And to add to Paul's comments ;-)

Paul Goyette wrote:
> 
> In addition to Colin's comments:
> 
> 1. When referencing the formmating utilities, you should probably include the
>    vendor names:
> 
> 	HDT = FWB's Hard Disk Toolkit (_not_ Tools)
> 	SilverLinig = LaCie's
> 
> 2. Partition info:
> 	a = 1st root partition if there is one on the drive
> 	b = 1st swap partition if there is one on the drive
> 	c = the whole drive, regardless of partitioning
> 	d = usually, the MacOS Driver partition - useless for MacBSD
> 	g = 1st user partition
> 
>    Additional partitions (of any type, including MacOS) are assigned to any
>    remaining, available letter in alphabetic order.  So, a second user 
>    partition would be e, not h!  Partitions other than the ones listed above
>    are assigned in the order in which the partitions are listed in the drive's
>    partition map;  note that at least some partitioning utilities will reorder
>    the map so that partitions are listed in the order they are arranged on the
>    disk.

Actually, I think that e (and maybe f) are normally reserved for
additional Root type partitions, so you'll start with g, then hit h, then
back up to f, and finally e, although I could be a little off on that.
I've got a drive with 1 Root partition (a), 1 Swap (b), whole disk (c),
MacOS driver (d), and 3 Usr type partitions (f,g,h) mounting /home, /var,
and /usr, respectively.

> You might also want to note that it is possible to have multiple root
> partitions
> on a single drive.  In this case, the first one (based on the partition
> map) is
> "a" and any others get a free letter.  If there are multiple root partitions,
> you need to specify the partition name in the Booter in order to boot from any
> but the "a" partition.

As I said above, I think that at least "e" is reserved...but I haven't
looked at the code, so I could be wrong quite easily :-)

> And, as Colin pointed out, the number portion of the drive number is
> determined
> as follows:
> 
> 1. Search each SCSI bus in order, starting as scsibus0 (note, for now we only
>    support one scsi bus, but this could change in the future).
> 
> 2. On each bus, scan the bus for each scsi target in order, starting with 0
> and
>    going up to the maximum target for the bus (6 is the limit for old scsi-1,
>    scsi-2 wide and scsi-3 go up to 14).

Just wondering, on a wide SCSI bus, what ID is the controller?  Is it
always the last one?

> 3. For each target that exists, determine its type:  hard drive is "sd", tape
>    drive is "st", scanner is "ss", network card is "se", CD-Rom is "cd", and
>    other is "su" (u for unknown).  I think there's also a separate "ch" for
>    CD-ROM changers.

I think that uknown SCSI devices are actually "uk" (or at least that's
what my config file used the last time I looked at it), although I can't
at the moment think of a SCSI device which falls outside of one of the
already specified categories...

> 4. Now that you've determined what device type to use, simply assign the next
>    available number.  So the first scsi disk drive is sd0, and the first scsi
>    tape drive is st0, regardless of what their scsi addresses are!
> 
> Also, please note that the above assignment scheme only applies to GENERIC
> kernels.  If anyone doesn't like this scheme, they are encouraged to compile
> their own kernels with the particular devices hard-wired in the configuration
> file.

Yep, I need to remember to add this to the kernel HOWTO...

Later.

-- 
Colin Wood                                 cwood@ichips.intel.com
Component Design Engineer - MD6                 Intel Corporation
-----------------------------------------------------------------
I speak only on my own behalf, not for my employer.