TABLE OF CONTENTS Unless you've been privy to some previous 802.11b and PRISM experience, right now the words FID, RID and BAP most likely mean very little to you. However, those little three- letter acronyms are all over any 802.11b driver source code you're ever likely to see. The PRISM acronyms are also carefully placed in PRISM chipset data sheets as well. Fortunately, careful observation of the available PRISM chipset data sheets gives us an insight as to what those acronyms mean and what they are to the AirDrop driver modules and 802.11b. With that, let's do some PRISM chipset spelunking.
If you've scanned the massive amount of Linux 802.11b source on the Internet, you've probably seen references to downloading code to PRISM chipsets. We won't be doing any of that. However, just the notion of being able to push bytes into an 802.11b NIC implies that firmware controls the beast. In fact, I came across a couple of internet documents that detailed the downloading of code to a PRISM-equipped NIC. The concrete was set when I read the second paragraph of the ISL3873A data sheet. It stated that firmware implements the full IEEE 802.11 wireless LAN MAC protocol. That one sentence containing the words "firmware implements" is our 802.11b emanci-pation proclamation.
Figure 7.1 is a graphical depiction of the MAC area of the ISL3873A. Lots of things we'll talk about later when we start a detailed examination of the AirDrop driver source code are performed...
