On Fri, 24 Jul 1998, Mike Schabert <mikeride@prez.buf.servtech.com> wrote:
>> the Linux booter would not attempt to grab the first Unix-root partition
>> it sees, because (I should have remembered this) it specifically requires
>> the root device and partition as one of its boot parameters.
> 
> But does it take a partition name or a partition number as the partition
> param? If the name...then it'd likely be unique to a particular partition
> (or at least could be made to be)...if it's the partition letter...then it
> would depend on whether MacLinux is using "dynamic" partitioning like we do
> (i.e. sd0a is by definition just the first un*x partition it sees & not
> necessarily the first partition on the disk) or if they actually have set
> partition letters whether or not the partition is mac, un*x, or whatnot.

It's by letter (well, number, actually) not name.  At least for the Mac,
lettering looks to be based exclusively on position from the beginning of
the drive, e.g. for the first SCSI device...

/dev/sda1 (partition map)
/dev/sda2 (driver)
/dev/sda3 (first partition)
/dev/sda4 (second parition)
...and so on...

Coming from a Linux background, when I started looking at how MacBSD did
partition numbering/lettering, I thought to myself "these guys are nuts!" =)

However, I just tried to get our hardware guy to give me a nice, clean
explanation, and he went off onto a tangent about primary versus logical
drives, and only being able to have four primary drives, and two paritions
being taken up to describe the logical partitions.  As far as I can tell,
the latter parts are hardware-specific (he works on Intel boxes only),
because I haven't run across the logical/primary question _anywhere_ in
either the MacLinux or MacBSD materials or discussions. (consensus was
that it's probably due to the controller - does anybody out there know?)

And then there's Linux on the PowerPC, which I have yet to figure out in
how the numbering/lettering works for specifying the root partition in the
boot parameters.  So at this point I just think _everybody_ is nuts. =) =)

On Fri, 24 Jul 1998, Bob Nestor <rnestor@metronet.com> wrote:
>> As soon as the Installer gets the device, it jumps right in and tries to
>> mount everything it can (I assume), and then bombs with a mountfs()
>> error, which half the time hangs my entire system.  In for a penny, in
>> for a pound: Why doesn't the Installer just use the same partition
>> dialogue as Mkfs, seeing as they already use the same device dialogue?
>
> I believe the Installer uses or tries to use the same lookup scheme as 
> the kernel does. It looks for partition types and validates them looking 
> at the flags.  Since the Kernel does really have a dialogue with the user 
> about selecting partitions for use during boot, making the Installer do 
> this could cause a lot of user problems.  The user might be able to do an 
> Install but not be able to boot up the finished result.
 
Okay, hold on.  The Booter takes a drive and partition (by name, letter,
whatever) as an explicit parameter.  Maybe it's default lookup scheme is
the same as the Installer, but _not_ if the Booter is passed an explicit
option.  Is this not how it works???  Because the Installer lacks a similar
such option, it's choking on Unix root partitions that may or may not be 
BSD paritions, because it only has this default scheme, which is currently
flawed and assumes (erroneously) any Unix root partition must be a BSD root
partitions _and_ then assumes (erroneously again) that it must have an ffs,

All I'm suggesting is a dialogue before the Installer starts making this
chain of incorrect assumptions.  If the default lookup scheme is the default
in this dialogue, fine.  But at least then I've the option of pointing the
Installer in the right direction before it goes and blunders spectacularly
due to reasons that we are aware of, but have no way to deal with because
the assortment of partition formatting tools being used out there are
apparently so varied in how they work.

If someone overrides the default in the Installer, then does the same but
differently in the Booter, and can't boot as a result, well... tough.
They should RTFM and remember their options between the two applications.
(Sorry, not meaning to get all vehement.  Really.  Just frustrated.  =/ )

>> And one last question: Think there's any chance of using something akin
>> to LILO, the Rhapsody dual-booter, or OpenFirmware for selecting an OS

Oops, I walked into that one. =)  I meant "akin" only in the end result
of being able to select an OS at start-up, but not with respect to the
particular hardware or means by which this would be done.
-jope

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