Very Computer

I've done a search on this topic and didn't find any definitive answers so
here's my dilemma...

We have Solaris 7 installed in 64-bit mode on an Ultra 10 (360MHZ).  I
discovered today that we need to drop back to the 32-bit version to support
the Solstice PPP 3.0.1 package that is currently being used by one of our
developers.

I want Solaris to auto-boot in 32-bit mode.  How should this be done in a
civilized manner?  I've gone through the man pages and answerbooks, but
nothing is spelled out.

I wondered about setting the boot-file param to /kernel/unix in OpenBoot,
but I'm really worried about doing that.  Can anyone tell me what files to
alter (if any) to set this machine up to auto-boot into 32-bit mode?

AC

 The solaris FAQ says:

 1.19) How can I boot a 32 bit kernel when a 64 bit kernel is installed?

    From the "ok" prompt, type "boot kernel/unix".

    Setting the "boot-file" in the EEPROM to "kernel/unix" makes it
    the default kernel.  Alternatively, you can move away the
sparcv9/unix
    file in which case the boot loader will fall back to the 32 bit
kernel.
    Patch installation may restore that file, though.

    Beware: when specifying "boot -s", the standard default
    kernel/sparcv9/unix kernel will be booted; you need to specify
    "boot kernel/unix -s".

    --- end of excerpt from the FAQ

isainfo -kv

Although you say you already know this!!!

The way I affected the change on my machine was to alter the boot-file, it
doesn't cause problems:

ok boot /platform/sun4u/kernel/unix = 32bit
ok boot /platform/sun4u/kernel/sparcv9/unix = 64bit

Or you can alter the /platform/sun4u/boot.conf. The final line in the file
looks like this:

ALLOW_32BIT_KERNEL_ON_UltraSPARC_1_CPU=true (this is what it reads on my Ultra
5).

However, the safest bet to get it to work is to change the boot-file argument
and leave boot.conf alone.
Sometimes, however, when booting from CDROM the machine can hit problems as it
can't find the boot-file to run. In this case, hit a stop-A (or init 0 if you
can), and:

setenv boot-file kernel/genunix

Let it boot from the CDROM (or whatever you are doing at the time), when you've
affected the changed you need to make set the boot-file back to the setting it
needs to be at for either 32 or 64bit. This is the only bugbear that I've found
with switching the bit values in Solaris 7.

Hope this helps.

Dan