Hello again everyone, Thanks to a recent donation of 3 non-sellable Openmoko GTA02 units (supposedly defective, although I haven't really noticed the presumed defects) from Openmoko seller Christoph Pulster, I now have a total of 4 GTA02s including my original one, and I have read Calypso flash dumps from all of them. As a side note, if you are performing low-level operations on the GTA02's Calypso block where you don't need the internal UART or audio channels, you can do these operations from the always-present NOR U-Boot without depending on any higher-level software in the phone's NAND flash: just get into the NOR U-Boot, connect USB, run your favourite terminal program on /dev/ttyACM0 that should appear on your host while the FR is in U-Boot, give it a 'setenv boot_menu_timeout 3600' command to keep it from powering off on its own, and then use the 'neo gsm on' and 'neo gsm off' U-Boot commands to turn the modem on and off. These commands also enable the secondary Calypso serial channel on the headset jack, hence you can use that channel to poke at the modem. Om's factory must have used this method for their initial fw loading and RF calibration, but if you load one of the newer (post-leo2moko) FC fw versions that have the AT-over-RVTMUX extension, you can also issue AT commands this way - just not CSD or GPRS, and there is no way to get to the voice audio channel in this arrangement.
Anyways, so I have used this NOR U-Boot trick to read Calypso flash dumps from the 3 new GTA02s I just acquired, and now we have a total of 6 examples of per-unit RF calibration values: 4 samples from the 4 GTA02 units in my hands, plus the ones which community members David and Giacomo sent me back in 2014. The RF calibration values are stored in the modem's flash file system in binary form, but I recently wrote a utility that converts them from binary into an ASCII text representation that is both human- and machine-readable; the ASCII-based format emitted by this converter is the same as that which I implemented in fc-tmsh for sending RF tables to or reading such tables from live firmwares in Test Mode operation with rftw, rftr, ttw and ttr commands. I have just put out a tarball containing all 6 GTA02 RF calibration samples plus the firmware's compiled-in defaults in the readable ASCII text form: ftp://ftp.freecalypso.org/pub/GSM/GTA02/rfcal-examples.tar.gz If you are curious about per-unit RF calibration on Calypso phones and modems, i.e., curious as to exactly what varies from one unit to the next and the magnitude of these differences, I encourage you to download the above tarball and look inside - it's all readable ASCII text files (mostly tables of numbers) inside, no binary files. I am still waiting for that CMU200 from ebay before we can do our own RF calibration - at this point it is uncertain what will arrive first, this CMU200 or our own FCDEV3B boards. If I receive the CMU200 before we have the FCDEV3B, I'll try connecting the CMU200 to the RF test port on the Openmoko-made GTA02s I have (accessible with the back cover off, just like the battery and the SIM and uSD slots), and see if I can recreate any of the factory calibration steps. Hasta la Victoria, Siempre! _______________________________________________ Community mailing list Community@freecalypso.org https://www.freecalypso.org/mailman/listinfo/community