Subject: Re: Secondary Boot
To: port-sparc <port-sparc@netbsd.org>
From: Andy Ball <andy.ball@earthlink.net>
List: port-sparc
Date: 05/22/2004 04:14:55
Hello,
dM> No, it almost certainly wants the PROM path, something
> like /iommu@f,e0000000/sbus@f,e0001000/espdma@f,400000
> /esp@f,800000/sd@0,0 (this is the actual PROM path for
> the root disk (not a CDROM) on one of my machines). If
> you watch the messages produced by the ROMs before the
> NetBSD bootloader starts, you probably will see a path
> of that general style among them - that's probably
> what you need. (It will likely end with something like
> "sd@6,0" for a CDROM at ID 6.)
I didn't spot anything like that at boot time, and wasn't
able to make that format work for me. Happily I was able to
boot from a diskette and launch the rest of the installation
from the CD-ROM.
[Interesting & helpful stuff included from SILO thread]
dM> When you tell the machine to boot (perhaps
> implicitly), you must tell it which partition to boot
> from (though this is often defaulted). The ROM code in
> the machine reads the first sector of the disk. This
> is the pack's label, and in particular it contains a
> partition table.
Is the label's format specific to Sun firmware, or is it a
part of BSD or Unix common heritage? I ask in part because I
am wondering about interoperability of data disks (such as a
Zip disk that I labelled yesterday) between various ports
(at present I'm running NetBSD-1.6.2/sparc and /i386). How
many partitions can I define in a /sparc disklabel?
dM> The ROM code then reads sectors 1 through 15 of the
> partition you're booting from (skipping sector 0,
> presumably in case the partition begins at offset 0,
> since in that case sector 0 is the label sector). The
> 7½K of data read from the disk is dumped into memory
> and called.
Are the first 16 sectors of every partition reserved or just
those partitions that are bootable?
- Andy Ball.