According to Drew Northup ([EMAIL PROTECTED]):
> Ok, thanks........ What then provides the support for text-only OS support?
> (For OS's without a terminal driver......)
Sorry to just kick in, but maybe the following could work:
+----------+ +----------------+
| VGA BIOS | | special driver |
+----------+ +----------------+
- -V- - -V- - - -|- -|- - -|- - -
+----------+ | | |
| VGA emu | | | |
+----------+ | | |
V V V V V
+-----------------------------+
| display code in user |
+-----------------------------+
Here, the main example of the special driver would be that it bypasses the
VGA emulation (which is using hardware traps for detecting screen writes or
something), and thus can optimize for some special cases (window moving,
plane filling... about anything the guest os would allow it to optimize for).
Programs using the VGA BIOS (or the VGA I/O ports for that matter) would
simply get emulated by the VGA emu. This would be valid for both text as
well as graphics modes.
An implementation could involve emulating some VGA card by listening on it's
I/O ports and doing whatever is expected, and have the special driver
redirect it's requests to another I/O port or something.
Wouter
--
* Wouter Coene * [EMAIL PROTECTED] * [EMAIL PROTECTED] *
* C.O.R.E/OMTA/Plex86 * C development/Code maniac *
* "When people run in circles we call them crazy, *
* when planet's do we call it orbiting" *
