Re: Usign MM inside Quectel EC21/25 or similar mdm9x07 modem device

[Nikita Orlov]

I managed to get qmicli working with /dev/smdcntl0 device via qmi-proxy --no-exit

(due to issue described here https://gitlab.freedesktop.org/mobile-broadband/libqmi/-/issues/51)

 

I can ge wds service connected, but still can't bind port to rmnet_data0, some more debugging needed.

 

Also I found qcom-soc plugin in MM, seems some /dev/smdcnt0 as qmi port and /dev/sdm8 as at port

can be added there, but not clear how to add port binding.

 

Looking for any help.

 

24.12.2021, 15:53, "Nikita Orlov" <nikitos1...@yandex.ru>:

Hello!

 

I am doing research about using Quectel EC21/EC25 devices as IoT module,

means using it as standalone computer without any external host PC.

 

At the moment I archived minimal Buildroot based build including Linux kernel

and several qualcomm software packages (irsc_util, netmgrd, qmuxd, dsi_netctrl library based data connection app).

I can run it on the EC25-EU and get internet connection via rmnet_data0.

 

The flow seems to be following:

1) run irsc_util to setup AF_MSM services some permissions

2) run netmgrd, it do some magic (I haven't track sources mostly yet) to expose /dev/smdcntl0

and rmnet0, rmnet_dataX network interfaces.

3) run qmuxd with qmiserial2qmuxd (https://github.com/scintill/qmiserial2qmuxd)

 

After I can access modem (means internal hexagon DSP) via

- /dev/smd8 (AT command, actually available right after hexagon is loaded),

- qmi commands (via qmicli/uqmi -> qmiserial2qmuxd -> qmuxd -> /dev/smdnctl0)

 

I can archive internet connection via some dsi_netctrl_test application

(as result I have rmnet_data0 interface brought up with ipv4 address)

 

or

 

I can start connection via --wds-start-network="internet"

and also get modem connected. --wds-get-current-settings

show me ip addresses, DNS and so on.

 

But I don't know how to bind internal data channel to linux rmnet_dataX interface.

 

So, I have two questions:

1) Where can I read, ask about QMI control conceptions, about some virtual channels, port binding and so on?

2) How do you think it possible, reasonable to add some support to MM to allow it to be executed inside modem env

(as all things now supposed to work with external modem on host PC).

 

The reason for this research as such modem modules can be used for cost effective (no additional host pc/mcu)

IoT solutions, but there is no good sw platform for such projects. Besides build env, OTA updates, loaders, thermal

and power consumption control, the main thing is core data connection functionality managment.

Voice calls and host controls can be omitted in such cases.

 

P.S. Sorry for maybe dummy questions, but I still don't know much about modem topics and things around

 

-- 

Nikita Orlov

Skype: nik_stet

QQ: 2717846083

 

 

 

-- 

Nikita Orlov

Skype: nik_stet

QQ: 2717846083