You are looking at the top level of the freecalypso-sw source code tree.
The subtrees of this source tree are as follows:

gsm-fw		This tree contains the early beginnings of my (Michael
		Spacefalcon's) attempt to recreate TI's GSM firmware suite for
		modems and basic phones, consisting of Nucleus RTOS, RiViera
		and GPF frameworks, TI's BSP/driver and L1 code, Condat G23
		GSM/GPRS protocol stack, AT command interpreter and UI layers.

		At the present, none of the actual GSM code (L1 or G23) has
		been integrated yet, but most of the underlying RTOS environment
		is present and working: one can exercise RVT, ETM and FFS.
		L1 integration will begin soon.

ffstools	Here you will find tools for "in vitro" examination of FFS
		(flash file system) images read out of TI-based GSM devices.
		See doc/TIFFS-Overview for more information.

loadtools	The suite of tools which run on a development host machine
		(normally PC/Linux desktop or laptop) and communicate with
		Calypso targets.  Starting from the Calypso ROM bootloader,
		these tools allow you to peek and poke registers, read and
		program flash, and load and execute experimental code in IRAM
		or XRAM.

rvinterf	In common with TI's original fw, FreeCalypso GSM fw implements
		the so-called RiViera serial MUX, which is a binary packet
		protocol for multiplexing many kinds of debug and development
		traffic over just one available physical serial port.  This
		rvinterf directory contains the early beginnings of our suite
		of tools for connecting to this RV serial interface, supporting
		both our own gsm-fw as well as some existing proprietary
		firmwares to the extent to which they are compatible.

target-utils	These are utilities which run on Calypso targets, but which are
		independent of Nucleus, of any other RTOS, and of any larger
		firmware suite, i.e., totally standalone.  The two current
		utilities are loadagent, which is common for all currently
		supported Calypso targets and is required in order to use
		fc-loadtool or fc-xram (see loadtools), and pirexplore - the
		latter is a hardware exploration utility specific to the
		Pirelli DP-L10 target.

toolchain	Scripts and patches for building the gcc+binutils toolchain
		targeting ARM7, the CPU core of the Calypso GSM/GPRS baseband
		processor.  You'll need to build and install this toolchain
		first before you can build gsm-fw or target-utils.