On Sat, 31 May 1997 14:05:53 -0400 (EDT) 
 Paul Evans <paule@shadowfax.martex.GEN.OH.US> wrote:

 > This is one of the few things I always found attractive about LILO: dosen't
 > this allow chain-booting to another loader or OS -- without having to
 > know the details of it?

...any generic boot slector (like OS-BS) can do this.  But, loading your
kernel this way is Just Wrong(tm).

Of course, certainly you have to know the details of the kernel you're
loading, because you have to pass the proper arguments, load the
correct file format, symbols, etc.

 > Maybe for the VAX this is inconvient, but because LILO is PC based I
 > think it does it's job quite well. Although not as well as the Solaris x86
 > boot loader.. (MDB ? I think?)

For _any_ architecture, LILO-like functionality is inconvenient.  The
ability to select multiple OS boot loaders is a totally separate issue
from loading the kernel, and the way LILO loads the kernel just sucks :-)

Now, to be quite honest, I think BSD/OS has done a fine job with their
boot loader.  Some of the features appear in NetBSD/i386's new boot program,
which should be coming on-line pretty soon.

For the VAX, the boot loader just needs to be able to load the kernel
(in whatever format the kernel is in ... now, a.out .. future, Elf? I'm
hoping to write a generic Elf boot loader for NetBSD's libsa sometime
soon; already, a couple of platforms use a very similar version, alpha
and powerpc, and I want to start playing with Elf on the m68k).  You need
to be able to select alternate kernels, and possibly get a file system
listing.  Loading the kernel from disk or tape would be nice, and you
need to be able to pass in the boot device and boothowto in a sane
way.  Passing in the name of the booted kernel would be cool, too, but
it sugar, really.

 > Anyway the feature I'm always missing on non-sun3 machines is the ability
 > to do some fairly rudimentry hardware checks. I know DEC's pmax machines
 > have almost decent boot strapper that does this, but what about the VAXen?

...err, this is in the PROM, and it separate from the boot loader.

Ciao.

Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                               Home: 408.866.1912
NAS: M/S 258-6                                          Work: 415.604.0935
Moffett Field, CA 94035                                Pager: 415.428.6939