1Activity Monitors 2================= 3 4FEAT_AMUv1 of the Armv8-A architecture introduces the Activity Monitors 5extension. This extension describes the architecture for the Activity Monitor 6Unit (|AMU|), an optional non-invasive component for monitoring core events 7through a set of 64-bit counters. 8 9When the ``ENABLE_AMU=1`` build option is provided, Trusted Firmware-A sets up 10the |AMU| prior to its exit from EL3, and will save and restore architected 11|AMU| counters as necessary upon suspend and resume. 12 13-------------- 14 15*Copyright (c) 2021, Arm Limited. All rights reserved.* 16