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- .. SPDX-License-Identifier: GPL-2.0
- ==============================
- Trace Buffer Extension (TRBE).
- ==============================
- :Author: Anshuman Khandual <anshuman.khandual@arm.com>
- :Date: November 2020
- Hardware Description
- --------------------
- Trace Buffer Extension (TRBE) is a percpu hardware which captures in system
- memory, CPU traces generated from a corresponding percpu tracing unit. This
- gets plugged in as a coresight sink device because the corresponding trace
- generators (ETE), are plugged in as source device.
- The TRBE is not compliant to CoreSight architecture specifications, but is
- driven via the CoreSight driver framework to support the ETE (which is
- CoreSight compliant) integration.
- Sysfs files and directories
- ---------------------------
- The TRBE devices appear on the existing coresight bus alongside the other
- coresight devices::
- >$ ls /sys/bus/coresight/devices
- trbe0 trbe1 trbe2 trbe3
- The ``trbe<N>`` named TRBEs are associated with a CPU.::
- >$ ls /sys/bus/coresight/devices/trbe0/
- align flag
- *Key file items are:-*
- * ``align``: TRBE write pointer alignment
- * ``flag``: TRBE updates memory with access and dirty flags
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