On Tue, 13 Jan 1998, David Brownlee wrote:
> On Wed, 14 Jan 1998, Brian D Chase wrote:

^
|
[interesting time zone oddity]

> > Argh. This would seem a bit more tricky to deal with.  (I need to remember
> > to grep the archives prior to opening my keyboard).  Is it that the kernel
> > by design locates buffers in high memory, or does one have flexibility in
> > where you locate them?  I guess my question is, does NetBSD have the
> > facilities to allocate buffers in physical memory where you please?  If
> > not, how do you get around this problem? 
> > 
> 	The kernel could allocate the buffers anywhere it chooses... :)
> 	It may have been cleaner or easier to allocate the buffers at the
> 	top of memory.
> 
> 	Hmm.. from a quick browse of /sys/arch/vax/ka43.c
> 	ka43_steal_pages() steals 64k from the top of available memory for
> 	the LANCE's (VS3100 ethernet chip) buffers. It has a note that if
> 	the address is over 16MB to set the 'LANCE DMA' bit which is used
> 	as an extra address bit, which _should_ mean it would work with up
> 	to 32MB, but still fail with more....

I don't know that the VS3100's support more than 32Megs so that might not
be a big problem.  Maybe the M76 supports more?

> 	I would be inclined to try modifying to code to steal the pages
> 	from avail_start rather than avail_end (there _has_ to be a reason
> 	why its not just that easy :),

Well that definitely sounds worth trying.  From what I can tell the one
reason which seems to plague the NetBSD/VAX port most often is "the lack
of time."  The developers who contribute to the kernel are top-notch, but
it seems like there's this general struggle to find enough free contiguous
hours in a day to get significant work done.

>       but I'm still not able to get my
> 	VS3100 running - I now have a serial cable from Brian (Thanks
> 	Brian!), but I've found out my genuine VT240 is a genuine non
> 	working VT240.. grr.. I'm sure I have a breakout cable for the
> 	serial port on my IPX, so I'm not beaten yet :)

[Hopelessly wandering at this point] Hey, I've got an IPC! Which isn't
quite as nice.  Those little Sparcs, they're so cute.  For the initial few
weeks of my first VS3100's life I used an Atari 520ST as a terminal.  It's
VT52 terminal emulation program worked quite well. In general I find a PC
running something like minicom or Telix to be a very good solution.  With
minicom I can pull the session up in an xterm, minding it out of the
corner of my eye while going about other tasks.  You've got to be careful
with them VAXen, they're a sneaky bunch.

-brian.
---
Brian "JARAI" Chase | http://world.std.com/~bdc/ | VAXZilla LIVES!!!