Is using vm86 really a good idea? BeOS won't support it very easily due to
the kernel memory mapping. OS/2 already uses it for Windows 3.1 support.
NT doesn't use it because Microsoft feels its too buggy. (WOW in Windows NT
is a 32bit Windows App.. not virtual86 mode). Would this cause
complications with Dosemu in Linux? Just some thoughts.
Nick
----- Original Message -----
From: "Kevin Lawton" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, July 26, 2000 9:24 PM
Subject: plex86: running real-mode code in monitor v86 mode
> All,
>
> While I'm at it, figured I might as well add the beginning to
> running guest real-mode (RM) code in the monitor using
> v86 mode. That brings up some issues on that front to discuss.
>
> The first is whether to pre-scan RM code pages. Ideally it
> would be nice not to bother. But of course, the good people
> at Intel created some less-than-perfect virtualization, even
> of real-mode via v86 mode. For instance, the classic
> v86 mode detection code:
>
> SMSW some_word
> if (some_word & 0x0001) // CR0.PE==1
> in_v86_mode = 1;
> else
> in_v86_mode = 0;
>
> Perhaps it makes sense to ultimate have an option to run
> without prescanning (SBE) for code which doesn't encounter
> stuff like this.
>
> At any rate, what other cases like this will cause trouble?
> Anything that generates an exception when in v86 mode is OK,
> even if it wouldn't in RM.
>
> -Kevin
>
>
