Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!bbn!gatech!gitpyr!stat!curci
From: curci@stat.uucp (Ray Curci (scri))
Newsgroups: comp.os.minix
Subject: Passing pointers using callm1() (sendrec())
Message-ID: <7575@pyr.gatech.EDU>
Date: 14 Mar 89 01:57:17 GMT
Sender: news@pyr.gatech.EDU
Reply-To: curci@stat.fsu.edu (Ray Curci (scri))
Organization: Dept. of Statistics, Florida State Univ.
Lines: 12

I have written a minix device driver that sends packets of data between
minix machines.  The send and receive routines attempt to pass a pointer
to a buffer using M.m1_p1.  The problem is that when the device driver
receives the message, the pointer appears to be relative to the caller's
data or stack segment.  To get at the buffer of data I have tried using
many combinations of proc_addr(), umap(), and phys_copy() without success.
Can anyone send me a simple example of how to do this?  For starters, I
am simply trying to have my task copy the user's buffer into my own
local buffer.  I will post a summary of responses to the newsgroup.

ray curci
curci@stat.fsu.edu