Thsi is very handy when doing your own kernel development.
-m specifies how much ram (in the example it is 768MB)
-kernel specifies the path to the kernel file
-net tap,ifname=tap1,script=no (the ifname=tap1 is what you need to change and setup manually).
*Run "tunctl -b" to create a tap device and use the one it gives you for ifname=
Enable networking to the outside like this:
*Note we assume that your bridge is br0 i........