Subject: Re: Unattended booting
To: Donald Lee <email@example.com>
From: Bill Studenmund <firstname.lastname@example.org>
Date: 09/29/2002 18:48:03
On Sun, 29 Sep 2002, Donald Lee wrote:
> At 3:36 PM -0700 9/16/02, Bill Studenmund wrote:
> >On Sun, 15 Sep 2002, Donald Lee wrote:
> >There is only one tool you should not use when using Apple partitions, and
> >that is installboot. It will trash an apple partition map. Other than
> >that, all works well. All of the disks I use use Apple partition maps.
> >sysinst hasn't got it instrumented, but an update should work (I think).
> OK. I just want to be clear, this is what I understand.
> OF needs an HFS partition to load ofwboot.
There is ofwboot, and ofwboot.xcf. They are two different representations
of the same program.
ofwboot is a memory-image version. It is loaded by bootxx, which the
firmware loads it at an address and jumps to a specific location. bootxx
gets shoved into a "driver" partition in an Apple partition map. bootxx
then knows what blocks to read off of the disk, and loads them to build
ofwboot. OF 1.0.5 and 2.0 machines will use this driver to boot. I think
OF 2.4 machines will too, with the cache bug fixes. We haven't gotten OF 3
machines to use this trick.
ofwboot.xcf is an XCOFF format version of the program. When loading files
off of file systems or netbooting, OF can deal with XCOFF files. OF 3 can
deal with ELF files too, but we just go with the XCOFF version for
simplicity. All versions of OF can load files off of FAT-16 file systems,
and OF 3 can read hfs. For OF 3 systems, since we can't get them to read
the "driver" partition, we add an hfs file system and put ofwboot on
The hfs partition is only needed if you're using ofwboot.xcf, not
bootxx/ofwboot. installboot is only needed if you're using ofwboot/bootxx.
> ofwboot needs installboot to poke a sector number for the kernel in a
> "magic place".
No, bootxx needs installboot to poke sector numbers for ofwboot into it.
> Can OF still find the hfs part. containing ofwboot after installboot
> trashes the APM? If I don't run installboot, how do I complete the
I thought the hfs-only method was working on hfs partitions.
> I still don't see how I can get an unattended boot on a single drive unless
> I do something like leave a CD in the drive on OF 3.x machines. I could
> also simply have a second HD, but that's hard on a machine like an
> early model B&W G3 where the ATA bus doesn't work right if you try to attach a
> second drive.
> Am I way off here???.
You got ofwboot/bootxx intermixed with file system based booting, and thus
got confused. :-)
Not sure what to do about the autobooting, since I'd expect the hfs
partition method to work.
> P.S. I've seen the more recent posts about using dd to write raw partitions
> directly to parts of the HDD. I'm a wimp, and I want to avoid this
> sort of ..ahem... operation. ;->
If it's an otherise empty partition, should be fine.