zzmde wrote:
> Thank you very much. Can I write the code in user space? Or I have to
> write a kernel driver to reach the highest speed? What about the speed
> difference between user space and kernel space?
>
> Thanks,
> Zhaomin
Hi Zhaomin,
There is no difference in I/O speed between user-space and
kernel space.
When you map /dev/mem into the process (user-space) application,
the MMU is setup to map the XDIO to process addresses. If you
work in the kernel, you end up doing something similar to
get addresses mapped to the kernel.
The difference comes when you want to use interrupts, or want
to allow non-root users to access the hardware.
You're better off to get things working first, and then
decide later if you want to change things like users.
Cheers
Dave
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