First small steps toward free GSM firmware

[Michael Spacefalcon]

"dmatthews.org" <mail at dmatthews.org> wrote:

> This is something I've quietly had an interest in for a year plus.

Yup, I remember you from 2011. :-)

> I'd like to suggest that it would be beneficial not only to have some hand
> holding for people that want to compile, but also sample binary for those of
> us that may not have easy access to necessary hardware and software.

Compiling the leo2moko version of the GSM fw from the semi-src does
not require any special software, let alone hardware: the hardware is
any regular PC, the software is your favourite GNU/Linux distribution
with working Wine.  Nothing more is needed: if you have a system with
working Wine, just unpack my tarballs and run the winebuild.sh script.

However, having a prebuilt binary of the leo2moko GSM fw (to encourage
prospective testers from the shy-land) does sound like a good idea, so
I have just put one out:

ftp://ftp.ifctf.org/pub/GSM/FreeCalypso/leo2moko-r1-bin.tar.bz2

Or was your reference to "necessary hardware and software" regarding
the flashing process, rather than compiling the gsm-fw.m0 image
itself?

Regarding the flashing process, I do agree that the current barrier to
entry is still a little too high and could use some lowering.  As
things stand right now, if you want to do your own flashing operations
on the GSM modem in your GTA02, the following skills/tools are
required:

1. Whatever distro you are running on your FR, you need to know it
   inside out: you need to know how to ssh into your phone, how to
   kill gsmd or whatever process talks to the modem (and to ensure
   that it doesn't get restarted until you are done flashing your new
   fw and wish to test it live), and how to twiddle the power_on and
   download controls for the modem under /sys, as appropriate for
   whichever GTA02 kernel version you are running.

2a. You need to be able to cross-compile my fc-loadtool utility to run
    on the application (Linux) processor of your GTA02, and do it in a
    way that will be compatible with your distro from the previous
    paragraph.  (I could send you my binary, built with some
    CodeSourcery toolchain for my Buildroot AP environment, but I
    doubt that one would be able to just plop it into SHR or QtMoko or
    whatever, and have it "just work".)

-or-

2b. You need to buy a "T191 unlock" cable that would plug into your
    Neo's headset jack - in that case you would be able to run
    fc-loadtool from your GNU/Linux PC, removing the need to build it
    for running from inside the Neo.  But even with this magic cable,
    you would still need to satisfy requirement 1 above: you still
    need to ensure that there is no gsmd etc running, and you'll need
    to twiddle the download and power_on modem sysfs nodes by sshing
    into the phone.

I'm thinking that one possible way to lower this entry barrier would
be to produce and publish a bootable SD card image with the following
features:

* A known environment, eliminating the "whatever FR distro you happen
  to be running" factor;

* Specifically designed for manual poking at the GSM modem - no gsmd
  and no "normal" functionality;

* Have the special Linux image come up with the headset jack serial
  channel enabled and with the device screen showing pressable buttons
  for "Modem ON" and "Modem OFF" - thus anyone using the headset jack
  serial cable method would have no remaining barriers;

* Have the image also come up with ssh access via USB enabled, and
  have fc-loadtool and some other tools already available inside -
  thus anyone using the sans-special-cable method would be able to ssh
  into the phone in a known way and run commands which can be given
  verbatim with no sophisticated preparations needed.

Producing a Linux image like the above won't be an overnight deal, but
it is something that I can work toward.

> I might have had some qualms about repercussions of using this software
> in Europe,

Why?  The radio transmissions from the illegally-free fw are strictly
identical to those produced by the original (presumably legal) mokoN
firmware, so how would anyone ever detect that you are using my
illegally-free fw?  The physical appearance of the device (as would be
seen by a cop pulling you over on a highway for driving too fast or
whatever) also does not change with illegal fw flashing, so if the
device looked like a legal cellphone originally, it will still look
the same...

> I'd be able and would love to test once this effort approaches some level
> of maturity.

Ahmm, asking for "some level of maturity" before one is willing to
even *test* a piece of software is rather dysfunctional.  How would
the sw *ever* reach any level of maturity without some people testing
it early on, reporting their experiences, sending bug reports etc?
Therefore, *someone* needs to be willing to act as an adventurous
alpha tester, trying out what exists currently.

I do concede though that the barrier to entry for prospective testers
needs to be lowered, so I won't be holding my breath for any alpha
testers to come forward until I produce and publish the SD card image
I have proposed earlier.

VLR,
SF