Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!aramis.rutgers.edu!topaz.rutgers.edu!elkins
From: elkins@topaz.rutgers.edu (George Elkins)
Newsgroups: comp.sys.sgi
Subject: Re: Booting backup kernel
Summary: booting unix from PROM or sash
Message-ID: 
Date: 14 Aug 89 04:09:50 GMT
References: <1263@uvm-gen.UUCP>
Distribution: usa
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 24

In article <1263@uvm-gen.UUCP>, ackerman@uvm-gen.uvm.edu (Steve Ackerman) writes:
> 	Tonight, I accidently clobbered my Personal IRIS kernel.
> Fortunately, I had a backup of it in /unix.old.

You could use the boot command from either the PROM monitor level,
or from sash (stand-alone shell).  The boot command attempts to
boot sash, in both cases.  So when in sash, you must use the -f
option.  At the PROM monitor level you could type
	boot dkip(0,0,0)unix.old
or from sash you could type
	boot -f dkip(0,0,0)unix.old

The general format for the boot command from sash is:
	boot [-f device(address)file] [arguments]

You may need to modify the above for your particular device,
address and desired init level, etc.  E.g. from PROM,
	boot dksc(0,1,0)unix.old initstate=1
for scsi disk controller, putting machine into single-user mode.

(All of this is from memory, so it could be slightly wrong.  Also,
my experience is with Iris 4D.)

George Elkins