Date: Wed, 6 Jul 1994 16:58:23 +0800
Subject: Re: promif questions

All sun4c machines have both 1.x and 2.x proms available for them.
The SS1, SS1+, IPC and SLC all shipped initially with 1.x only PROMs.
Upgrades are available for 2.x PROMs for these machines, so several
customers have them.

SS2, IPX, ELC all shipped with 2.x PROMs.  No 1.x proms are available
for these machines.

Then there's a hybrid prom, one that can behave in both 1.x and 2.x mode,
depending on an nvram variable.  I think it's 1.7 proms that have
this feature.

All sun4e machines have 1.x only proms.
All sun4m's and sun4d's have 2.x only proms.

>   If so, it seems we're stuck with the run-time switching unless we
>   have some sort of front-end program that figures out which type of
>   proms you have and loads the correct program (doubt it's worth it).

Yes, I think we're stuck with run-time switching for sun4c's until
we can EOL the early 1.x only sun4c's.  Don't hold your breath. :-)

>3) What is OBP_V0? Does it go away?

There are two notions of OBP version.  OBP 1.x, 2.x and 3.x.  These
numbers are the OBP version numbers visible to the user, that the user
sees using the banner command.  There is also a way to get at the
version number, programatically.

The other version number is the romvec version number, the version
number in the romvec, exported by the PROM giving the version number
of the client interface.  Currently we have 3:

romvec_version == 0; Is equivalent to a sun4c or sun4e 1.x prom.
romvec_version == 2; Is equivalent to a sun4c 2.x prom
romvec_version == 3; Is equivalent to a sun4m or sun4d 2.x prom.

romvec_version 3 proms have all non-sun4c specific client interfaces
plus the MP interfaces defined.  romvec_version 2 proms have a
sun4c/4e specific client interface (set_cxsegmap, I think) without any
MP interfaces.
