path: root/src
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authorJulius Werner <jwerner@chromium.org>2013-09-17 22:16:04 -0700
committerIsaac Christensen <isaac.christensen@se-eng.com>2014-09-04 01:59:15 +0200
commitd13e2c4ab769e526e6b2c0ae568bd84b34688c58 (patch)
treecfe914006c840264d6a1ca97004c7aecf250ab96 /src
parente231de2134440eedb00136a5a373480c5d4ec209 (diff)
libpayload: usb: Refactor USB enumeration to fix SuperSpeed devices
This patch represents a major overhaul of the USB enumeration code in order to make it cleaner and much more robust to weird or malicious devices. The main improvement is that it correctly parses the USB descriptors even if there are unknown descriptors interspersed within, which is perfectly legal and in particular present on all SuperSpeed devices (due to the SuperSpeed Endpoint Companion Descriptor). In addition, it gets rid of the really whacky and special cased get_descriptor() function, which would read every descriptor twice whether it made sense or not. The new code makes the callers allocate descriptor memory and only read stuff twice when it's really necessary (i.e. the device and configuration descriptors). Finally, it also moves some more responsibilities into the controller-specific set_address() function in order to make sure things are initialized at the same stage for all controllers. In the new model it initializes the device entry (which zeroes the endpoint array), sets up endpoint 0 (including MPS), sets the device address and finally returns the whole usbdev_t structure with that address correctly set. Note that this should make SuperSpeed devices work, but SuperSpeed hubs are a wholly different story and would require a custom hub driver (since the hub descriptor and port status formats are different for USB 3.0 ports, and the whole issue about the same hub showing up as two different devices on two different ports might present additional challenges). The stack currently just issues a warning and refuses to initialize this part of the hub, which means that 3.0 devices connected through a 3.0 hub may not work correctly. Change-Id: Ie0b82dca23b7a750658ccc1a85f9daae5fbc20e1 Signed-off-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/170666 Reviewed-by: Kees Cook <keescook@chromium.org> (cherry picked from commit ecec80e062f7efe32a9a17479dcf8cb678a4a98b) Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com> Reviewed-on: http://review.coreboot.org/6780 Tested-by: build bot (Jenkins)
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