Re: More on iSCSI boot

[Stephen Bailey <steph@cs.uchicago.edu>]

Just one nit.

> On Intel systems, it's generally a combination of the system BIOS
> and card BIOS that make the disk reads work.

It this really true in practice?  Once upon a time, it seemed like
card-specific BIOS extension were becoming deprecated.  Probably all
BIOSes still support BIOS extensions, but I don't think current
adapters actually provide them.

My understanding is that if you want to boot off a disk controller,
you either have to have specific BIOS support for it, or you have to
emulate/implement INT13.  This appeared to be conscious choice of the
platform (BIOS) vendors to only support a bounded set of boot
alternatives (since boot should be a bounded process) on each
particular platform.

If this is the case, it doesn't make sense to provide for iSCSI boot
on a platform that is not conscious of that choice.  This implies that
the resources available for iSCSI boot are the complete resources of
the platform's BIOS environment.

This doesn't seem to substantively change the discussion, but it does
remove one particular scenario from consideration.

Steph