[Replicant] Replicant status and future Was: Is the Galaxy S3 going to be forcefully obsoleted on 7/1/22?

Denis 'GNUtoo' Carikli GNUtoo at cyberdimension.org
Wed Jan 19 18:01:32 UTC 2022


On Sat, 15 Jan 2022 13:27:57 -0500
"A. F. Cano via Replicant" <replicant at osuosl.org> wrote:
> My phone is a Samsung Galaxy S (not an S3 - an SGH-T959 running a
> really old version of Cyanogenmod) but I've been trying to buy an S3
> to put Replicant on.  I have tried twice.  The first time, after a 3
> month wait, I received the wrong phone from China.  The second time I
> received an S3, but it wasn't a GT-I9300, it was a useless to
> Replicant SPH-L710.
> 
> Not knowing the actual capabilities of the S3 wrt cell networks, I
> went looking.  This review:
> 
> https://www.gsmarena.com/samsung_i9300_galaxy_s_iii-review-761.php
> 
> says:
> 
> Quad-band GSM and quad-band 3G support
> 21 Mbps HSDPA and 5.76 Mbps HSUPA support
> 
> It seems pretty obvious that the first part is not going to be useable
> after 7/1/22, but will the S3 still be useable after that thanks to
> the second part?  Will T-Mobile still support "Quad-band GSM" after
> 7/1/22?
> 
> If the S3 is going to become totally useless after 7/1/22, what
> options remain for us replicant hopefuls after the 3G network goes
> dark?
It's possible that the GSM protocol will continue to work (though you'd
need to check that). 

If that's the case means that you could still call and send/receive SMS.

For getting Internet through the GSM network, there are two possible
scenarios (you'll have to check that too):
- If there is still GPRS you might be able to get Interent through
  that, but that is extremely slow and it has huge latency, so it's
  probably close to unusable nowadays. You'll also need to check if the
  operator doesn't charge more for using GPRS.
- There might also be no data connection that works anymore.

> I understand that the GT-I9305 is still not working properly with
> replicant.
The code has not been integrated yet so we can assume that.

> I'm even considering a pine phone pro, but that's not yet available
> and is a totally different animal.
> 
> https://www.pine64.org/pinephonepro/
We've not looked yet at the Pinephone PRO.

As for the Pinephone (not pro) and the Librem5, we're working on
porting Replicant to Android 11 and to use kernels based on upstream
Linux.

The idea was to do the port with the GT-I9300 first (and to add support
for the pinephone and librem5 later on), as:
- many Replicant users already have it, and when it'll start working
  they could help with testing too
- we can also do regression tests between Replicant 6 and Replicant 11
- and a lot of work were already done by various people to add support
  for it in mainline Linux.  
- the GT-I9300 is well known and we know that the hardware is capable
  of a good enough battery life (~1 day of non contiguous usage)
- we can also collaborate with other distributions like postmarketOS
  and with people trying to add it back in LineageOS
- GT-I9300 can be found cheap second hand and batteries are still
  available.

If we look at the Pinephone (not pro) the main issue right now is that
the battery life is short, so users can't use the phone much if they
don't recharge it during the day. This is probably because the software
(kenrel power management, and so on) is not obtimized enough yet, and
it will hopefully be fixed at some point, but we have no guarantees on
that.

And that might be hard too: with the GTA04 (a similar phone that isn't
produced anymore), it required a lot of work and a very precise
infrared camera to find out that the UART was left on during suspend,
to improve battery life.

With the Librem5, later revisions seem to have a bigger battery, so
I assume that the battery life is good enough, but the device is way
too expensive for most users, so it can't be the only device supported
by Replicant.

The issue is that even if this work to port Replicant on Android 11
with kernel based on upstream Linux is being funded by NLnet and that I
got some help with the Android part, I still didn't manage to make the
GT-I9300 modem work, and even if I've not exausted all paths to make it
work, I already spent a lot of time trying and I didn't manage to fix
the issue I have (I can boot the modem but it doesn't register to the
network, it's probably stuck in low power mode somehow).

> Considering the end of the 3G network, what is the preferred phone for
> replicant now?  Is Replicant going to be murdered by planned
> obsolescence?

