Re: [9fans] these are release of 9front?

[cinap_lenrek@gmx.de]

how can it not interoperate with plan9 programs? the usb subsystem
in 9front just organizes the instantiation of userspace drivers
differently. the kernel hci drivers and interfaces are the same
(biggest difference is that we added buffer delay control for iso
endpoints for usb audio).

instead of embedding all usb drivers in usbd, we run them as
separate fileservers/programs using lib9p instead of a
usb-fileserver-driver-framework-factory.

to get these fileservers into a global namespace, we created a
device that lets one register global mount points. so when i plug
in my usb camera, nusb/ptp gets started and the cameras filesystem
appears under /shr/sdU1.2 ect. a lot of complexity can be removed
from the drivers when one has its own processes and not have to
worry about sharing memory and filedescriptors with everything
else. a crash in one driver doesnt bring all usb down and one
can just kill a driver and attach another one for debugging without
loosing the other devices or the hub.

in a way, this is just like the old usb stack worked. you just
have a small usb helper lib for common stuff like activating
endpoints and parsing descriptors and distinct programs for
drivers. to make it work for hotplug, you use the /shr instead
of /srv.

all this doesnt matter for programs using usb devices. the
filesystem interfaces behave the same.

--
cinap