You are looking at the source tree for FreeCalypso Citrine, which is one of the
several Calypso GSM firmware offerings developed under the FreeCalypso umbrella.
The key distinguishing features of FC Citrine are:

* The firmware is built from full source, no blobs;
* The compiler used to build the fw is gcc (free software) instead of TI's
  proprietary compiler;
* The way in which the firmware is put together is "from the bottom up".

Our Citrine firmware can be built for the following targets:

  Mot C11x/12x
  Mot C139/140
  Mot C155/156
  Openmoko GTA01/02
  Pirelli DP-L10

However, only minimal functionality is implemented so far: whichever target
device you are using, it can only function as an AT-command-controlled voice+SMS
pseudo-modem; because there is no UI code integrated yet, the LCD stays dark
and the buttons do nothing on those target devices that have such hardware.
No CSD, fax or GPRS support has been integrated yet either, and in general this
Citrine firmware has not yet reached the level of functionality and stability
offered by its blob-laden, Windows-built competitors.  It is a work in progress.

Please refer to the write-ups in the doc directory for instructions on how to
compile and play with this firmware.