Archipelago » qemu

@item

PCI UHCI USB controller and a virtual USB hub.

USB options:

@table @option

@item -usb

Enable the USB driver (will be the default soon)

@item -usbdevice devname

Add the USB device @var{devname}. See the monitor command

@code{usb_add} to have more information.

@end table

@item info pci

show emulated PCI device

@item info usb

show USB devices plugged on the virtual USB hub

@item info usbhost

show all USB host devices

@item usb_add devname

Plug the USB device devname to the QEMU virtual USB hub. @var{devname}

is either a virtual device name (for example @code{mouse}) or a host

USB device identifier. Host USB device identifiers have the following

syntax: @code{host:bus.addr} or @code{host:vendor_id:product_id}.

@item usb_del devname

Remove the USB device @var{devname} from the QEMU virtual USB

hub. @var{devname} has the syntax @code{bus.addr}. Use the monitor

command @code{info usb} to see the devices you can remove.

@section USB emulation

QEMU emulates a PCI UHCI USB controller and a 8 port USB hub connected

to it. You can virtually plug to the hub virtual USB devices or real

host USB devices (experimental, works only on Linux hosts).

@subsection Using virtual USB devices

A virtual USB mouse device is available for testing in QEMU.

You can try it with the following monitor commands:

@example

# add the mouse device

(qemu) usb_add mouse 

# show the virtual USB devices plugged on the QEMU Virtual USB hub

(qemu) info usb

  Device 0.3, speed 12 Mb/s

# after some time you can try to remove the mouse

(qemu) usb_del 0.3

@end example

The option @option{-usbdevice} is similar to the monitor command

@code{usb_add}.

@subsection Using host USB devices on a Linux host

WARNING: this is an experimental feature. QEMU will slow down when

using it. USB devices requiring real time streaming (i.e. USB Video

Cameras) are not supported yet.

@enumerate

@item If you use an early Linux 2.4 kernel, verify that no Linux driver 

is actually using the USB device. A simple way to do that is simply to

disable the corresponding kernel module by renaming it from @file{mydriver.o}

to @file{mydriver.o.disabled}.

@item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:

@example

ls /proc/bus/usb

001  devices  drivers

@end example

@item Since only root can access to the USB devices directly, you can either launch QEMU as root or change the permissions of the USB devices you want to use. For testing, the following suffices:

@example

chown -R myuid /proc/bus/usb

@end example

@item Launch QEMU and do in the monitor:

@example 

info usbhost

  Device 1.2, speed 480 Mb/s

    Class 00: USB device 1234:5678, USB DISK

@end example

You should see the list of the devices you can use (Never try to use

hubs, it won't work).

@item Add the device in QEMU by using:

@example 

usb_add host:1234:5678

@end example

Normally the guest OS should report that a new USB device is

plugged. You can use the option @option{-usbdevice} to do the same.

@item Now you can try to use the host USB device in QEMU.

@end enumerate

When relaunching QEMU, you may have to unplug and plug again the USB

device to make it work again (this is a bug).

           "-usb            enable the USB driver (will be the default soon)\n"

           "-usbdevice name add the host or guest USB device 'name'\n"