qemu-patch-raspberry4/docs/usb2.txt
Gerd Hoffmann 94527ead7e usb: add ehci adapter
This patch finally merges the EHCI host adapter aka USB 2.0 support.

Based on the ehci bits collected @ git://git.kiszka.org/qemu.git ehci

EHCI has a long out-of-tree history.  Project was started by Mark
Burkley, with contributions by Niels de Vos.  David S. Ahern continued
working on it.  Kevin Wolf, Jan Kiszka and Vincent Palatin contributed
bugfixes.

/me (Gerd Hoffmann) picked it up where it left off, prepared the code
for merge, fixed a few bugs and added basic user docs.

Cc: David S. Ahern <daahern@cisco.com>
Cc: Jan Kiszka <jan.kiszka@web.de>
Cc: Kevin Wolf <mail@kevin-wolf.de>
Cc: Vincent Palatin <vincent.palatin_qemu@m4x.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2011-05-26 11:57:09 +02:00

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USB 2.0 Quick Start
===================
The QEMU EHCI Adapter does *not* support companion controllers. That
implies there are two completely separate USB busses: One USB 1.1 bus
driven by the UHCI controller and one USB 2.0 bus driven by the EHCI
controller. Devices must be attached to the correct controller
manually.
The '-usb' switch will make qemu create the UHCI controller as part of
the PIIX3 chipset. The USB 1.1 bus will carry the name "usb.0".
You can use the standard -device switch to add a EHCI controller to
your virtual machine. It is strongly recommended to specify an ID for
the controller so the USB 2.0 bus gets a individual name, for example
'-device usb-ehci,id=ehci". This will give you a USB 2.0 bus named
"ehci.0".
I strongly recomment to also use -device to attach usb devices because
you can specify the bus they should be attached to this way. Here is
a complete example:
qemu -M pc ${otheroptions} \
-drive if=none,id=usbstick,file=/path/to/image \
-usb \
-device usb-ehci,id=ehci \
-device usb-tablet,bus=usb.0 \
-device usb-storage,bus=ehci.0,drive=usbstick
This attaches a usb tablet to the UHCI adapter and a usb mass storage
device to the EHCI adapter.
enjoy,
Gerd
--
Gerd Hoffmann <kraxel@redhat.com>