OpenEuphoria

RE: Memory Question

• Posted by "Daniel Kluss" <xerox_irs at hotmail.com> Feb 15, 2004
• 565 views

How do I allocate the physical memory?


>From: CoJaBo <cojabo at suscom.net>
>Subject: RE: Memory Question
>
>
>I think this will work(I don't think it was tested on exw yet):
>
>
>en,
>
>I just happen to have some machine code that I wrote (for Neil gfx lib
>long ago) that will convert a physical address to an poke-able
>Causeway-friendly virtual address. In the code below, replace
>PhysBasePtr with your physical address, and the result video_mem will be
>
>the address that you can poke to.
>
>The machine code uses Causeway interrupt #31, function #19,
>"Linear2Near" - CONVERT LINEAR TO APP-RELATIVE ADDRESS
>(http://www.delorie.com/djgpp/doc/rbinter/ix/31/FF.html)
>
>Regards,
>Pete
>
>include machine.e
>
>-- code to convert the physical base address to the linear frame buffer
>address
>constant getlfb = allocate(86)
>poke(getlfb, {
>      #60,                    --    0: pusha
>      #8B,#1D,#52,#2B,#14,#02,--    1: mov ebx, [@linear]
>      #85,#DB,                --    7: test ebx, ebx
>      #74,#0C,                --    9: jz batman
>      #89,#D9,                --    B: mov ecx, ebx
>      #C1,#EB,#10,            --    D: shr ebx, 16
>      #B8,#01,#08,#00,#00,    --   10: mov eax, #801
>      #CD,#31,                --   15: int #31
>                              --   17: batman:
>      #BB,#00,#00,#00,#00,    --   17: mov ebx, PhysBasePtr (24)
>      #89,#D9,                --   1C: mov ecx, ebx
>      #C1,#EB,#10,            --   1E: shr ebx, 16
>      #BE,#00,#00,#40,#00,    --   21: mov esi, 4194304
>      #89,#F7,                --   26: mov edi, esi
>      #C1,#EE,#10,            --   28: shr esi, 16
>      #B8,#00,#08,#00,#00,    --   2B: mov eax, #800
>      #CD,#31,                --   30: int #31
>                              --   32: jc robin
>      #C1,#E3,#10,            --   32: shl ebx, 16
>      #66,#89,#CB,            --   35: mov bx, cx
>      #89,#DE,                --   38: mov esi, ebx
>      #B8,#19,#FF,#00,#00,    --   3A: mov eax, #FF19
>      #CD,#31,                --   3F: int #31
>      #89,#35,#52,#2B,#14,#02,--   41: mov [@linear], esi
>      #61,                    --   47: popa
>      #C3,                    --   48: ret
>                              --   49: robin:
>      #31,#C0,                --   49: xor eax, eax
>      #A3,#52,#2B,#14,#02,    --   4B: mov [@linear], eax
>      #61,                    --   50: popa
>      #C3,                    --   51: ret
>      #00,#00,#00,#00})       --   52: linear: dd 0 (82)
>poke4(getlfb + 3, getlfb + 82) -- @linear
>poke4(getlfb + 67, getlfb + 82) -- @linear
>poke4(getlfb + 76, getlfb + 82) -- @linear
>
>
>poke4(getlfb + 24, PhysBasePtr) -- convert physical base address
>call(getlfb)                     -- to linear frame buffer
>video_mem = peek4u(getlfb + 82)
>
>
>Daniel Kluss wrote:
> >
> >
> > (in dos or win dos box) Does anyone know a good to allocate memory, and
> > get
> > the PHYSICAL address as well as the LOGICAL address, so system hardware
> > can
> > read/write and EUPHORIA can read/write. The only memory space I can find
> >
> > that does that so far is the allocate_low() which the PHY=LOG, but I
> > want to
> > allocate more than 1MB.
> >
> >
>
>
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