Re: more VXT2000 stuff

On Sat, Dec 21, 2002 at 11:27:52PM +0100, Anders Gavare wrote:
> Hello.
> 
> I have borrowed a VXT2000 model VX20A-AA, and, of course, it is slightly
> different than my VX20A-CA.  First of all, it has a memory hole; there
> is no region of memory 200000-3fffff. This is unfortunate, because the
> boot program is relocated to somewhere in that region.
> 
> Changing RELOC=0x39F000 in sys/arch/vax/boot/Makefile.inc to something
> else which is actually in an existing memory region, for example
> 0x3d000, solves that problem.  (Why is the address 0x39f000 the default
> value?)

To make room for the kernel...

> 
> (The -CA loads the MOP image at 0xd000, the -AA at 0x400a00. This should
> probably not matter.)
> 
> Then there is the problem again with console output.  (Maybe I should
> emphasize that I'm not using a _serial_ console.  I'm using keyboard +
> monitor as my console.)
> 
> Using rom routines, 20040058 is putchar, and 20040044 is a non-blocking
> getchar, just as on my VX20A-CA.  With these routines, the boot program
> runs, detects ethernet and does all the rarp + nfs stuff.  (Compiling
> the kernel seems to work up until the final link. Then it fails. So I
> don't know how far it would make it inside the kernel.)
> 
> Ragge's putchar/getchar doesn't work on either of the two VXTs I have
> tried.  (One possible explanation could be that Ragge is using serial
> console. (??))
> 

Well that's probably the issue then.. If the VXT has no rom support
for serial console then ragge's work has presumably been to drive its
serial device directly.

> However, if I change the line
> 
> 	static volatile int *vxtregs = (int *)0x200A0000;
> 
> in .../vax/boot/boot/consio.c to 0x200A0040 instead, I can read data
> from the keyboard, but the values returned are keyboard scan codes and
> not ASCII values.
> 
Two sets of rom routines, one for console and one for serial, but with
more mangling required for serial support? I can see why people have
given up on the rom and just gone talking straight to the VXT's UART.

Brandon at one point did this for DZ when we were having problems with
certain machines, but we worked them out another way and were able to
stick with the rom. And unfortunately as ragge's pointed out, the VXT
uses a SC26C94 UART rather than the usual vax DZ-alike.

In general we've put any hopes of framebuffer support for the common
vaxstations way down on the wishlist, since our various efforts to
turn up documentation have been so far fruitless, so it may be just
as well to concentrate on getting serial console working instead.

/Hugh

> 
> 
> Anders