--- a/doc/Freerunner-Howto	Sat Mar 05 05:10:49 2016 +0000
+++ b/doc/Freerunner-Howto	Sat Mar 05 20:50:37 2016 +0000
@@ -1,14 +1,45 @@
 How to play with FreeCalypso GSM firmware on a Neo Freerunner
 =============================================================
 
-Aside from the half-source leo2moko fw we produced back in 2013-10 (you can
-read all about that one at www.freecalypso.org/leo2moko/), we don't have a
-working free GSM firmware version for the Freerunner yet.  What we do have
-currently is experimental code that can be built into an image that can be
-flashed into a GTA02 modem - but it doesn't really work yet.
+We have two entirely different firmware offerings for the Freerunner:
+
+1. Leo2moko fw produced back in 2013-10: this is the only one suitable for
+   end users.  We also have leo2moko-debug which is a slightly hacked-up
+   version of leo2moko with some additional debug features for developers;
+   this version is for developers only; end users should stick with the
+   original leo2moko-r1 aka moko12 from 2013-10.
+
+2. The work-in-progress full-source gcc-built FC GSM fw can be built for
+   multiple targets, and the gtamodem target is one of them - the original
+   one, in fact.
 
-If you would like to play with our experimental code on your Neo FR and maybe
-help us make it work, here are the instructions:
+The flash+SRAM chip which FIC/Openmoko populated in their modems provides
+plenty enough RAM for the firmware's data space requirements, but not enough
+to run a complete firmware code image entirely from RAM, hence whichever fw
+version you would like to exercise, you need to flash it.  There are two ways
+to flash modem firmware images in these smartphones: from inside the phone
+(from the application processor) or externally through a special serial cable
+inserted into the analog headset jack.  The internal method is intended only
+for end users flashing released production-quality images; developers and
+tinkerers are expected to use the serial cable method.
+
+The serial cable wiring requirements for the GTA02 are the same as for Mot C1xx
+phones, thus the same cable can be used for both.  The FreeCalypso project has
+endorsed UberWaves as our official vendor for serial cables; George at
+UberWaves now makes serial cables that are specifically certified for use with
+FreeCalypso.  If you would like to order one, email uberwaves@gmail.com.
+
+Please see the Firmware_Status write-up for the current status of our full-
+source gcc-built firmware.  As you can read there, this fw is currently nowhere
+near being able to replace leo2moko.  Therefore, if you are going to flash our
+gcc-built gsm-fw into your FR's modem, we expect that you are using your FR as
+a poor man's substitute for the not-yet-built FCDEV3B (a board we seek to build
+specifically for developers and not for end users), and are NOT expecting this
+experimental work-in-progress modem fw to work together with user-oriented
+application processor software like QtMoko.
+
+If you would like to play with our experimental gcc-built gsm-fw using a GTA02
+modem as the hw platform, here are the instructions:
 
 1. Build the firmware in the gtamodem-gsm configuration - see the Compiling
    document for more details;
@@ -38,11 +69,41 @@
 the modem and see the new fw boot.  You should have the serial cable connected,
 the serial channel enabled from the Freerunner's AP side and either rvtdump or
 rvinterf running on your PC or other development machine when you first power
-your modem up with the experimental fw in it: this way you will see whether the
-fw boots successfully or crashes.  If it does boot without crashing (whether or
-not it does seems to depend on some factors which we have yet to understand),
-you will get an AT command interface on the other UART going to the Freerunner's
-AP - now go ahead and play from there. :)
+your modem up with the experimental fw in it: this way you will see the debug
+output as the firmware boots up.
+
+Once the firmware has booted, it needs to be controlled via AT commands.  The
+present fw presents its AT command interface on two channels on this target: on
+the MODEM UART going to the Freerunner's application processor and via RVTMUX.
+At the present stage of development, we highly recommend that you avoid running
+any GSM-driving software on the AP and exercise our work-in-progress fw solely
+through the external serial interface on the headset jack, using rvinterf and
+fc-shell.  The standard AT command interface on the dedicated MODEM UART is a
+feature which we plan to address properly only when we build our planned FCDEV3B
+hardware, which will bring both UARTs out to the external host.
+
+Assuming that you already have rvinterf running in a terminal window (you should
+have started it before you gave the modem power-on command from the AP side),
+to exercise our firmware further, you will need to open another terminal window
+on your driving PC/laptop and run fc-shell.  This program will connect to the
+already running rvinterf process via a local socket, and it will enable you to
+send various commands to the running fw on the target, the most important ones
+being standard AT commands.  Send the following sequence of AT commands to
+bring up GSM functionality:
+
+AT%SLEEP=2	-- disable deep sleep (doesn't work yet)
+AT+CMEE=2	-- enable verbose error responses
+AT+CFUN=1	-- enable radio and SIM interfaces
+AT+COPS=0	-- register to the default GSM network
+
+Our fw is currently able to exercise all SIM interface functions (at least the
+obvious ones which I've tested), register with a live commercial GSM network
+using a legitimate SIM, and send and receive SMS using standard GSM 07.05 AT
+commands.  Voice calls don't work yet: you can dial a MO call with the ATD
+command and you can place a MT call to the device under test from the network
+side and then answer it with ATA, these calls connect successfully, but the
+voice audio fails to pass through: nothing but noise is heard in the earpiece
+speaker.  See the Firmware_Status write-up for more information.
 
 To reflash your modem back to stable and working leo2moko aka moko12, execute
 the following fc-loadtool commands: