Running mm-control

Client applications don't need to explicitly start the mm-control service before performing media operations. The QNX CAR platform uses the System Launch Monitor (SLM) service to start mm-control during bootup; this ensures mm-control is running when the HMI loads and users begin interacting with its applications. For recovery purposes, applications can start mm-control manually.

Starting mm-control with specific command options during bootup

SLM automates process management by launching processes in an order that respects their interprocess dependencies. The list of processes to launch and their properties, including their command-line arguments and interprocess dependencies, is written in a configuration file. During bootup, SLM reads this file and carries out its instructions for starting processes.

Using SLM to start mm-control ensures the car infotainment system is ready to process media commands when the HMI finishes loading. For more information on SLM, refer to the Getting Started Guide for the QNX CAR application platform 2.0 RR.

SLM is preconfigured to start mm-control with specific command options, but you can specify whatever command options you want.
To change the command options passed by SLM to mm-control:
  1. From a command console connected to your car system, navigate to and open the SLM configuration file, whose default path is: /etc/slm-config-all.xml.
  2. In the configuration file, locate the component that specifies the properties for mm-control. This component is the <SLM:component> XML object with the name "mmcontrol".
  3. Change the value of the <SLM:args> tag in the "mmcontrol" component to hold the new set of command-line options to pass to mm-control at startup. For the full list of command-line options, see the mm-control command line section.
  4. Save the changes to the SLM configuration file and return to the console.
  5. If you want the new configuration to take effect immediately, enter reboot in the console. The system reboots and the SLM utility relaunches all the processes, including mm-control, with the command options specified in the configuration file. When the system finishes reloading, mm-control is running with the new configuration.

    If you don't reboot after changing the configuration file, mm-control continues to run with its previous configuration until you shut down the system and restart, at which point the new command options take effect.