[OLPC-devel] Re: belt and suspenders...

[Richard Smith]

> At the same time, what you are proposing could be generally very useful,
> even outside the domain of OLPC, and you could well prove me wrong -- I
> don't want to discourage you from trying it!

I've currently done this.  Its not releasable though. :(

A product that Bitworks is going to be trying to sell soon has a
custom USB stack that I wrote for the OpenCores USB 1.1 controller.
It only does mass storage.  I think it took me about a month.  A
simple implementation isn't really that hard (once you grok the
spec(s) )  but it doesn't stay simple for very long.    _Especially_
with USB mass storage, there are a lot of variations in the way the
"standard" was implemented.  Many of those devices are very picky
about how you talk to them.

I've only briefly looked at the OHCI, UHCI & EHCI controller specs but
I believe those controllers are a bit more complex than the embedded
OpenCores controller.

That said I agree with Ron that it would be very useful if such a
beast were to emerge.  There is on ongoing discussion in Linuxbios
about what to do for newer mainboards that don't have any serial ports
on them.  There's no way to output our debug info.  EHCI is said to
have some debug port but nobody seems to know how well (or if) it
works.

Limited resources are best spent elsewhere I think.  BUT if someone
does start working toward this I'll be glad to help.  I also have a
hardware protocol analyzer that's really handy in figuring out why it
doesn't work like you think it should.

-- 
Richard A. Smith