> It would be nice to support multibooting NetBSD and

That rather depends on whether Legato used the same codebase and
compatible structures ondifferent hardware platforms.  If they didn't,
this isn't very workable -- it'd mean per-platform code to read and
write a PrestoServe board, at best.

>(Why would you make them consistent, and not simply
>have them be a convenient format for that native OS?)

It's not implausible for different OSes (e.g., *BSD and SunOS) to be
sharing the same filesystems.  If they do, and the curernt data is
actually in the PrestoServe board there are potential consistency
problems.

My primary concern is wethher or not the vendor OSes force dirty data
in the NVRAM to disk when they shutdown or reboot or panic. If they
don't, there's a potential for inconsisency and dataloss for any
reboot that ends up changing the OS -- possibly accidentally.

Whether you think this is worth worrying about depends on how many
people with PrestoSevre-aware vendor OSes would want to multiboot
NetBSD on that same hardware.  Given that we don't currently support
PrestoServe, a high fraction of the people out there who have
PrestoServe hardware might not be running NetBSD and may want to
initially multiboot NetBSD and <vendor OS> to convince themselves
things really work.

Sure, this terribly likely in the scheme of things; but I think
_anything_ where NetBSD design could be blamed for the loss of user
data should be avoided.