There are a number of UML-specific command-line options. The largest group configures the hardware and devices that the virtual machine will have. The rest are used to specify how the instance will be managed from the host, to set debugging options, or to print information about the UML instance.
The following options set configurations for virtual devices and hardware.
dsp device and mixer= mixer device—These two options specify the host audio interfaces for the use of the UML audio pass-through driver. The default values are
/dev/sound/mixer, respectively. If you wish to play sound from within your UML instance, and the host digital signal processor ...