> At 08:59 AM 4/15/00 , Anders Magnusson wrote:
> > > 
> > > Thanks.  Any idea why disklabel -B and booting doesn't work?
> > > 
> > >  >>> boot dka0
> > > 
> > > [several seconds pass...]
> > >   
> > > ?06 HLT INST
> > >    PC= 00000B15 PSL= 041F0004
> > > 
> >Not directly, but probably it loads the boot block and starts it, and
> >then later fails. Try to put in some "halt" in boot/xxboot/start.s and try
> >to figure out where it fails.
> 
> BTW, why don't the boot blocks just use VMB (aka rom()) to read the disks
> instead of having to have disk drivers in the boot blocks?  I know that VMS, ELN,
> and ULTRIX all used VMB to read the boot blocks and the kernel off the disk.
> I don't see why should do anything different...
>
Well, the boot blocks actually do use the VMB routines for reading the
boot program of the disk. The boot program (second-stage loader) do not
use the rom routines (unless rom() is specified) because it needs to be
more flexible than the VMB routines are. For example, if I loaded the
boot program from tape, I want to be able to specify qe()netbsd to load
the kernel from net. Ultrix can't do that, neither can VMB; it can only
load programs from the same controller as it booted.

-- Ragge