USB Monitor.
+ The USB monitor is an application in the apps/system/usbmonitor that provides a convenient way to get debug trace output.
+ If tracing is enabled, the USB device will save encoded trace output in in-memory buffer;
+ if the USB monitor is also enabled, that trace buffer will be periodically emptied and dumped to the
+ system logging device (the serial console in most configurations).
+ The following are some of the relevant configuration options:
+
| + Device Drivers -> USB Device Driver Support + | +|
+ CONFIG_USBDEV_TRACE=y
+ |
+ + Enable USB trace feature + | +
+ CONFIG_USBDEV_TRACE_NRECORDS=nnnn
+ |
+ + Buffer nnnn records in memory. + If you lose trace data, then you will need to increase the size of this buffer + (or increase the rate at which the trace buffer is emptied). + | +
+ CONFIG_USBDEV_TRACE_STRINGS=y
+ |
+ + Optionally, convert trace ID numbers to strings. + This feature may not be supported by all drivers. + | +
| + Application Configuration -> NSH LIbrary + | +|
+ CONFIG_NSH_USBDEV_TRACE=n
+ |
+ + Make sure that any built-in tracing from NSH is disabled. + | +
+ CONFIG_NSH_ARCHINIT=y
+ |
+
+ Enable this option only if your board-specific logic has logic to automatically start the USB monitor.
+ Otherwise the USB monitor can be started or stopped with the usbmon_start and usbmon_stop commands from the NSH console.
+ |
+
| + Application Configuration -> System NSH Add-Ons + | +|
+ CONFIG_SYSTEM_USBMONITOR=y
+ |
+ + Enable the USB monitor daemon + | +
+ CONFIG_SYSTEM_USBMONITOR_STACKSIZE=nnnn
+ |
+ + Sets the USB monitor daemon stack size to nnnn. + The default is 2KiB. + | +
+ CONFIG_SYSTEM_USBMONITOR_PRIORITY=50
+ |
+ + Sets the USB monitor daemon priority to nnnn. + This priority should be low so that it does not interfere with other operations, but not so low that you cannot dump the buffered USB data sufficiently rapidly. + The default is 50. + | +
+ CONFIG_SYSTEM_USBMONITOR_INTERVAL=nnnn
+ |
+ + Dump the buffered USB data every nnnn seconds. + If you lose buffered USB trace data, then dropping this value will help by increasing the rate at which the USB trace buffer is emptied. + | +
+ CONFIG_SYSTEM_USBMONITOR_TRACEINIT=y+ CONFIG_SYSTEM_USBMONITOR_TRACECLASS=y+ CONFIG_SYSTEM_USBMONITOR_TRACETRANSFERS=y+ CONFIG_SYSTEM_USBMONITOR_TRACECONTROLLER=y+ CONFIG_SYSTEM_USBMONITOR_TRACEINTERRUPTS=y+ |
+ + Selects which USB event(s) that you want to be traced. + | +
+ NOTE: If USB debug output is also enabled, both outputs will appear on the serial console. + However, the debug output will be asynchronous with the trace output and, hence, difficult to interpret. +