The awi driver supports various IEEE 802.11 wireless cards which run AMD PCnetMobile firmware based on AMD 79c930 controller with Intersil (formerly Harris) PRISM radio chipset. It provides access to 32kb of memory shared between the controller and the host. All host/device interaction is via this shared memory, which can be accessed either via PCMCIA memory space or I/O space. The awi driver encapsulates all IP and ARP traffic as 802.11 frames.
The driver works both in infrastructure mode and in adhoc (independent BSS) mode.
In infrastructure mode, it communicates with an Access Point which serves as a link-layer bridge between an Ethernet and the wireless network. An access point also provides roaming capability which allows wireless nodes to move between access points.
In adhoc mode, it communicates peer to peer. Though it is more efficient to communicate between wireless nodes, the coverage is limited spatially due to lack of roaming capability.
In addition to these two modes in the IEEE 802.11 specification, the awi driver also supports a variant of adhoc mode out of spec for DS radio cards, which makes it possible to communicate with adhoc mode of wi(4) driver. The NWID does not affect in this mode.
For more information on configuring this device, see ifconfig(8).
Cards supported by the awi driver include: