Subject: System hangs after BIOSCALL
To: NetBSD i386 Mailing List <>
From: Brian Clough <>
List: tech-kern
Date: 10/16/2001 11:31:30
I'm having a problem when I use BIOSCALL to call Int10, function 4F02 (Set VESA
video mode).  

If I call other VESA BIOS functions at boot or runtime) there's no problem, and if
I call Set Mode during initialization it works too.  Only if I call Set Mode at
runtime does the system hang.

Actually, after the call, the system continues for a short time then stops dead,
no error messages or anything.  I can output characters to the console so that's
how I know it's returning after the set mode call.  I do the actual BIOSCALL
inside an IOCTL in the video driver, then call the driver from an app.  I get back
to the app, but when I do get back I don't have long to live.

I've got an ICE connected to the system, and I can see where execution is hitting
a HLT, but how can I find the corresponding location in the source code?

Brian Clough
Phoenix Technologies
OS Development Group, Norwood, MA