On Thu, 2013-08-29 at 09:40 -0700, Andrew Fish wrote:
> There are a few issues. 1) From a security perspective SMM is locked
> at this point and you can't add SMM drivers. Why is this important?
> Well BIOS/DOS assume a PS/2 keyboard controller so for USB keyboards
> the BIOS typically has a USB stack running in SMM that stuffs data
> into/out of the keyboard controller. I'm not sure if SeaBIOS has a non
> SMM scheme for this?

I don't think it does. It has USB support, and should manage to provide
keyboard support via the BIOS interface for that, but if you really have
no PS/2 controller then I don't think it can emulate one.

It *does* have basic SMM support but as you say, it will be locked down.
And it doesn't have the fake-PS2 support to run in SMM; just the
infrastructure for SMM stuff to be added.

>  Then there are problems with getting the hardware into the correct
> state. Like needing a BIOS Option ROM  to get the video controller in
> VGA mode (DOS code can poke the video memory directly). 

Well, if your app really assumes VGA hardware and was broken with
EGA/MDA/etc then yes, that'll suck. But if you have a proper video BIOS
for the hardware, or if you can just use ask UEFI for a linear
framebuffer and then provide INT 10h services using that, you may be
able to achieve something useful.

> > I suppose there will be people who say it can't possibly be done. But
> > they told me that about SeaBIOS-as-CSM too :)
>
> Never say never. A simplistic bare metal VM on top of EFI with SeaBIOS
> in it might be more portable than trying to make a platform agnostic
> CSM.

Or dosemu under Linux, etc.

-- 
dwmw2

Attachment: smime.p7s
Description: S/MIME cryptographic signature

------------------------------------------------------------------------------
Learn the latest--Visual Studio 2012, SharePoint 2013, SQL 2012, more!
Discover the easy way to master current and previous Microsoft technologies
and advance your career. Get an incredible 1,500+ hours of step-by-step
tutorial videos with LearnDevNow. Subscribe today and save!
http://pubads.g.doubleclick.net/gampad/clk?id=58040911&iu=/4140/ostg.clktrk
_______________________________________________
edk2-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/edk2-devel

Reply via email to