Re: [Qemu-devel] Writing a CAN driver for QEMU

[Paolo Bonzini]

Il 18/05/2013 20:24, Rempel, Cynthia ha scritto:
> we want to be able to verify a guest OS's CAN driver has been integrated 
> properly and is sending CAN packets... 
> 
> Perhaps along the lines of two calls:
> qemu-system-arm -hda linux1.img -can student-implemented-device
> qemu-system-arm -hda linux2.img -can student-implemented-device

You would probably use either -net, or -netdev and -device (see
docs/qdev-device-use.txt).

> Then using a network protocol analyzer (such as Wireshark) with a custom 
> filter to recognize CAN packets,
> OR
> qemu-system-arm -hda linux1.img -can student-implemented-device
> then attaching a real CAN device to the host computer and verifying that the 
> output is being recognized be real hardware.

Is this CAN device just an Ethernet device?  QEMU does not support other
link-level protocols.  Adding them would be possible and interesting,
however it would add a bit to the complexity.

> Whichever is more feasible to implement...

Both would be the same.  In the first case, you'd probably use "-netdev
socket" to share a virtual network between two virtual machines.  In the
second, you would use something like "-netdev tap" (again assuming it's
just an Ethernet device).

Paolo