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MUPDF/DGJPP test release! (Users)

posted by Ninho(R) E-mail, 23.02.2011, 17:19
(edited by Ninho on 23.02.2011, 18:20)

>> But then what's going wrong has to be the determination of the LFB
>> address and size. I understand you are querying the VESA BIOS, which on
>> this box provides a false answer

I had not had an incentive to look into this before, now digging a little further, (plain DOS) : VESA BIOS reports the LFB at C0000000h (3 Giga), and that is correct. But at the same time for some unfathomable reason AMI/SiS BIOS erroneously has pointed the appropriate MTRR (MSR 20E/20F) to phys address D0000000h instead of C0000000. "Plug and play" they say, let me laugh :=)

Correcting the MTRR "by hand" (thanks, o my faithful TD) leads to a 7-fold increase in video speed measurements, using the LFB.

I also tried to enhance video speed legacy bank switched modes by setting the appropraite "fixed range" MTRR at A0000 to "WC" type. Strangely, in this case I don't get any improvements from uncacheable to write combinable. Any idea why ?


> Yes, did you RTFH?
> SYNTAX: MTRRLFBE area mode

I try to RTFthings. I missed that, or I have another version of mtrrlfbe.


> Yes I read physlfbprt from VESA VBE info func. So it seems you have rare
> bug in VESA BIOS. What is other way to determine LFB address (that works on
> your PC)? What is your VGA? Does others programs work with LFB? I tested it
> on various VGA with different address of LFB and it was always detected
> OK.

The other way is taking the LFB address directly from the SiS 741 (north bridge) registers where it resides !

>> Anyway... I'm going to write my own tiny DOS proggie to enable WC on the
>> legacy video buffer - no need for DOS extended bloat in my book.

> You can save your work, Japheth already wrote an alternative (smaller code)
> utility according my advice. It's part of HX DOS extender (not HXRT but
> some other package).

I love to spare me work, in principle, unfortunately it all too often happens that others' work is lacking in one ore another respect <LOL> or in other words, that "one size fits all" is too good to be much more than a sales slogan :=)

Thanks for your efforts and cheers

---
Ninho

 

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