From owner-freebsd-hackers  Tue Mar 18 02:39:53 1997
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Subject: ep driver memory management question..
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Date: Tue, 18 Mar 1997 04:39:03 -0600
From: Chris Csanady <ccsanady@nyx.pr.mcs.net>
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I'm not very familiar with net drivers, but I would like to rewrite the ep
driver to use contiguous packet buffers.  I am curious about how it allocates 
memory for packets, and if there are any limitations.  From the code, it looks 
as if it just allocates an mbuf, dmas into it, and passes it off to 
ether_input.  Is this correct?  I thought that there was a 16M limit on dma 
for the isa bus without bouncing, but I didn't see anything that dealt with 
this.  Is this because all the mbufs get allocated at boot, so its just the 
way it turns out?  If so, I will need to allocate a contiguous chunk of memory 
for the driver upon boot.  How would I do this?

Thanks,
Chris Csanady