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Mychaela Falconia mychaela.falconia at gmail.comVadim Yanitskiy <axilirator at gmail.com> wrote: > So, I think, Motorola C1XX phones remain the primary hardware > back-end for now, thus would be better to tell people about them. Except that Mot C1xx phones with 900+1800 MHz bands are no longer available except occasional single units here and there, so I assume that you meant to say that Calypso devices (Calypso in general rather than Mot C1xx specifically) remain the primary hw back-end, and that it is a good idea to tell people about the availability of new Calypso devices that aren't Mot C1xx phones. As a side-by-side comparison between Mot C1xx phones vs. the newly made FreeCalypso FCDEV3B hardware for the purposes of running OsmocomBB, the differences are: * You need to run a different version of OsmocomBB's layer1: instead of running the version built in board/compal_*/layer1.*, you need to run the board/gta0x/layer1.highram.bin version. * Running the gta0x version of layer1 on the FCDEV3B is technically cheating, as the FCDEV3B is not Openmoko GTA0x - it is very very close, but not identical. * If you are going to exercise voice call functionality and would like to hear the call downlink audio come out of the loudspeaker connected to the FCDEV3B (you'll need to procure the actual loudspeaker part yourself) in the same way how it comes out of the earpiece speaker on Mot C1xx phones, you will need to make a tiny change to the code in board/gta0x/init.c to configure Calypso GPIO 1 as an output and to drive this output high. If the OsmocomBB community wishes to support the FCDEV3B as a hardware target, someone in the OsmocomBB camp (i.e., not me) will need to decide whether to use the same gta0x target for both actual Openmoko GTA0x devices and for the FCDEV3B, or to bifurcate the two. The concerns with using the same gta0x target for both GTA0x and FCDEV3B devices are: * Calypso GPIO 1 should be configured as an output on both targets (the current OsmocomBB code incorrectly leaves it as an input), but it performs different functions on the two hw platforms. On my FCDEV3B it controls the loudspeaker amplifier like on TI's own D-Sample and Leonardo development boards and needs to be driven high to enable it, but on Openmoko devices it is an interrupt to the application processor of the phone. I don't know if anyone cares about running OsmocomBB on OM devices, and what will happen if the code is changed to assert GPIO 1 high. * If you guys ever get around to making use of the factory-written per-unit RF calibration values on the devices you run on, you will need to know whether you are running on GTA0x or FCDEV3B hardware: while the FFS (flash file system) format is exactly the same, the physical flash location of this FFS is different. This factory RF calibration is another big issue in itself. In producing my own FreeCalypso hardware I have expended a very significant effort to produce per-unit RF calibration that is no worse than that which was done by the historical Calypso device manufs like Openmoko, Pirelli and Motorola. Every FCDEV3B board which I offer for sale has passed a calibration procedure in which the DUT was connected to a Rohde&Schwarz CMU200 Universal Radio Communication Tester (the exact same professional RF test equipment that was used by all of the big guys in the days of yore), and the following RF parameters are precisely calibrated for each individual unit: * The VCXO frequency as a function of the AFC DAC control value, for use by the advanced AFC algorithm implemented by TI for use in production firmwares; * The correct APC DAC values to produce each of the Tx power levels specified in the GSM 05.05 spec for all 3 supported bands, putting each Tx power level exactly where it needs to be per spec, within the tolerances given in the spec; * The "magic gain" constant needed in order to determine the actual input level in dBm from the DSP's power measurement, for each of the 3 supported bands; * The per-channel variation in this "magic gain" constant caused by the irregularities in the passband of the SAW filters, needed for proper RSSI reporting. Thanks to this proper RF calibration, I have a very high confidence that the radio operation of my FreeCalypso devices when running the official FreeCalypso Magnetite firmware is 100% correct per all of the relevant official specs, and that my hw+fw combo would pass FCC/etc certification and type approval testing if someone were to cough up the $$$ for it. All other Calypso devices that are currently supported by OsmocomBB (Mot C1xx, Pirelli DP-L10, Openmoko GTA0x) also had the same kind of per-unit RF calibration performed at their respective factories, with the results saved either in the FFS in TI's format (in the case of OM GTA0x) or in some proprietary flash data structure (in the case of Mot C1xx and Pirelli DP-L10), but OsmocomBB fails to make use of these data on any target, even on those on which the location and format of these factory RF calibration values are well-known. I naturally have my reservations about expending the effort to calibrate each hardware unit I produce with utmost diligence, only to sell them to people who are going to run firmware that completely ignores these factory RF calibration values and runs with some hard-coded off-the-wall numbers instead. M~