some links for Nokia N95

Harald Welte laforge at gnumonks.org
Tue Feb 23 20:57:45 UTC 2010


On Tue, Feb 23, 2010 at 08:21:21PM +0100, Benjamin Hagemann wrote:
 
> I have collected some informations / links for Nokia N95 and similar
> topics. Maybe some of them are good enough for the wiki.

> http://www.nokiaport.de/n95info/?id=processor

this is the application processor, not the baseband processor.

All nokia phones that I've ever seen run a nokia-internal/custom baseband
processor (sometimes referred as CMT).  They have generations like DCT3, DCT4,
DCT4+ or today something like BB4, BB5, ...   As those processors are custom
designs that are never sold to other companies, it is unlikely that any
documentation has leaked.

Thus, I doubt you will ever find sufficient information outside Nokia to
understand them sufficiently to run custom software on them.

The wider a particular baseband processor is used (i.e. the more handset makers
use it), the higher the probability that documentation will have leaked.

> http://www.phonewreck.com/wiki/index.php?title=Nokia_N95#Bill_of_Materials
> RF Transceiver:
> STMicroelectronics #4380206 Quad-band GSM/GPRS/EDGE, Dual-band UMTS/HSPDA (Unmarked)

STMicro (and now ST-Ericsson) build a number of modem designs, including
at least one design from Nokia.

> DSP/BIOS 5.x Real-Time Operating System          DSPBIOS5

the dsp-bios once again runs on the application processor
> 
> http://en.wikipedia.org/wiki/Base_Band_5
> 
> Nokia BB5 General information ;)
> http://forum.gsmhosting.com/vbb/showthread.php?s=34c3b939b47546c9d6c523bb369dd92c&t=855490

exactly, that's what I've been talking about :)

So to be frank: If somebody wants to work on GSM baseband software:
choose baseband processors that are old, originate from smaller [ODM]
manufacturers.

Modern baseband processors have crypographically signed code (and corresponding
bootloaders), and its much more difficult to find any documentation and/or
source.

I personally believe the most attractive target after the Ti Calypso (and
related) family is the Mediatek (MTK) family, i.e. MT622x based chipsets.
There are literally hundreds of smaller chinese companies manufacturing the
phones, and you can easily find schematics of the reference designs as well as
data sheets / reference manuals of the baseband processor.

Regarding the wiki:  Please don't put information about random phones in it,
as it will just add noise and raise the impression tha tthose phones are
supported.

Cheers,
	Harald
-- 
- Harald Welte <laforge at gnumonks.org>           http://laforge.gnumonks.org/
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