The usblauncher Service Parent topic: The usblauncher Service

Command line for usblauncher

Start usblauncher device enumerator and publisher

Synopsis:

    usblauncher [-b] [-C] [-c config_file] [-e] [-h] [-l] 
        [-M mnt_rules] [-m pps_path] [-n stack_name] [-P] 
        [-p seconds] [-r] [-S stack_number] [-s dll_path] [-t] [-v]

Options:

-b
Run usblauncher in the foreground. This option is handy for debugging because you can press Ctrl–C to terminate the publisher.
By default, usblauncher runs in the background.
-C
Always set the device configuration when attaching a device. This option should be used alongside the io-usb -C option, which tells the USB stack never to set the device configuration at enumeration time. Note that this stack option doesn't affect hubs—their configurations are always set by the stack.
We recommend using the -C option for both usblauncher and io-usb when supporting MirrorLink devices, which will make usblauncher set the configuration after sending the NCM request.
By default, usblauncher selects a configuration only for devices with multiple configurations, based on the first driver that matches the device.
-c config_file
The configuration file. At startup, usblauncher reads this file to learn the USB device-matching rules for different device types. These rules indicate which driver to launch for communicating with the device as well as which command options to provide to the driver.
If you don't specify a configuration file, usblauncher looks for the default file (/etc/usblauncher/rules.lua). In this case, the default file must exist or usblauncher won't run.
The configuration file named with this command option can include other Lua files by using the dofile() command. For example, if you use separate files to define various descriptors to use when running in USB device mode, you can include these descriptor files in the main configuration file.
-e
Enable detection of extra events; specifically, bad device attachments and detachments as well as device resets.
By default, usblauncher doesn't detect and publish information about these extra events.
-h
Prevent the USB stack from starting in host mode, which is the default behaviour. Use this option when you want to support OTG but your client application will decide which stack version to start and then issue the start_stack command through PPS to tell usblauncher when to start a stack.
-l
Log messages to sloginfo instead of standard out.
By default, usblauncher logs messages to standard out.
-M mnt_rules
The mountpoint file, which tells usblauncher where to mount the filesystems of devices represented by particular /dev entries. Any file named with this option must be in the same format as the default mcd mountpoint file (/etc/mcd.mnt). In this file, you can name not only mountpoints but also the mount options provided to the filesystem library, such as codepage mapping or long-filename handling in fs-dos.
Use the -M option if you want to assign nondefault mountpoints to devices. You can also name an empty file to prevent usblauncher from mounting USB devices (see "Disabling usblauncher auto-mounter" for details).
-m pps_path
The PPS directory path. The subdirectories for storing the device, device control, driver, and mount objects are located in this directory. The default is /pps/qnx/.
-n stack_name
The server name of the USB stack. The default is /dev/io-usb/io-usb. Use this option only if you don't support OTG and always run the USB host stack (io-usb), never the USB device stack (io-usb-dcd), and if your USB host stack is stored at a nondefault location.
If you want to support OTG and use nondefault USB stack paths, you must define these paths in the Host_Stack and Device_Stack rules in the configuration file.
-P
Probe the media to get the partition count only if the device is ready.
By default, usblauncher doesn't wait until the device is ready to try to obtain the partition count.
-p seconds
The polling interval (in seconds), which is how often usblauncher checks for changes to the mountpoints associated with the active drivers.
The default interval is three seconds.
-r
Treat a device suspension event as a cable removal event. Some devices don't generate removal events, so you can set this option to make usblauncher terminate the USB device stack after receiving a suspension event following a configuration event.
-S stack_number
The USB stack number. The usblauncher service stores this value in the information for each USB device it monitors, to differentiate the device from others that have the same bus number and device number but are managed by other io-usb servers.
-s dll_path
The plugin path. At startup, usblauncher looks in this path for plugins it can load and then use to provide more detailed device information (see "Media Player Plugins").
If this option isn't specified, no plugins are loaded.
-t
Terminate launched drivers when exiting.
By default, usblauncher doesn't terminate driver processes while deleting device and driver objects during shutdown.
-v
Increase output verbosity. The -v option is cumulative, so you can use several v's to increase verbosity. Setting one v logs USB device attachments and detachments. Setting two v's adds the logging of PPS object creation and deletion. Setting three or four v's logs more detailed events as well as errors that are less severe.
Output verbosity is handy when you're trying to understand the operation of usblauncher. However, when lots of -v arguments are used, the logging becomes quite significant. The verbosity setting is good for systems under development but probably shouldn't be used in production systems or during performance testing.

Description:

Note: You should start usblauncher with an explicit command only if the process terminates unexpectedly. Before trying to start usblauncher manually, always confirm that the process isn't already running by checking the list of active processes with pidin or ps. If you want to restart only the USB stack, send the start_stack command to the device control object.

The usblauncher command starts a multipurpose service that enumerates USB devices, launches drivers for communicating with those devices, and publishes their information through PPS.

On the command line, you can override the default configuration file to provide usblauncher with a set of custom rules for configuring different device types. You can also name your own mountpoint file to mount filesystems to nondefault locations, set how often usblauncher checks for mountpoint updates, and configure how it logs error and event information.

By default, usblauncher starts the USB stack in host mode, assuming you've defined the appropriate rules in the configuration file. You can prevent the launching of this stack by using the -h option, if you plan to use your system as the USB device.

The usblauncher service runs as a self-contained process that doesn't require any user input. It has no client utility for performing device-publishing tasks on request or for adjusting any of its settings. You can restart the USB stack in a different role by issuing the start_stack command through PPS, but to reconfigure usblauncher in any other way, you must change the options in its command line and restart the service. We recommend putting the usblauncher command line in a startup script (e.g., startup.sh) to automatically launch the service during bootup.

Parent topic: The usblauncher Service