Can GRUB Boot Haiku?

[Jay F. Shachter]

Esteemed Colleagues:

Part of this posting is perhaps better suited to a Haiku mailing list
than to a GRUB mailing list, but there does not seem to be any Haiku
mailing list that is not utterly dead.  I joined the Haiku mailing
list specifically to ask this question, but, not only did I not
receive an answer to my question, but also, I did not even get my own
question sent back to me.

Recently I acquired a laptop with an old BIOS, although I did not
suspect just how old, until it was too late.  This laptop's BIOS is
so old ("how old is it?") that it can only access the beginning of the
internal disk.  Historically this was the main reason for the custom,
on Linux, of placing /boot in a separate slice of disk toward the
start of the disk, while the bulk of the filesystem went elsewhere
(another reason was wanting to put the root filesystem on a logical
volume, back in the days when GRUB could not boot from LVM) -- because
on such computers, not only the BIOS, but also GRUB, cannot access the
entire disk.  Thus, placing GRUB at the beginning of the disk is
insufficient; the operating system that GRUB loads into memory must
also entirely reside toward the beginning of the disk.

I did not suspect that my computer was that old, until after I had
already partitioned its disk, and already installed FreeBSD
11.0-CURRENT, and LinuxMint 17.1, and OpenSUSE 13.2, and Haiku
alphaR4, in approximately that order ("approximately" because the two
Linux systems were installed on LVM volumes, and you never know
exactly where LVM is going to put those things, but I did create the
LinuxMint volume before creating the OpenSuSE volume).  I have already
invested a huge amount of effort on some of those operating systems,
especially FreeBSD, which is never even minimally useful until you
invest a huge amount of effort in it, really sometimes I wonder why I
bother, but I digress.  The point is that I am not now going to
repartition the disk and reinstall the operating systems differently,
I have to make the best of what I have.

Haiku resides toward the end of the disk, in what, on Linux, would be
called sda8 (I reserved sda7 for SkyOS, not yet installed), and GRUB
cannot boot it (this is Grub2, of course).  GRUB does not even know
that sda7 and sda8 -- or, as GRUB would say, (hd0,7) and (hd0,8) --
even exist, it only knows about slices up to sda6; if you try to say

   chainloader (hd0,8)+1

it complains about a "nonexistent partition", or words to that
effect.

I had a similar (but even harder to diagnose) problem with OpenSuSE,
which was actually partly within and partly beyond the reach of GRUB.
I solved this problem by repurposing /dev/sda5, also known as (hd0,5),
which was originally the shared swap area for my Linux systems, and
turning it into a boot area instead; swap is now another LVM volume
within sda6.  The OpenSuSE vmlinuz program was copied to the
newly-repurposed boot area, and GRUB is able to find it there.

It occurs to me that I might be able to do the same thing with the
Haiku kernel.  Linux comes with knowledge of befs and is able to read
the Haiku filesystem.  I could conceivably copy the Haiku kernel to
the (hd0,5) bootloader region (an ext2 filesystem) and then instruct
GRUB to boot it, perhaps with legacy_kernel if multiboot does not
work, providing it the equivalent of a root= argument so that it knows
where its root filesystem is.

Is this possible?  Whenever I have booted Haiku in the past, I have
used Haiku's own bootloader, instructing GRUB to do nothing more than
chainloader.  I do not even know the name of the Haiku kernel, and I
do not know what the Haiku bootloader does, perhaps it is something
that GRUB cannot be made to do, something, perhaps, far more
complicated than loading a single program into memory and transfering
control to its entry point.

The real solution, of course -- and this is not a question only for
readers of a Haiku mailing list, it is a question for all of you -- is
to obtain a bootloader that can access the entire disk.  Is there
another bootloader able to load programs from a region of the disk
that the BIOS cannot see?  Or is there a module that GRUB could insmod
that would render it able to do so?  I do not see any reason why this
should not be the case.  When GRUB loads one of my Linux operating
systems, the operating system that GRUB loads, after GRUB brings it
into memory, is able to see the entire disk, including the parts that
the BIOS cannot see; why should not another bootloader, or indeed GRUB
itself, be able to do the same?  I do not require that GRUB know the
filesystem on which the booted OS resides; I only want to be able to
boot operating systems like Haiku and SkyOS and IcarOS that are
equipped with their own minimal bootloaders at the beginning of their
disk slice, hence I need nothing more than "chainloader +1"
capabilities.  As always, thank you in advance for any and all
replies.  If this question is not of general interest (perhaps because
it was discussed in the past and everyone except me already knows the
answer to it) please reply to my personal e-mail, shown below.



                        Jay F. Shachter
                        6424 N Whipple St
                        Chicago IL  60645-4111
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                        "Quidquid latine dictum sit, altum videtur"