[ltp] Re: Intel 2100b WiFi Card

[Tod Harter]

> > Second, those are exactly the people smart enough to pick up the
> > Windows driver, disassemble it and find out what they want to know
> > anyway.
>
> Nope, that only gets them so far. It doesn't matter if they take apart
> the Windows driver or the closed-source binary Linux driver, all they
> see is that the driver pokes mysterious values into the hardware.
> Getting to the meaning of those values is not as easy as looking at the
> driver disassembly.
>
I don't agree. I wrote a lot of device drivers back in the old days. You give 
me a piece of paper that says 'when the driver wants to output at frequence X 
it sets register A to value Y' and a few examples of that and I guarantee it 
won't take but a couple hours to figure it out.

Basically whatever the value is thats input is going to be somehow scaled to a 
frequency. Most likely its a direct input to a clock divider. If you know 
what clock chip they're using then you probably have the documentation you 
need in the clear.

Worst case scenario is that they've totally scrambled the bits along the way, 
xored them with something, etc. In that case its STILL just a matter of 
trial-and-error, pretty soon your going to learn that bit 1 of register A 
doubles the frequency, and bit 6 increments it by some other factor, etc. Or 
at least you'll find which bit patterns result in output on certain 
frequencies.

Granted you might need SOME test equipment, but I know plenty of guys that 
have good enough 'scopes in their garages to get the job done. Just an 
afternoon's worth of puzzle-solving is all it is ;o).

-- 
Giant Electronic Brain
Internet/E-Commerce Consulting Services