Scared of hard work ?

Posted Oct 14, 2010 8:11 UTC (Thu) by amimjf (guest, #506)
In reply to: Scared of hard work ? by bronson
Parent article: HTC Willfully Violates the GPL in T-Mobile's New G2 Android Phone (Freedom to Tinker)

I've seen data sheets lacking detail on a couple of occasions in the last decade, so you just have to work it out for yourself. Data sheets are almost always very good in my experience.

I've never seen the inside of the phone they are reverse engineering, but unless there are FPGA's or ASIC's hiding certain parts of behavior you just have to trace out the lines from one component to another.

Take the example of a first prototype back from manufacture, it does not work at all, so what do you do ? you get your scope and follow the lines from one chip to another until you know where the fault is.

Anyhow this is all moot, the engineers at HTC have done all this once so anybody else with a similar level of skill can. All this episode shows is that the HTC guys are pretty good.

Scared of hard work ?

Posted Oct 14, 2010 17:40 UTC (Thu) by bronson (subscriber, #4806) [Link]

Everything looks easy when someone else is doing it.

Have you actually seen a modern cell phone PCB? It's all BGAs or worse. 80% of the traces are buried so they can't be probed without delaming, and even those on the surface are so small that you need specialized probes just to hit reliably. "Just scope it" isn't really an option anymore.

> HTC have done all this once so anybody else with a similar level of skill can.

And a similar access to SanDisk engineering support.

Scared of hard work ?

Posted Oct 18, 2010 0:38 UTC (Mon) by dmag (guest, #17775) [Link]

> Data sheets are almost always very good in my experience.

You haven't worked on enough ARM chips recently. These companies get a well documented ARM core, throw some custom peripherals on it and forget to document all the possible interactions. (Sharp, I'm looking at you.) I won't even mention the engrish in the datasheet, since I expect that nowadays.

> but unless there are FPGA's or ASIC's hiding certain parts of behavior

Today's modern ARM chips have so many functions per pin (always at least two, sometimes four) that the configuration code might be more valuable than a circuit diagram. even without an FPGA

> the engineers at HTC have done all this once so anybody else with a similar level of skill can

It sounds like you are saying "engineering and reverse engineering are the same effort." That's not even close to true.