GRUB Multiboot

[Stan Johnson]

Hello,

I've confirmed that the version of GRUB (2.06-2) from the 24 Mar 2022
powerpc installation CD can be used to boot other GNU/Linux operating
systems on a PowerBook Pismo (Gentoo and Void both work).

I also tried many different options in the grub.cfg file in an attempt
to get Mac OS and Mac OS X to boot, but I was not successful. I'll set
aside the disk that I've been using for testing in case anyone wants to
try to get Mac OS and Mac OS X working. I can help with testing;
unfortunately, I'm neither an OF expert nor a programmer, but I would
guess that the best way to make GRUB boot Mac OS and Mac OS X would be
for it to do whatever yaboot does.

-Stan

[Ben Westover]

Hello Stan,

Post by Stan Johnson
unfortunately, I'm neither an OF expert nor a programmer, but I would
guess that the best way to make GRUB boot Mac OS and Mac OS X would be
for it to do whatever yaboot does.

I believe all yaboot does is ask OF to boot to the partition containing
the original bootloader of OS X.
When we dual boot OS X and Linux on a PPC Mac, we just shrink the OS X
partition then put our own partitions after it, and tell OF to boot to
the new Linux boot partition instead of the old OS X one.
When you tell yaboot to boot to OS X, all it's doing is telling OF to
boot to that original OS X boot partition.
I don't know if GRUB has the ability to do that, but it would certainly
be useful.

[Mark Cave-Ayland]

Post by Stan Johnson
Hello,
I've confirmed that the version of GRUB (2.06-2) from the 24 Mar 2022
powerpc installation CD can be used to boot other GNU/Linux operating
systems on a PowerBook Pismo (Gentoo and Void both work).
I also tried many different options in the grub.cfg file in an attempt
to get Mac OS and Mac OS X to boot, but I was not successful. I'll set
aside the disk that I've been using for testing in case anyone wants to
try to get Mac OS and Mac OS X working. I can help with testing;
unfortunately, I'm neither an OF expert nor a programmer, but I would
guess that the best way to make GRUB boot Mac OS and Mac OS X would be
for it to do whatever yaboot does.
-Stan

I'm fairly sure that it would do, since as you mention above it just needs to know
which partition is the OS X volume.

Out of curiosity does grub auto-detect blessed HFS/HFS+ volumes during installation
and add them to the grub boot menu? If so, can you provide the grub.cfg. And do you
have the output of fdisk and examples of grub.cfg entries that you have tried so far?


ATB,

Mark.

[Ken Cunningham]

Fortunately, for x86_64 there is rEFIt, which like yaboot appears to no
longer be maintained (but it still works).

FYI this is the defacto successor to rEFIt, actively maintained, and is what I have been using as the bootmanager on my EFI macs the past few years:

https://www.rodsbooks.com/refind/installing.html