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Date: Sat, 27 Feb 1999 22:39:42 -0500
To: djgpp AT delorie DOT com
From: Paul Derbyshire <pderbysh AT usa DOT net>
Subject: Re: Generating Machine Code on the fly
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 <199902261912 DOT OAA24117 AT envy DOT delorie DOT com>
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Reply-To: djgpp AT delorie DOT com

At 01:12 AM 2/26/99 -0000, you wrote:
>>This is exactly what the stub does :-) so it should work for you.

And the Allegro compiled sprites.

>Really? I can malloc 200mb and jump around within that code to my hearts
>content? How? Surely I'd have to write my own flat memory mapping code?

No, the asm runs in protected mode with the same flat memory access as your
C code. The memory management is taken care of by the virtual memory
management, which is CWSDPMI or Winblows in DJGPP and on Linux would be a
kernel component. The virtual memory management uses hardware features of
the i386 and later 32 bit chips to do address mapping and to trap access to
a linear address that's not physically present and invoke a disk swap,
transparently suspending your C/C++/asm code until the swap completes and
the memory is present, then letting it resume none the wiser.

-- 
   .*.  "Clouds are not spheres, mountains are not cones, coastlines are not
-()  <  circles, and bark is not smooth, nor does lightning travel in a
   `*'  straight line."    -------------------------------------------------
        -- B. Mandelbrot  |http://surf.to/pgd.net
_____________________ ____|________     Paul Derbyshire     pderbysh AT usa DOT net
Programmer & Humanist|ICQ: 10423848|