dev An ethernet device structure to be filled in, or NULL if a new
struct should be allocated.
sizeof_privSize of additional driver-private structure to be allocated for this ethernet device
Fill in the fields of the device structure with ethernet-generic values.
If no device structure is passed, a new one is constructed, complete with
a private data area of size sizeof_priv. A 32-byte (not bit)
alignment is enforced for this private data area.
If an empty string area is passed as dev->name, or a new structure is made, a new name string is constructed.