One patch required is the file "ugen.c". In the function "ugen_open_pipe_read()",
find the line "case UE_INTERRUPT:" and then some lines further down you will find:
/* first transfer clears stall */
sce->read_stall = 1;
Chaneg this to "0".
Then recompile and install the "ugen" module and/or kernel.
Links to the FreeBSD USB Mailing List thread:
http://lists.freebsd.org/pipermail/freebsd-usb/2007-October/004057.html
The bootloader (bulk transfer) is not working yet.
http://lists.freebsd.org/pipermail/freebsd-usb/2007-October/004058.html