On Sun, 14 Jan 1996 23:00:41 -0500 (EST) 
 raub@kushana.aero.ufl.edu (Mauricio Tavares) wrote:

 > options 	HAVECACHE		# Sun3/260 VAC
 > 
 > 	Do I need this one with my 3/50?

Nope.  It only makes a difference on the 3/260 (or 3/280).

 > # XXX - Work-around for root on slow SunOS/Sun3 servers (sigh...)
 > options 	NFS_BOOT_RWSIZE=1024
 > 
 > 	What exactly is this supposed to do?

It tells the NFS boot code (if your system is diskless) to use smaller 
packets so that slow *servers* can cope with it.

 > # Sun3-specific debugging options
 > #options 	CONTEXT_DEBUG
 > #options 	PMAP_DEBUG
 > #options 	VMFAULT_TRACE
 > #options 	SYSCALL_DEBUG
 > #options 	EXEC_DEBUG
 > options 	DIAGNOSTIC
 > options 	SCSIDEBUG
 > 
 > config		netbsd swap generic
 > 
 > 	What are they supposed to do, especially the commented out ones?

The commented-out ones enable debugging code in their respective areas of 
the kernel, as does SCSIDEBUG.  DIAGNOSTIC is a system-wide option that 
places additional sanity checks in various places.  I usually only run 
with DIAGNOSTIC.

The "config ..." line configures root/swap/dump in your kernel.

 > # Intel Ethernet (onboard, or VME)
 > ie0 at obio0 addr ? level ?
 > ie1 at vmes0 addr 0xffe88000 level 3 vect 0x75
 > 
 > 	Do I need this one?  As far as I know I do not have ie... do I?

Right ... a 3/50 only has the LANCE.

 > # Lance Ethernet (only onboard)
 > le0 at obio0 addr ? level ?
 > 
 > 	What is the "?" supposed to do?

The "?" is a wild-card.  It allows the system to use a default address.  

 > # The default cgfour address depends on the machine:
 > # 3/60: obio 0xFF200000 .. 0xFF9fffff
 > # 3/110: different? (not tested)
 > cgfour0 at obmem0 addr ?
 > 
 > 	I do not have cgfour, do I?

No ... a 3/50 only had a bwtwo.

 > # The default bwtwo address depends on the machine:
 > # 3/50: obio   0x100000
 > # else: obio 0xff000000
 > bwtwo0 at obmem0 addr ?
 > 
 > 	How should I set this chap up for my 3/50?

That's just fine.  The bwtwo location is machine-dependent; it's 
different on a 3/50 than a 3/60, for example.  This "?" allows the kernel 
to pick the address appropriate for the system you're running on.

--------------------------------------------------------------------------
Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                               Home: 408.866.1912
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