[vmips] bug in VMIPS

[Brian R. Gaeke]

> Hi ! VMIPS is wondeful ! Here is my 1 cent. All following writen for v1.2.
> Today i found v1.2.1, but quick view in new sources show what these features
> does not changed.

Hi Vladimir,

I'm glad you like VMIPS.  It's great to get constructive feedback!

> 1) When unknown to VMIPS option specified on command line, VMIPS call
> fatal_error(), which in turn cause core dumping. IMHO invalid command line
> parameters shoud not cause core dumps.

Yes, you have a good point. I had partially fixed this on the 1.3
(mainline) branch, but I found a few other cases. I merged these
fixes into the 1.2 (stable) branch.

> 2) Debugging with gdb is broken: 
> [patch omitted]

Whoops! Thanks for catching this. I've applied the patch, and merged
it into the 1.2 (stable) branch.

If you want, you can pull the vmips-1_2-branch from anonymous CVS
and you can get the updated sources. Or I can send you a patch
relative to 1.2.1. I'll probably try to make another 1.2.x release
in about 3 weeks.

> 3) Configuration defaults for VMIPS and XMBOOT are different. It's can be
> confusing for newbies trying to play with VMIPS and XMBOOT (yes, it's about me
> :) Default serial port for VMIPS is SPIM compatible console, but for xmboot
> default is DEC serial (serial.c). RAM sizes are different too (boot.script and
> boot_setup.S)

I'm sorry xmboot isn't very user-friendly. It's true that it has
to be tweaked a little to work with the default configuration, but
that's because I'm mostly testing the DEC devices these days, and
I use the "vmipsdec" script.

I haven't really thought about it much, but perhaps xmboot should
support auto-configuration (at least of memory size and serial port
type.)  I think that xmboot will tolerate any RAM size >= 16MB, at
the moment.  If you have any suggestions, I'm interested to hear them...

-Brian