OS X High Speed Status


#1

There has been talk of some code to get high(er) speed USB under OS X.
Has any of this code made it into the CVS tree yet?


#2

Yes, there is code for higher speed USB 2.0 on OSX. On a Dual G4 @
1.25 GHz with a $15 drop-in USB 2.0 card, I can get just over 30
M-Bytes/s read and 28.5 MBps write. Not the 32 MBps which I would
really like, but it’s about as minimal an implementation as I can get.

No, it’s not in CVS yet. It currently requires OmniThreads, which is
compiled into gnuradio-core, which the USRP cannot directly require or
link to without some non-standard hacking. The compiled library will
work properly so long as gnuradio-core is available in the dynamic
library path, which means it’ll work for pretty much any GNURadio
python script. But applications must be linked with both libraries
(usrp and gnuradio-core) - e.g. the test apps provided in the USRP
source code.

The “fix” is either to (1) move the OmniThread package outside
gnuradio-core into its own library (installed in $prefix/include
instead of $prefix/include/gnuradio); or to (2) move to OSX-specific
threads to avoid the linking issue entirely.

OR, (3) the better option but also the most difficult would be to move
the whole of USRP’s LIBUSB’s function calls into the fusb_<> classes,
which would then either call LIBUSB or do it itself. I would love to
do this one, but it’ll be complicated and time consuming both to figure
out what to do as well as to test it on all platforms.

I am happy to provide a tarball with instructions to any OSX user who
wants to try it. Just send me an email. Sooner or later it’ll be
posted on our WWW site < http://sdr.nd.edu >. - MLD