On 2010-8-8 2:24 PM, Blue Swirl wrote:
[...] The problem is that some images don't have a bootable partition in 'd', but 'a', any of these fail because only the first device is attempted in boot-device list. The automagic partition change hack may mask this.
[...] In the NetBSD case, 'a' is not bootable but 'd' is. Aurora 1.0, Zoot (Red Hat Linux 4.0) and SuSE 7.3 only boot from 'a'. In some images (for example Debian 4.0R5) 'a' and 'd' are equivalent
Some history behind the boot partitions - if you look at the man page for mkisofs, under the -sparc-boot switch, you'll see the various partitions which were reserved for particular architectures. My recollection is that partition ":d" was for the "dragon" architecture, from about 15-20 years ago. The current generation of SPARCs use partition ":f" (and have for at least a decade), although we may be changing that to ":a" fairly soon.
Current Sun/Oracle release DVDs are created such that all eight partitions point to the same physical blocks. You can boot from any of ":a" through ":h", and Openboot will be equally happy.
Solaris itself isn't quite as flexible. The common label parsing code does a bunch of geometry checks on the partitions, and unless it identifies the disk as a read-only removable media, will completely discard the label and return a "default" VTOC where only partitions 0 and 2 (:a and :c) exist, and they occupy the entire disk. This will matter to you only if you get pretty far into booting Solaris.