Sorry if this is old news. http://www.rockbox.org/mail/archive/rockbox-dev-archive-2011-10/0112.shtml
Ladies and gentlemen, we have sound on HiFiMan HM-601.
Gear mentioned in this thread:
It appears they have. I think the OP should alter the thread title to Rockbox on Hifiman players.
This actually makes me interested in a 602 or 801 now, with the former being a cheaper option than going for the iPod>CLAS>amp thing, which I confess I still want to do eventually. Actually the 801 would still be cheaper than that too. Definitely keeping my eye on this.