Trace capture USB interface requirements¶
This chapter describes the requirements to enable trace capture via the
Zephelin’s USB interface. Zephelin provides an out-of-the box USB device
implementation in zpl/backends/usb_backend.c
To enable the USB interface, the user y-should select
the CONFIG_ZPL_TRACE_BACKEND_USB Kconfig option. The
CONFIG_ZPL_TRACE_BACKEND_USB option automatically selects every necessary
software component in Zephyr required to run the USB device stack.
Note
Capturing traces via the USB backend requires asynchronous tracing to be enabled.
To use it, y-select CONFIG_TRACING_ASYNC.
Driver requirements¶
A USB device driver needs to be provided for the given platform when the
USB trace capture interface is used. Make sure there is a UDC driver available
for your platform upstream (in drivers/usb/udc/), or provide your own UDC
driver implementation as described in the
Zephyr documentation.
Devicetree requirements¶
The USB device implemented by Zephelin expects the zephyr_udc0 node to be
present in the devicetree file. Make sure the platform devicetree file provides
a valid chosen node with the zephyr_udc0 property defined. The property
under /chosen/zephyr_udc0 should point to a platform USB controller node.