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Date: Mon, 19 Jan 2004 17:38:28 -0500 (EST)
From: Anand Subramanian <anand@pythagoras.math.uwaterloo.ca>
To: freebsd-hackers@freebsd.org
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Subject: mmap() on pseudo device
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Hi,
I am trying to share some memory between a networking daemon and the
FreeBSD 5.1 kernel. I am trying to implement the shared memory using a
pseudo-device via the make_dev() call. "mknod" at the command line prompt
no longer seems to work(no longer supported because of the devfs
interface? - it would be great if anyone could confirm this).


My questions :

1. I'm creating a pseudo device and having a user space process mmap() the
device memory into its address space. So the mmap for the device has to be
implemented. Are there any useful driver/source files I could look at for
this?

2. How can I access the mmaped memory from another kernel loadable module?

3. For the user space program, after it does a mmap() on the
pseudo-device, is there any way it can force malloc() to operate on the
mmaped memory? Or am I forced to write my own lightweight memory manager?
Most of the memory managers around seem to be way too complicated to
quickly fix or customize for a simple need.


TIA,


            Anand