I vagely recall that the GT-I9305 wasn't compatible with all the
operators in the USA either (because it doesn't supports all the
frequencies), so adding support for it in one way or another will
probably not fix the issue.

So the question for Replicant is what to do now. In any case we still
need to port Replicant to Android >= 11 and use kernels based on
mainline.

My current plan is to try new approaches for the modem:
- Port part of the intialization and power management from the kernel
  to libsamsung-ipc in userspace and make it work on Replicant 6, and
  then hope that it would also work in Replicant 11.
- Try to get more logs and information from the modem (through
  something like xgoldmon) and/or get more debugging information in the
  drivers and/or enable to see the full protocol trace in wireshark
  (so I'd need to add a disector for the samsung-ipc protocol and
  capture the full exchange by sniffing the USB in both Replicant 6 and
  Replicant 11 and compare both).
- Someone also managed to make it work on a Galaxy S, but there is a lot
  of differences as it use share memory. So I've imported some of the
  patches of that port but it didn't fix the issue I had. I could also
  look more in that direction to understand if I've the same bugs, and I
  could also try to see the differences betweeen that code and the code
  that I'm using.
and to finish that port, hoping that we get power management right.

If that doesn't work out we'll probably need to switch to the Pinephone,
because even if the battery life is not great it will get Replicant
going.

> I'm so totally fed up with locked phones that I'm now considering
> spending amounts of money that would have seemed outlandish months
> ago, like for the pine phone pro.
> 
> Totally disgusted by the phone software situation on modern phones.
That's also the issue we have with Replicant, last time I checked none
of the phones supported by LineageOS had an isolated modem and a
battery that could be replaced[1].

So our only option is to make Replicant use a mainline kernel in one
way or another and also have more recent Android versions, but that
might take quite some time.

Right now I've taken a small break from all that work to concentrate on
more urgent things that didn't advance fast enough (because everybody,
me included was busy, so it advanced way too slowly):
- Finish the paperwork needed to hire the community manager.
- Finally make that Replicant 6.0 0004 release.

Then I plan to see again what to do with the GT-I9300 modem and also
work with the Replicant steering commitee and the community manager on
defining collectively how to use the Replicant funds to fund
development to get that work finished in one way or another (if the
device is a pinephone instead of a GT-I9300 it also works).

The nice thing about Nlnet funds is that there is a very low overhead
from both the person doing the work and NLnet, but what makes that low
overhead possible is that you are only paid when group of tasks are
done[2]. And for work of this type it's really hard to predict how much
time taks will take. So you typically need to combine that fund with
other funding sources (like your own money, donnations, etc) to fil
the potential gaps to make it work well.

Here the issue is that most of the groups of tasks depends in one way or
another on the modem working, and I didn't get it working yet, so at
some point I'll run out of money way faster than anticipated.

The other nice thing about NLnet funding is that if something doesn't
work out, you can also change the tasks details if you keep a similar
goal, so here I could probably change the GT-I9300 with a Pinephone,
but in that case I would also have to do a lot of work to make the
modem work.

oFono already has support for some Quectel modems, and the Pinephone
uses a Quectel EG25-G, and for the qualcomm modem protocol, so I might
need complete the support for it, and then I'd need to integrate the
oFono RIL in Android 6 and then 11 (It was meant for Replicant 6 so it
might be faster to do it this way, as I could do regression testing).

As for using oFono instead of ModemManager (which is what is being used
on devices like the Pinephone or Librem5 these days), I'm not aware of
any projects having integrated ModemManager in Android. In
addition there are patches to add support for libsamsung-ipc oFono in
oFono and it also integrates better with testing (If one day we manage
to make OsmoGSMTester[2] work for Replicant, oFono is already
used with OsmoGSMTester).

References:
-----------
[1]The tablets supported by Replicant don't have removable batteries
   but they are replaceable quite easily: you need a bit of practice to
   open the tablets, and once that's done you can replace the
   batteries. In contrast many modern smartphones can't be opened easily
   without damaging the plastic: everything is glued and generic
   equipement like a heat gun isn't sufficient to do it right easily.
[2]https://osmocom.org/projects/osmo-gsm-tester

Denis.
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