New Life in Openmoko Phones

Werner Almesberger werner at openmoko.org
Fri May 22 03:37:19 CEST 2009


Nils Faerber wrote:
> Wouldn't it be more fruitful to create a project that is only concerned
> about providing the best possible tools, hardware and software, for
> braking into and reverse engineering existing devices?

There are already a number of projects that do exactly this, such
as OpenEZX and gnufiish. There are a number of limitations to this
approach, though:

- there's always the risk that you can't "forcibly open" some
  important chips

  E.g. see the still large number of "0%" items on
  http://gnufiish.org/trac/wiki/Project_Status

- it's difficuly to get power management right without knowing
  exactly what goes on in the device

- even if you succeed, there's no guarantee that the vendor won't
  make some changes for the worse (from the Open Source point of
  view) in new revisions of the product.

  E.g., OpenWRT got bitten by a radical change of the core system
  architecture of the WRT54G. Luckily, LinkSys/Cisco could be
  convinced to make a variant specifically targetted for Linux.

- worse yet, considering the amount of time such reverse engineering
  takes and the short life cycles of these products, the product may
  already have been replaced by the time you catch up. This means
  that it will be very difficult to spread such opened devices
  outside a groups of very determined enthusiasts.

  E.g., consider the age of the hardware OpenEZX, being in fairly
  good shape as far as the software is concerned, uses.

Of course, none of this means that this approach is guaranteed to
fail, there is the success story of the WRT54G, but that's also
a much simpler and extremely long-lived device.

So the bottom line is that I don't think this approach can only
scale if you can convince the company whose phone you "opened" to
cooperate with you. And it's unlikely that they would be able to
open their design, even if you could convince them they should.

On the other hand, the approach where you own the design can be
brought to mass-production with anyone's support. Even a small
carrier or a consortium of interested parties could do it.

Furthermore, an open design lowers the barrier of entry for people
who want to make variants. Not only do they not have to license
the design, but they also don't depend on a single company to
support them.

> Hardware is needed in the form of good debug adapters. Those would be
> much easier to have made than a complete phone device. Good software is
> needed for the hardware debuggers and also for disassembly analysis,
> protocol analysis etc.

I think in terms of tools, both approaches can share a lot. A
protocol analyzer will help you debug your own implementation 
just as well as it will help you to discover a vendor's mystery
protocol.

- Werner




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