Hi Martin, On Sat, Nov 26, 2011 at 02:03:50AM +0100, Martin Hinner wrote: the question really is how many of them you need. Economically, the question is: * what is the price of the required qty of calypso based phones vs * what is the amount of work needed for porting to MTK Even under the most ideal circumstances, porting the L1 to any new baseband chip architecture is going to be a lot of work. As "ideal circumstances" I count * detailed knowledge about not only the integrated peripherals of the DBB but also register-level documentation of the ABB * detailed knowledge about the shared memory API between DSP-ROM and ARM CPU * no cryptographic verification in bootloader that needs to be broken * a developer who has very strong background on GSM L1 and cellphone hardware * access to measurement devices for MS testing like Racal 6103 Even under such circumstances, I would guess an effort of somewhere between 1 to 2 man-months full-time. As the circumstances are never ideal, it will likely be more effort. Some developers have already put quite a bit of effort into the MTK chipset side, and even though we don't have the register-level data sheets of all of the ABB chips and the DBB data sheets do not cover anything on the details of the DSP/ARM API interface, I think it is the most promising architecture. I think the big issue is availability. The people invovled in OsmocomBB are working on a variety of other projects and protocol stacks (OsmocomGMR, OsmocomTETRA, osmo-bts, etc.) So the big question is: How can you convince anyone from the existing team to contribute to a port to MTK? I think the fact that the code runs well on the Calypso based phones (which are still avialable even in quantity) makes this a bit difficult, as there is no real gain. People generally want to work on creating new functionality, rather than re-creating something that already exists... On the other hand: C166 is a one-way road. No new baseband chipsets (even infineon) use them anymore. You need to port all the arm-specific assembly bits in OsmocomBB to the C166 code, etc. MTK is a much more attractive target. More docs, more understanding, more existing code and ARM based. Regards, Harald -- - Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)