From:	"Andrew Davidson" <andrew AT lemure DOT freeserve DOT co DOT uk>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Generating Machine Code on the fly
Date:	Fri, 26 Feb 1999 01:12:29 -0000
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To:	djgpp AT delorie DOT com
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DJ Delorie <dj AT delorie DOT com> wrote in message
news:199902261912 DOT OAA24117 AT envy DOT delorie DOT com...
>
>> Is it possible to allocate an area of memory in djgpp using malloc,
>> fill it full of bytes of machine code, and then, using an asm
>> statement, push all the registers, call the area of memory as a
>> subroutine, pop all the registers when that subroutine returns, and
>> continue running the C program without any damage being done?
>
>This is exactly what the stub does :-) so it should work for you.
>
>Of course, getting the machine code *right* might not be trivial.
>
>> I assume that there would be some kind of limitation on the quantity of
>> machine code that could be run in this way?
>
>You're limited to a few hundred megabytes, probably.  Depends on how
>much memory you can malloc.

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?

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