Once upon a time, in a distant era long gone by, TI used to make cellular baseband chipsets for GSM/2G and UMTS/3G. These chips have been out of production for many years, but I can still buy at least tens of thousands and likely even hundreds of thousands of pieces of these old TI-made chips on the Chinese surplus market. I understand that TI cannot make any guarantees about the quality and integrity of these parts because they have been handled in an unknown manner, but I do my own extensive testing, and they work great. I also understand that TI does not provide any support for these obsolete products, but I have been doing a pretty damn good job so far at self-supporting my project using materials scavenged on the Internet.
The name of my project is FreeCalypso, www.freecalypso.org is the project website. My project has been a huge success so far: I have designed and built my own development board for TI's Calypso+Iota+Rita GSM chipset, a board which I named FCDEV3B; out of TI's own historical development boards for these chips (D-Sample, E-Sample, Leonardo) my FCDEV3B is closest to Leonardo. These boards of my own design and make, built with old TI-made chips from the Chinese surplus market, work wonders - I have my own R&S CMU200 GSM RF test instrument, I use it to test and calibrate the RF tract on my indie TI-based GSM devices, and I have verified with this test instrument that all GSM radio transmissions put out by my FCDEV3B modems are 100% spec-compliant, which is very important when working in the tightly regulated GSM frequency bands. I now have a fully functional, commercial quality GSM+GPRS modem with the special distinction that I am fully empowered to study and understand all of its inner workings! The worldwide Free Software community has been complaining for over a decade now about there not being any cellular modems whose insides are open to study and understanding - well, my project is a big break from that bleak status quo!
The biggest challenge for my project, however, has been with the software or firmware that is needed in order to make these GSM baseband chips do their useful function, i.e., GSM Layer 1 and protocol stack firmware. Back when TI actively made, sold and supported these chips (a full decade ago), TI also developed and maintained the necessary firmware. However, with TI no longer providing any support for this discontinued product line, I have not been able to obtain any official firmware delivery directly from TI, hence I had to resort to alternative means.
As I understand it, TI's software or firmware suite for the Calypso+Iota+Rita chipset was called TCS2.1.1 or TCS211 for short. In 2013 I found the remains of an out-of-business GSM device manufacturer (i.e., an out-of-business company that previously made GSM modems with TI's Calypso chipset), and I convinced them to sell me their old product design: their board schematics and PCB layout files, as well as the TCS211 firmware delivery they got from TI. Thus I now have what may be the world's last surviving copy of TI's TCS211 firmware for the Calypso+Iota+Rita GSM chipset.
However, this TCS211 delivery I got from that out-of-business company (Sotovik) was only about half C source, with the other half being linkable binary objects. Back in the days when TI provided support, if there was a problem in the firmware components for which no source code was provided, the customer would ask TI for help, TI would maintain that code and make new releases with bugfixes - but now that TI support is no more, I need to be 100% self-supporting (or to put it another way, I rather than TI am now the custodian and sole provider of support for this software), thus I needed 100% C source code, no binary object blobs. Thus I set out to deblob what I believe to be the world's last surviving copy of TCS211, a job which I successfully completed by around 2017.
I have used my advanced reverse engineering skills and tools to disassemble the binary object blobs and to reconstruct the missing parts of the source, and for one major component of the firmware suite (the G23M protocol stack, which is mostly chipset-independent) I was able to replace the TCS211 binary objects version with a different version that came in full C source form - I took that other version from the TCS3.2_N5.24_M18_V1.11_M23BTH_PSL1_src.zip firmware for LoCosto (another TI GSM chip) which was published freely on the Internet by Peek Inc. (a LoCosto-based device manufacturer) in 2012 as that company went under.
I do wonder, however, whether or not there is anyone else in the world (either at TI or some outside engineer who previously worked with these TI products) who fondly remembers the days I am talking about and who might be open to extending me some friendship, or maybe even helping me find more surviving bits of material. In addition to my own FCDEV3B boards, I also have an original TI-made D-Sample board, and I would love to get this board working, but I am missing two key pieces for that board: (1) I have no schematics for this D-Sample, and without schematics I am not able to figure out how to exercise the battery charging circuit on this board and how the LCD interface works, and (2) I am missing the tpudrv10.c module, without which I am not able to bring up the GSM radio on the D-Sample, i.e., the main function.
In the case of the TPU driver, the half-source, half-binary delivery of TCS211 I got came with L1 in binary object form; through years of painstaking work I have now reconstructed almost all of the missing L1 source, but because this specific half-source, half-binary delivery was made for a customer that used Rita RF, it only has the tpudrv12 driver for Rita RF, no tpudrv10 for Clara RF. And even the Rita RF driver came as tpudrv12.obj instead of tpudrv12.c; I have disassembled that object and produced my own tpudrv12.c reconstructed source that compiles into a functional equivalent to the delivered object blob, but if someone out there has a surviving copy of the original tpudrv12.c source module, I would be absolutely delighted.
So, is there anyone anywhere in the world (at TI or elsewhere) who has another surviving copy of TI's TCS211 firmware for the Calypso baseband, a copy that includes tpudrv10.c and tpudrv12.c modules?
