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MUPDF/DGJPP test release! (Users)

posted by RayeR(R) Homepage, CZ, 23.02.2011, 13:17

> Yes, binary compatible MSRs starting with K7 (at least Athlon XP; am
> not certain about old plain Athlons) Previously K6/K6-2/K6-3 had their own
> incompatible mechanisms for write allocate, write combine and like
> stuff...

OK, then it should work.

> 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 :=) Does the your program allow for
> user-provided address and size ?

Yes, did you RTFH?
SYNTAX: MTRRLFBE area mode
area: "VGA" or "LFB" (address range to apply mode change) or
"USER:base_address:size" (base_address is a hexa-number, size is in kB)
mode: "UC" - UnCached, "WP" - Write-Protected, "WT" - Write-Through,
mode: "WB" - Write-Back, "WC" - Write-Combining

> From bare DOS, using turbo debugger, I've just checked the MTRRs as set by
> the BIOS. The range intended for video LFB appears to be 32 Megabytes at
> D0000000h, which are properly set in a pair of phys_MTTRRs as "type 01"
> memory (WC). But according to your program (and VESATEST) the VESA BIOS
> tells the LFB is at C0000000. Moral : don't believe VESA !

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.

> 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).

---
DOS gives me freedom to unlimited HW access.

 

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