zero_copy in RTEMS
gds at chartertn.net
Tue Dec 23 20:27:57 UTC 2008
朱旭峰 wrote, On 12/22/2008 04:59 AM:
> Thanks for your reply, both.
> I looked for some information about zerco copy from the
> internet, and it said that the zero copy is trying to avoid the data
> copy between the kernel space and the user space, but the memmory space
> is flat in RTEMS, that is to say there is no difference between kernel
> space and user space.So I wonder is that possible to realize zero copy
> in a network interface card driver, and if there is, how to realize it
> ,is there some source code which I can look up into?I didn't find
> Coldfire FEC and the EMAC you amentioned in the RTEMS source code.
> Thanks again.
I think Chris answered your primary question quite well. I will answer
your question about EMAC. The EMAC controller (I think it was called)
for IBM ppc405gpr I worked on several years ago experimentally. I know
my code is not in RTEMS. I originally found the code in NetBSD I think.
You can probably still find it on their CVS site. Not sure that the
license is 100% OK with RTEMS (advertising clause and other reasons).
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