Xref: news2.mv.net comp.os.msdos.djgpp:630
From: jtsilla AT ccs DOT neu DOT edu (James Tsillas)
Newsgroups: comp.os.msdos.djgpp
Subject: Calling into a malloc'ed buffer
Date: 29 Jan 1996 14:55:28 GMT
Organization: Northeastern University
Lines: 24
Distribution: world
Message-ID: <JTSILLA.96Jan29095528@atlas.ccs.neu.edu>
NNTP-Posting-Host: atlas.ccs.neu.edu
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp


Hi, VBE 2.0 supports a protected mode optimization where you can copy
out driver code into your virtual memory and call into it to perform
certain video functions. Well, I've gotten this all set up and when I
try to call (via call (%eax) or similar), the debugger tells me I'm at
address 0x0 and I get a SIGSEGV. Is there anything I need to be aware of
when attempting to do this? Do I need to change permissions for my
memory segments to be executable?

BTW, I've gotten nearptr's to work on my linear memory using VBE 2.0.
Thanks to the folks who helped me on this one!

-Jim.
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