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[rtl] Using DMA
Hi to all,
for those who don't know me yet have a look at the end of this message
for all the others:
How can I allocate memory for a DMA transfer from a device to the memory
of my computer?
I've found the function __get_free_pages() in kernel/mm.h. Shall I use
this one? If yes, how?
Everything shall happen in the kernelspace.
At the end I need a specified array of memory and a pointer to to first
element. But AFAIK DMA memory has to be somehow organized in 64 kB or
128 kB blocks of memory.
If this is a FAQ please point me to the documentation. I havn't found
anything in the Kernel Hackers Guide that would help me.
Thanks a lot,
Lucky
introducing myself:
I'm studying production engineering at the University of Bremen
(http://www.produktionstechnik.uni-bremen.de) in germany. I'm working at
the BIAS (http://www.bias.uni-bremen.de) a research institute in the
field of laser systems engineering,
I'm developing a real-time PID Controller for a laser hardening process.
All those who know the discrete equation for PID controllers know that
the time between 2 measurements is very important and has to be the
same. Therefore we've choosen to use a RTOS. We decided to use RT-Linux
because it offers more (for us) than QNX or LynxOS (and because I'm a
very big Linux fan :-). Windows was out of the question.
My knowledge of programming in C was very low (and still I'm not a guru)
but RT-Linux helped me to improve it a lot.
At the moment I'm fighting with my DT2821 (yes I've looked at the comedi
project :-) card from Data Translation. When finished writing the driver
I will help you in the documentation project in the sector of writing
device drivers under RTL. But first I have to finish my project here....
BTW. I would like to say 1 Mio. times thank you to Michael, Victor and
all the others who made RTL reality!
Sorry for my english in this message and all those that will follow.
--
----------------
lucky@uni-bremen.de
************************************************
* In an open world without walls and fences *
* who needs Windows and Gates? *
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--- [rtl] ---
For more information on Real-Time Linux see:
http://rtlinux.cs.nmt.edu/