You are looking at the suite of FreeCalypso tools for talking to the RVTMUX
interface provided by TI-based GSM firmwares.  If you haven't already, please
read ../doc/RVTMUX first.

The fundamental difference between these tools and loadtools is that loadtools
operate on a GSM device while its regular firmware is shut down, whereas the
present rvinterf tools talk to active running GSM firmwares.

The following tools are currently implemented:

rvtdump		Opens the serial port, decodes TI's binary packet protocol, and
		simply dumps every received/decoded packet on stdout in a human-
		readable form.  No provision for sending anything to the target.
		Intended use: observing the debug trace output which all TI
		firmwares emit as standard "background noise".  This utility
		allows one to observe/log/study the "noise" that appears on
		Pirelli's USB-serial port (running Pirelli's original fw),
		as well as that emitted on the IrDA (headset jack) port on the
		GTA02 by mokoN/leo2moko firmwares.

rvinterf	Provides a bidirectional interface to RVTMUX on the host side.
		It dumps and/or logs the "background noise" emitted by the
		target just like rvtdump, but also creates a local UNIX domain
		socket on the host machine to which other programs can connect,
		replicating the MUXing function on the host side.

fc-tmsh		Interactive asynchronous test mode shell.  This program connects
		to a target GSM device through rvinterf and allows a developer-
		operator to send various ETM commands to the target.  ETM
		responses are decoded (sometimes only lightly) and displayed.
		fc-tmsh is fully asynchronous in that it continuously listens
		(via select(2)) both for user input and for packets from the
		target at the same time, translating any user-entered commands
		into packets to the target and conversely, scribbling on the
		terminal when a packet arrives from the target.  It has no
		knowledge of any correspondence between commands and responses
		they normally elicit.

g23sh		Like fc-tmsh (same asynchronous design), but for GPF/G23 rather
		than ETM.  This tool and FreeCalypso project's understanding of
		GPF/G23 in general are currently in the earliest stages, so it
		is premature to try to describe it any further at this point.

fc-sendsp	Precursor to g23sh; even less worthy of further documentation.

fc-fsio		This program uses RVTMUX, ETM and TMFFS2 to access the live file
		system of a running GSM firmware.  Of the existing proprietary
		firmwares, the only one that implements the TMFFS2 protocol
		required for fc-fsio is Pirelli's, to the best of our knowledge.
		This program connects to the target through rvinterf, but it
		differs from fc-tmsh in that it operates in a synchronous
		manner: the flow of operation is driven by user commands (just
		like in fc-loadtool), and every time the program sends an ETM
		command packet to the target, it expects a lock-step response.

tfc139		See ../doc/Compal-unlock

The fc-fsio, fc-tmsh and g23sh tools connect to the target not directly, but
via rvinterf.  Two usage scenarios are supported:

1. The user explicitly runs rvinterf (either directly or secondary to fc-xram,
   when testing an experimental FreeCalypso firmware ramImage), leaves it
   running (either backgrounded or in its own terminal window), and then runs
   one of the "client" programs: fc-fsio, fc-tmsh or g23sh.  The two programs
   connect via local UNIX domain sockets on the host machine.

2. All of the "client" programs under discussion can also launch rvinterf
   themselves.  An instance of rvinterf lauched in this manner becomes a child
   process of the "client" program, terminating together with it, and the two
   processes communicate via an unnamed and unbound socket pair.