[coreboot] USB debug cables and emulation
patrick at georgi-clan.de
Fri Jul 4 03:44:18 CEST 2008
Joseph Smith schrieb:
>> We're pretty far with the UHCI stack in GRUB2. If you are looking for a
>> USB project to jump on, we can certainly use help ;-)
>> Initial keyboard support is there. MSC support is there, UHCI is there.
>> Missing: Fixes, Testing, OHCI, EHCI, Fixes, Fixes, Testing...
>> Maybe we can pack it into libpayload instead of GRUB2 too, so we can
>> make it available to more payloads?
It's clean code with no imports (though I got some clues from other
sources, esp. as far as workarounds for chipset bugs are concerned, but
it should be safe), so it's not bound to a license, and apart from
grub_strcpy here and grub_uint32_t there, which can be sanitized easily,
and some trivial pci controller detection logic, it's not very grub2
specific either. I merely develop it inside the grub2 tree because
that's the most convenient for now.
> Stefan, I would love to help out. I offered my services to Patrick a while
> ago, with no response.
> What can I do?
You seem to be only starting into USB now, but so did I when I started
writing this code (which probably shows at places). I quickly collected
- testing and fixes, lots of it
- make more clever (eg. bulk transfer with >1 packet/ms, which might be
done next week already)
- fix some abstractions (eg. bulk transfer is at the wrong place currently)
- improve interrupt transfer handling
- create driver (most of UHCI doesn't apply here, because the chip is
more clever. "fix some abstractions" definitely helps, though)
- figure out how to gain control over a device from the USB1 controller
(that will somehow interact with the USB1 driver)
- PING/DATA2 protocol, microframes support
- extend HUB driver, so it handles USB1 devices on a USB2 hub
- the keyboard driver is rather rudimentary
- mouse doesn't exist
- mass storage only likes few devices (high priority for me)
- hub driver doesn't have proper device power management yet
Get the code to run, figure out the design (sorry, no documentation yet
- but ask me. The code can only become better that way), play with it,
fix it for your hardware, ask questions, send/commit patches, ...
On my personal TODO (after this %!$# northbridge works for me) is most
of the UHCI stuff, and mass storage. Everything else is pretty much free
for grabs (but it might be good to tell me so I don't step on your
toes). OHCI and mouse are definitely not on my list for the short term,
other usb device drivers also aren't. I also don't mind patches to any
part of the code :-)
More information about the coreboot