOS-based bootloader (the
>> once again, operational GRUB) that points to Ubuntu Linux and Debian
>> Linux, how to I get a bootloader to point to all three of those
>> operating systems, so that the same bootloader, allows me to select
>> any one of those three operating systems, to load and run?
>>
>> Does GRUB provide for that?
>>
>
> Yes. GRUB can be built for UEFI and most distributions I'm aware of
> ship multiple GRUB flavors for different platforms. How exactly
> packages are named depends on distribution, you are better ask there. I
> expect GRUB for EFI be named something like grub2-x86_64-efi or
> similar. All of them can be installed in parallel on the same system
> and be able to boot using both BIOS and EFI using the same grub.cfg.
>
> The catch22 is, that you cannot configure EFI firmware to use it unless
> you have already booted in EFI mode. And how to do it is rather system
> dependent. The first question here would be why all your Linux
> installations were done in legacy BIOS mode.
>
>

My intent was for all operating systems installations on that system,
to be done using the UEFI/GPT system.

One of the reasons for getting the particular computer, apart from its
capacity to run 32GB RAM, was to allow PC-BSD to be installed (I note
that, now, with the trouble that the last installation of PC-BSD
caused, I have abandoned the prospect of trying again in the future,
to install PC-BSD, as simply, too dangerous), in addition to at least
one installation (if not more)  of a Linux distribution, as MS Windows
takes more than one primary partition, in the FAT/BIOS/MBR systems,
and so, with one Linux distribution and an extended partition, all
primary partions are gone. The GPT system, regarding all (up to 128)
GPT partitions as primary partiitions, overcomes the problem.

The intention was to do it all, using UEFI/GPT, and I had assumed
that, in installing Debian Linux v7 on the UEFI/GPT system, that it,
and, all subsequent operating systems, in being installed on a
UEFI/GPT system, without me setting installations to be anything other
than UEFI/GPT, would automatically install as UEFI/GPT systems.

In the course of the discussion about trying to recover the pre-BSD
GRUB bootloader, I found, and had posted on the Debian User mailing
list, text from a web site to which I had been referred as a source of
a GRUB rescue disk;

"
> You could give a try to Grub Rescue : http://www.supergrubdisk.org/
>
> Good luck !
>

Hello.

Thank you for that suggestion.

At first look, that seems useful for me, for a number of reasons
(including, maybe finding the installed Win8 (nasty thing that it is),
and, eliminating the forgotten passwords, and, resetting the Debian 5
root and user passwords that I have forgotten on a different, very
important computer, so I can maybe update it).

However, ...

At
http://www.supergrubdisk.org/
is

"
I am going to modify Rescatux 0.32 roadmap so that it’s easier to
release Rescatux 0.32 even if it lacks some importants items.

 We drop UEFI Boot Support. This does not mean not being able to fix
grub systems based on UEFI. What it means is that I was going to make
sure that you could boot Rescatux cd in EFI mode without a problem.
You will be able to boot Rescatux cd from a UEFI system if the CD is
booted in legacy boot mode (BIOS) but not as EFI mode. The reason for
dropping this UEFI boot support is because of Debian Live for its
Debian Wheezy version not being good enough for enabling UEFI boot
based on grub2. I also do not want to achieve the same result by using
current SG2D and the Rescatux isolinux image as I did in the old days.
I just want a plain isolinux based ISO image and that’s it. I also do
not want to rebase Rescatux on Debian Jessie even if it’s tempting.
Once we release the stable Rescatux 0.32 we would be able to think
about rebasing Rescatux on Debian Jessie which its Live Build package
will have EFI support based on syslinux / isolinux. Not yet, but I’m
sure that they won’t release Debian Live for Jessie without EFI boot
support because it’s a must nowadays.
"

So, the question is ... does it work on a GPT/UEFI system? The above
passage, makes trying to use the application, on a GPT'UEFI system,
sound scary, kind of like flying in one of those big jet airliner
things, with the windows open, and without parachutes.
"

Now, the thing with this, is that it, in the context of what has
happened with me, in this matter, it raises the question;
Do Debian Linux 7, and, Ubuntu Linux 14.04 LTS, install and run, on
UEFI/GPT systems, as UEFI/GPT operating systems, or, are they unable
to so install and operate, instead, installing and operating as
BIOS/MBR/FAT systems, running as virtual machines (for want of a more
appropriate term), within a UEFI/GPT system, thence, apparentl;y,
disabling some of the UEFI/GPT functionality?

I do not know what is the answer to this; all that I know, is that I
had intended for each operating system installed on the particular
computer, being a UEFI/GPT computer, to be installed, using, and,
conforming to, the UEFI/GPT systems, and, not involving the legacy
BIOS systems.

Maybe, as Debian Linux, and Ubuntu Linux, have different versions,
according to the CPU upon which they are to run (eg, x386, and amd64),
they should also have different versions, to run on the different
platforms, of UEFI/GPT and BIOS/MBR/FAT?

It seems to me, to be strange, to have, on a single computer system,
an operating system installed as a UEFI/GPT system, and, two operating
systems installed as BIOS/MBR/FAT systems, and, especially, with the
three operating systems installed on the same computer, to not be able
to select any one of the three, in a single such menu, to boot; that
is, for all three installed operating systems, to be displayed
concurrently, as options, from which to select one, to boot..

-- 
Bret Busby
Armadale
West Australia
..............

"So once you do know what the question actually is,
 you'll know what the answer means."
- Deep Thought,
 Chapter 28 of Book 1 of
 "The Hitchhiker's Guide to the Galaxy:
 A Trilogy In Four Parts",
 written by Douglas Adams,
 published by Pan Books, 1992

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