Supporting extension ROMs and beyond...

SONE Takeshi ts1 at
Sat Aug 9 13:01:01 CEST 2003

On Fri, Aug 08, 2003 at 01:51:16PM -0600, Eric W. Biederman wrote:
> > Of couse the DOS applications like EMM386 and things like DPMI 
> > won't run with a BIOS which does it's job in 32-bit.
> > And nowadays nobody uses those application.
> Dosemu which uses DPMI still has a surprising number of users.

I thought dosemu emulates all the BIOS calls itself, and never
calls the underlying real BIOS.

> I guess my preference would be to make a 16bit clean core that supports
> option ROMS and those options roms could be like etherboot and do the extension.

In my opinion, 16-bit code is never clean. :)
(except the case everything is in 64KB)

Even if using GCC with .code16gcc to make a realmode code,
the compiler knows nothing about segmentation, 64KB barrier...
so we have to take care of segments in all over the code.
"Flat real mode" (setting segment limits to 4G) is out of question
because it will not run in vm86 either.


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