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−How to play with FreeCalypso GSM firmware on a Neo Freerunner
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−=============================================================
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−
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−We have two entirely different firmware offerings for the Freerunner:
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−
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−1. Leo2moko fw produced back in 2013-10: this is the only one suitable for
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−   end users.  We also have leo2moko-debug which is a slightly hacked-up
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−   version of leo2moko with some additional debug features for developers;
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−   this version is for developers only; end users should stick with the
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−   original leo2moko-r1 aka moko12 from 2013-10.
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−
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−2. The work-in-progress full-source gcc-built FC GSM fw can be built for
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−   multiple targets, and the gtamodem target is one of them - the original
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−   one, in fact.
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−
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−The flash+SRAM chip which FIC/Openmoko populated in their modems provides
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−plenty enough RAM for the firmware's data space requirements, but not enough
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−to run a complete firmware code image entirely from RAM, hence whichever fw
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−version you would like to exercise, you need to flash it.  There are two ways
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−to flash modem firmware images in these smartphones: from inside the phone
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−(from the application processor) or externally through a special serial cable
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−inserted into the analog headset jack.  The internal method is intended only
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−for end users flashing released production-quality images; developers and
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−tinkerers are expected to use the serial cable method.
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−
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−The serial cable wiring requirements for the GTA02 are the same as for Mot C1xx
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−phones, thus the same cable can be used for both.  The FreeCalypso project has
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−endorsed UberWaves as our official vendor for serial cables; George at
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−UberWaves now makes serial cables that are specifically certified for use with
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−FreeCalypso.  If you would like to order one, email uberwaves@gmail.com.
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−
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−Please see the Firmware_Status write-up for the current status of our full-
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−source gcc-built firmware.  As you can read there, this fw is currently nowhere
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−near being able to replace leo2moko.  Therefore, if you are going to flash our
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−gcc-built gsm-fw into your FR's modem, we expect that you are using your FR as
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−a poor man's substitute for the not-yet-built FCDEV3B (a board we seek to build
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−specifically for developers and not for end users), and are NOT expecting this
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−experimental work-in-progress modem fw to work together with user-oriented
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−application processor software like QtMoko.
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−
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−If you would like to play with our experimental gcc-built gsm-fw using a GTA02
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−modem as the hw platform, here are the instructions:
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−
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−1. Build the firmware in the gtamodem-gsm configuration - see the Compiling
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−   document for more details;
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−
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−2. You should get a flashImage.bin image built; now you need to flash it into
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−   your FR's modem.  The serial cable method is highly recommended: the only
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−   thing you'll be able to do with our current non-working firmware is help us
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−   debug it, and the serial cable will be needed for the latter part anyway.
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−
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−3. Run fc-loadtool the same way you would if you were flashing leo2moko;
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−
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−4. The actual flash programming commands are a little different because the
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−   image is smaller and in a different format:
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−
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−flash erase 0 0x160000
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−flash program-bin 0 finlink/flashImage.bin
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−
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−The second number in the flash erase command needs to be the size of
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−flashImage.bin rounded up to a multiple of 64 KiB (the flash sector size in the
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−GTA02 modem); 0x160000 is correct for the fw image size as of this writing, but
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−please double-check it yourself before flashing.  The 0 argument in the
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−flash program-bin command is the flash offset at which the image should be
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−programmed: it will always be 0 for FreeCalypso flashable fw images for gtamodem
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−and other targets that have the Calypso boot ROM enabled in the hardware.
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−
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−Once you have flashed our experimental fw into your modem, you can power-cycle
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−the modem and see the new fw boot.  You should have the serial cable connected,
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−the serial channel enabled from the Freerunner's AP side and either rvtdump or
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−rvinterf running on your PC or other development machine when you first power
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−your modem up with the experimental fw in it: this way you will see the debug
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−output as the firmware boots up.
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−
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−Once the firmware has booted, it needs to be controlled via AT commands.  The
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−present fw presents its AT command interface on two channels on this target: on
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−the MODEM UART going to the Freerunner's application processor and via RVTMUX.
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−At the present stage of development, we highly recommend that you avoid running
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−any GSM-driving software on the AP and exercise our work-in-progress fw solely
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−through the external serial interface on the headset jack, using rvinterf and
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−fc-shell.  The standard AT command interface on the dedicated MODEM UART is a
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−feature which we plan to address properly only when we build our planned FCDEV3B
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−hardware, which will bring both UARTs out to the external host.
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−
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−Assuming that you already have rvinterf running in a terminal window (you should
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−have started it before you gave the modem power-on command from the AP side),
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−to exercise our firmware further, you will need to open another terminal window
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−on your driving PC/laptop and run fc-shell.  This program will connect to the
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−already running rvinterf process via a local socket, and it will enable you to
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−send various commands to the running fw on the target, the most important ones
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−being standard AT commands.  Send the following sequence of AT commands to
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−bring up GSM functionality:
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−
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−AT%SLEEP=2	-- disable deep sleep (doesn't work yet)
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−AT+CMEE=2	-- enable verbose error responses
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−AT+CFUN=1	-- enable radio and SIM interfaces
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−AT+COPS=0	-- register to the default GSM network
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−
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−Our fw is currently able to exercise all SIM interface functions (at least the
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−obvious ones which I've tested), register with a live commercial GSM network
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−using a legitimate SIM, and send and receive SMS using standard GSM 07.05 AT
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−commands.  Voice calls don't work yet: you can dial a MO call with the ATD
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−command and you can place a MT call to the device under test from the network
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−side and then answer it with ATA, these calls connect successfully, but the
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−voice audio fails to pass through: nothing but noise is heard in the earpiece
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−speaker.  See the Firmware_Status write-up for more information.
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−
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−To reflash your modem back to stable and working leo2moko aka moko12, execute
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−the following fc-loadtool commands:
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−
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−flash erase 0 0x230000
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−flash program-m0 leo2moko.m0
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−
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−(Whichever firmware image you are flashing, the flash erase command needs to
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− cover the range of flash sectors this image will occupy.  You can erase more
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− sectors up to 0x300000, the "natural" boundary of the flash area where fw
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− images live, but I prefer to erase only the needed number of sectors: it is
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− both faster and imposes less wear on the flash.)