Re: installing NETINST 20190127 on Mac mini G4
On 1/28/19 6:53 AM, John Paul Adrian Glaubitz wrote:
> On 1/28/19 2:30 PM, Rick Thomas wrote:
>>> Yaboot is unmaintained upstream and does not support modern ext4 features. In
>>> order for Yaboot to work properly, you have to turn certain features in ext4
>>> off, otherwise it won't work and the boot fails.
>>>
>>> Unless someone picks up maintenance work on Yaboot and makes it work with
>>> modern ext4 versions, I don’t see any particular reason to keep Yaboot.
>> It’s not necessary to make yaboot work with modern ext4. It’s only necessary
>> to have a separate /boot partition which is ext2, as is the current procedure
>> when the user chooses LVM partitioning. Yaboot already requires a separate hfs
>> bootstrap partition, so I don’t think having a separate ext2 /boot is that
>> much of a stretch.
> But again, what is the exact gain in keeping Yaboot? Does Yaboot have any
> features which you are missing in GRUB?
If Yaboot works but GRUB doesn't, that's the gain in using
Yaboot at this point. I haven't tested GRUB on a G5; maybe
it works there. I've confirmed that GRUB, at least the one
on the Debian 10/sid CD, doesn't work on a PowerBook G3
Lombard (or at least its installation fails). I think the
AppleBoot partition needs to be HFS (would HFS+ also work?).
And I think Open Firmware can only access HFS, HFS+, UFS and
ext2 partitions. So the suggestion above to use an ext2-
formatted /boot would likely work if Yaboot can't boot a
kernel from an ext4 partition. If GRUB can be made to work
and can live in the 1 MB AppleBoot hidden HFS partition,
then that would be fine. I think people only like Yaboot
because it works, even if it's buggy. Though I understand
the problems with it not being supported upstream.
> ...
>
>> If the only known bug is that it doesn’t support modern ext4 features,
>> I have to say that’s something we know how to live with — a separate ext2
>> /boot partition fixes the problem.
> But what's your problem with GRUB? I really don't see the point, sorry.
>
> ...
> Which PPC hardware supports Yaboot but does not support GRUB? I'm
> not aware of any.
Well, at least the PowerBook G3 Lombard, so far. I haven't
tested on the Pismo, PowerBook G4, or G5. Is the GRUB on the
Debian 10/sid CD a good candidate for testing?
>
>>> partman-ext3 still contains a work-around on powerpc [1] which I would
>>> like to get rid of. The workaround turns off 64-bit support in ext4
>>> and checksumming of metadata, both features are desirable to have
>>> these days.
>> If the reason for that work-around is solely to allow yaboot to work
>> with an ext[34] root, I think my proposal solves the problem. As long as
>> yaboot only has to deal with ext2, you can remove the work-around any
>> time it’s convenient.
> I don't want to work on Yaboot, sorry.
>
> Adrian
>
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