A CoreSight framework and CoreSight trace component drivers for Linux have been introduced. ARM's CoreSight provides on-chip debug and trace capabilities.
As described at ARM.com
by ARM Holdings, "ARM CoreSight products include a wide range of trace macrocells for ARM processors, system and software instrumentation and a comprehensive set of IP blocks to enable the debug & trace of the most complex, multi-core SoCs. ARM has defined an open CoreSight architecture to allow SoC designers to add debug & trace capabilities for other IP cores in to the CoreSight infrastructure."
The CoreSight Linux kernel patches are currently under a "request for comments" state and includes CoreSight trace components for Sources, Links, and Sinks.
For those interested in this ARM debugging technology, see the CoreSight thread
on the Linux kernel mailing list.