Deleting SMS from SIM on OpenMoko

Posted on 2019-11-29 by Chris Warburton

I had an annoying problem recently with my OpenMoko FreeRunner: I wasn’t receiving SMS messages, and the home screen was showing the confusing message Texto Plein. I don’t recall this ever happening before, despite using this ’phone for a decade.

I thought I’d write up how I solved this, to help anyone else who may encounter this problem in the future (which, let’s face it, is probably just me ;) )

Identifying the Problem

The string Texto Plein didn’t look English to me. Since my FreeRunner is using the QtMoko distribution (essentially Debian plus QtExtended) I tried searching Google for the query "texto plein" qtmoko. This gave exactly one hit, which is the source code of the theme (yet another reason to use FOSS!).

Searching for Texto Plein in this file I saw these lines (which I’ve cleaned up and indented):

<text rect="0,0,0x9pt"
      align="hcenter"
      bold="yes"
      color="#ffffff"
      outline="#000000"
      transient="yes"
      active="expr:@/Telephony/Status/SMSMemoryFull > 0 &amp;&amp; @/Communications/Messages/NewMessages == 0">
  Texto plein
</text>
<text rect="0,50%,0x9pt"
      align="hcenter,bottom"
      bold="yes"
      color="#ffffff"
      outline="#000000"
      transient="yes"
      active="expr:@/Telephony/Status/SMSMemoryFull > 0 &amp;&amp; @/Communications/Messages/NewMessages > 0">
  (Texto plein)
</text>

Ignoring all of the styling, the important part seems to be the active attribute, which in both cases contains

expr:@/Telephony/Status/SMSMemoryFull > 0

(Side note: one of the reasons I’m not partial to XML is that despite all of the ceremony and hoop-jumping-through it requires, the benefits are often lost due to the reliance on weird sub-languages contained in string attributes. It’s a “path of least resistance” for smuggling through structured data without having to invent a verbose bunch of tags, schemas, etc. Even the XML standards themselves are guilty of this, with XPath being a classic example. In this case it’s made even worse by the need to XML-encode the &&! I think s-expressions make this less tempting, since they’re already terse.)

From this, it looks like our SMS memory is full. Despite deleting all of the messages in the QtMoko messaging program, the Texto Plein warning remained. It turns out the real problem is that the message storage on my SIM card is full!

False Starts

Looking through the QtMoko changelog, mailing list and bug tracker there are some mentions of SIMs getting full; with different QtMoko versions opting to delete from the SIM or not, as different users complain.

My QtMoko version was out of date, so I tried installing the latest version. It didn’t help.

I tried connecting to the modem via a serial terminal, and sending the appropriate “AT commands”. Whilst I could talk to the modem and run certain commands successfully, the SMS deletion commands gave errors.

The Solution

One annoyance with QtMoko is that the Qt application takes over complete control of the GSM modem, and as far as I can tell it doesn’t have a simple commandline or scripting method.

In contrast, the “official” OpenMoko operating systems used a much more extensible/hackable approach: producing the freesmartphone.org platform which listens on DBus for specified commands. I installed the SHR system on to a spare microSD card and used that to boot my phone.

After stepping through the first-run wizard, I set a root password, opened a terminal to give myself a static IP address via ifconfig and logged in from my laptop over a USB cable (this is far nicer than picking at keys on the touchscreen, and also lets me use Emacs to run the terminal :) ).

It turns out that I didn’t even need to mess with DBus directly, since SHR comes with a handy (Python-based?) commandline program called cli-framework which sets up all of the boilerplate, allowing the calls from the freesmartphone.org spec to be called directly:

$ ssh root@phone
 ____  _  _  ____        ___  __  ____  ____
/ ___)/ )( \(  _ \ ___  / __)/  \(  _ \(  __)
\___ \) __ ( )   /(___)( (__(  O ))   / ) _)
(____/\_)(_/(__\_)      \___)\__/(__\_)(____)
root@om-gta02:~# cli-framework
DBus Exception. dbus-hlid not installed
DBus Exception. dbus-hlid not installed
DBus Exception. dbus-hlid not installed
failed to connect to bluez
freesmartphone.org interactive command line
>>> dir()
[   'INTROSPECT',
    'MainLoop',
    '__builtins__',
    '__doc__',
    '__file__',
    '__name__',
    '__package__',
    '__version__',
    'atexit',
    'bluez_manager',
    'bus',
    'code',
    'console',
    'dbus',
    'dbus_hlid',
    'dbus_to_python',
    'devaudio',
    'devidle',
    'devrtc',
    'events',
    'framework',
    'frameworkiface',
    'getInterface',
    'getObject',
    'getObjectsForInterface',
    'gps',
    'gpsaccuracy',
    'gpsposition',
    'gpssatellite',
    'gpstime',
    'gsm',
    'gsmcall',
    'gsmcb',
    'gsmdata',
    'gsmdebug',
    'gsmdevice',
    'gsmhz',
    'gsmmonitor',
    'gsmnetwork',
    'gsmpdp',
    'gsmphone',
    'gsmrtc',
    'gsmsim',
    'gsmsms',
    'gsmtest',
    'handler',
    'leds',
    'mainloop',
    'muxer',
    'network',
    'os',
    'phone',
    'pim',
    'pimc',
    'pimcq',
    'pimm',
    'pimmq',
    'pims',
    'pp',
    'pprint',
    'preferences',
    'prettyPrint',
    'readline',
    'rlcompleter',
    'runmainloop',
    'sys',
    'testing',
    'timealarm',
    'types',
    'ubxdebug',
    'usage',
    'usageiface']

It looks like we want gsmsim which, according to the spec, provides a GetSimInfo method:

>>> gsmsim.GetSimInfo()
{   'imsi': '...',
    'issuer': 'unknown',
    'phonebooks': 'emergency aux:BD fixed aux:DC dialed received aux:LR aux:MT aux:AD contacts aux:SD missed aux:LM aux:AF own aux:UD',
    'slots': 10,
    'used': 10}

I’ve elided my serial number, but we can see I have 10 SMS slots in total, and all 10 of them are used.

Now let’s use the DeleteMessage method:

>>> gsmsim.DeleteMessage(1)
>>> gsmsim.GetSimInfo()
{   'imsi': '...',
    'issuer': 'unknown',
    'phonebooks': 'emergency aux:BD fixed aux:DC dialed received aux:LR aux:MT aux:AD contacts aux:SD missed aux:LM aux:AF own aux:UD',
    'slots': 10,
    'used': 9}

This seems to work! Let’s do the rest (they turn out to count up from 1):

>>> gsmsim.DeleteMessage(2)
>>> gsmsim.DeleteMessage(3)
>>> gsmsim.DeleteMessage(4)
>>> gsmsim.DeleteMessage(5)
>>> gsmsim.DeleteMessage(6)
>>> gsmsim.DeleteMessage(7)
>>> gsmsim.DeleteMessage(8)
>>> gsmsim.DeleteMessage(9)
>>> gsmsim.DeleteMessage(10)
>>> gsmsim.GetSimInfo()
{   'imsi': '234103410021965',
    'issuer': 'unknown',
    'phonebooks': 'emergency aux:BD fixed aux:DC dialed received aux:LR aux:MT aux:AD contacts aux:SD missed aux:LM aux:AF own aux:UD',
    'slots': 10,
    'used': 0}

We’ve freed up the SIM’s memory, so now we can switch back to the QtMoko microSD, and hopefully it won’t happen again!