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Modem

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Revision as of 22:28, 16 August 2021 by Begs (talk | contribs) (Adapt ModemManager mobile broadband instructions from Minecrell's gist)
Note This is a work in progress document where a lot of information is still missing. Please help to expand this page!

There are two different userspace services in postmarketOS that can manage the modem:

  • oFono: Integrated in Plasma Mobile
  • ModemManager: Integrated in Phosh

Some modems might be only supported in oFono, while others are only supported in ModemManager. But usually both can be used.

oFono

oFono is integrated into the UI of Plasma Mobile. Alternatively it can be controlled using the Python oFono test scripts from the command line:

$ sudo apk add ofono-scripts
$ /usr/lib/ofono/test/enable-modem
$ /usr/lib/ofono/test/online-modem
$ /usr/lib/ofono/test/list-modems

Check if the SIM card shows up. If you have a dual SIM Qualcomm device (e.g. Wileyfox Swift), follow this guide.

Unlock the SIM card:

$ /usr/lib/ofono/test/enter-pin pin <pin>

Eventually, your SIM card should show up as registering in /usr/lib/ofono/test/list-modems.

ofonoctl is also very useful test tool:

$ sudo apk add ofonoctl
$ ofonoctl list

SMS

Use the send-sms and receive-sms test scripts (from ofono-scripts package).

$ /usr/lib/ofono/test/send-sms "COUNTRYCODENUMBER" "Test SMS from oFono" 0
Send message using modem /gobi_0 ...
/gobi_0/message_9914F33A7C53DD6F080B38755E7D64FD59EA8F8F

ModemManager

ModemManager is integrated into the UI of Phosh. Alternatively it can be controlled using mmcli from the command line:

# List modems
$ sudo mmcli -m 0
# Enter pin
$ sudo mmcli --sim 0 --pin <pin>

Signal strength information can be viewed by using the following commands:

# Set the interval
$ mmcli -m any --signal-setup=120
# Get the information
$ mmcli -m any --signal-get

SMS

How to test SMS functionality with ModemManager:

$ sudo mmcli -m 0 --messaging-create-sms="number='+xxxxxxxxxx',text='Hello from MM'"
Successfully created new SMS: /org/freedesktop/ModemManager1/SMS/0

$ sudo mmcli -m 0 -s /org/freedesktop/ModemManager1/SMS/0 --send
successfully sent the SMS
Note number format is important, use correct format for example starting with "+xxxx"

Mobile Data

To set up mobile data in command line with ModemManager:

  • Make sure ModemManager is started (sudo rc-service modemmanager start).
  • If your SIM is locked, make sure to enter PIN (see above).
  • Check if there is rpmsg0 in output of mmcli d.
  • Create network connection for modem:
$ nmcli c add con-name "modem" type "gsm" ifname "rpmsg0" auto-config "TRUE"

If autoconfig doesn't work, adjust this command to use your ISP's apn etc.

  • Enable the network connection: nmcli c up modem.
  • Check if you get a IP address assigned in ip addr (interface rmnet0).
  • Try to ping something (e.g. ping 8.8.8.8).

NetworkManager will then connect mobile network automatically when it's available.

See also https://gist.github.com/Minecrell/4cc2bfb9fcae18e294386b0a213907d1 for oFono instructions.

Qualcomm Modems

On most Qualcomm SoCs the modem is a separate processor which lives next to the main CPU where Linux is running on. It needs to be given firmware by the host processor to start.

The procedure for getting the modem to work is generally the following:

  • Package and install the Firmware of your modem into the file system, generally the mba.* and modem.* files.
  • Install the package msm-modem-downstream or msm-modem-rpmsg (for most older SoCs on mainline, see below), depending on the kernel you are using (and reboot to activate the udev rules and services).
  • Install ofono and start it using rc-service ofono start
  • You should see signs of your firmware being loaded in the dmesg.
  • You can use the ofono test scripts (packaged in ofono-scripts or ofonoctl to see if the Linux recognized your modem and if it works correctly.
  • On some platforms you may need to manually install msm-modem-uim-selection, see Dual-Sim QMI page for some details.

Note: On newer SoCs (e.g. SDM845 or MSM8953), the modem seems to be available only through QRTR, and not through rpmsg channels as on older Qualcomm SoCs. You can see this if qrtr-lookup also lists modem services such as User Identity Module service. In that case, you can query the modem through libqmi 1.26.0+ like qmicli -d qrtr://<node> --uim-get-card-status (get <node> from the qrtr-lookup output). Currently, the QRTR transport does not seem to be supported in modem services like oFono or ModemManager yet. At least for ModemManager there seem to be ongoing efforts to make it work, though. See SDM845 Modem for details and example output.

Troubleshooting

When switching UI

Ofono and ModemManager cannot run at the same time. If you switch UI from Plasma Mobile to Phosh, or vice versa, you might have to make sure that only the correct userspace service is running.

Getting ModemManager logs

1. Open /etc/init.d/modemmanager with your favorite text editor with root permissions

2. Enable debug mode by changing the command_args line to command_args="${modemmanager_opts} --debug --log-level=DEBUG"

3. Output the logs to /var/log/modemmanager.err by adding error_log="/var/log/modemmanager" to the same file.

4. Save and restart ModemManager with `rc-service modemmanager restart`

5. The logs will now be available at /var/log/modemmmanager.err. Note that they contain sensitive information such as your phone number(s), IMEI, etc.! Scrub them when uploading these logs to the Web!

Also note that the logs may take up a lot of space if you leave them running for a long time.


Example of /etc/init.d/modemmanager

 #!/sbin/openrc-run
 
 supervisor=supervise-daemon
 command=/usr/sbin/ModemManager
 command_args="${modemmanager_opts} --debug --log-level=DEBUG"
 error_log="/var/log/modemmanager.err"
 
 description="ModemManager Daemon"
 
 depend() {
    need dbus
 }

Getting eg25-manager logs

This only applies to the PinePhone.

1. Open /etc/init.d/eg25-manager with your favorite text editor with root permissions

2. Output the logs to /var/log/eg25-manager.err by adding error_log="/var/log/e25-manager" to the same file.

4. Save and restart eg25-manager with rc-service eg25-manager restart

5. The logs will now be available at /var/log/eg25-manager.err.


Example of /etc/init.d/eg25-manager

 #!/sbin/openrc-run
 
 supervisor=supervise-daemon
 command=/usr/bin/eg25-manager
 error_log="/var/log/eg25-manager.err"
 
 description="EG25 Manager Daemon"

usbmon logs

The Linux kernel allows you to capture QMI and AT commands over USB using usbmon and can be read using Wireshark. See this page to use it: https://wiki.postmarketos.org/wiki/Create_usbmon_capture

Relevant issues

  • #520 N900: integrate ofono
  • #598 Let's get the cellular modem working! (presenting various stacks, general discussion)
  • #1054 Get qualcomm modems working (at the end of the thread scintill wrote a few wrappers and made SMS on a QC modem work with a downstream kernel without userspace blobs!)
  • #1314 i9195/Qualcomm modem support (scintill's work integrated)
  • pmaports#251 xiaomi-santoni: gets modem to work on the device

Relevant pages

See also