Subject: Re: Booter documentation
To: None <nigel@ind.tansu.com.au>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 11/03/1997 12:36:54
> >								There is a
> > place where you fill in the name of the partition to boot from. As i have
> > some experience with unix I assumed this to mean something like
> > /dev/sd0a.
> 
> 	I think it does. (I am away from the code at the moment)
> 
> > The fact that it actually implies something like
> > "NetBSD Root & Usr" is not very intuitive...
> 
> 	This style of name isn't really used by anything except low-level
> utilities which deal directly with disk partitions. If you enter _that_
> name into the Booter, it won't know what you are talking about.

Actually, it is supposed to be the name you gave the partition in the
partitioning program. If you only have one root partition, it doesn't matter.
But this way permits us to have an "altroot" partition. By changing the
name given in the booter between one of two valid names, you can
switch between a known-good and an experimental root file system.

> __________________________________
> 
> 	The partition numbering under NetBSD can be confusing for first-
> time users. (or Linux users!) sd0a actually implies _something_ like
> "the first SCSI ID which contains a root partition". Not very intuitive.
> The Booter could be improved so that this mapping was explained a little
> better. e.g.:

sd0 is the first scsi hard disk found, regardles of the presence or abesnce
of a root partition. On my IIsi, sd0 is the 40 MB hard disk which came with
the computer (and is now essentially a system folder).

> 1) List both the 'Mac OS' and 'BSD style' partition names in the Booter

The problem with trying to mention the 'BSD' partition name (sdXa) is
that if you have a custom kernel, you're supposed to wire down the
hard disks. If you then add a hard disk w/ an ID  which is not greater than
the previous max ID #, that kernel's idea of sd# and the booters (which
would have to have a GENERIC-style numbering sequence). Admittedly this is
an obscure situation, but I think it's just better to not mess with the
'BSD' partition name.

> 2) Have a pop-up window (like MkFs or the Installer) in the Booter, which
>    lets you select the SCSI ID and Partition Name you want to boot from.
>    The Booter could then display this information instead of the current
>    cryptic string.

I think adding such a pop-up would be a good thing. Typing in the # is fine,
but being shown all the choices for partitions would make life easier. :-)

Especially as it should show partitions which can't be "root" partitions
in gray, warning the user if there's a problem (like the "I'm a Root
partition" bit isn't set).

> 3) Include [a reference to a document which has] information about common
>    NetBSD to Mac OS partition names in the BooterManual.
> 
> I am not sure that the Booter is the correct place to put this sort of
> detail, however. What do other people think?

?? The namespaces are independant; there's no definitive mapping.

> __________________________________
> 
> 	The BooterManual currently says:
> 
> Partition Name and Root SCSI ID 
>     The Booter needs to know which partition contains your kernel, if you
>     are booting from the BSD/Mac68k file system. If you do not enter a
>     partition name here, the Booter will make a few feeble guesses based
>     on the SCSI ID you specify for your root file system. For best results,
>     then, you should enter the name of the root partition (assigned when
>     you formatted the drive) in the Partition Name box, and the SCSI ID of
>     the drive containing that partition in the Root SCSI ID box 
> 
> 
> 	This could certainly be improved, at the very least it could give
> an example of a valid 'Partition Name'.

That'd be good. Or maybe also say the name is what's shown in the Name
column in Mkfs (and change the appropriate column in Mkfs to be clear). :-)

I think if we tell folks we're talking about the name you see "there" (
where ever "there" ends up being), we're fine.

Take care,

Bill