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get cycle counts after reset for a53 processor

WatterCutter

noticed that there is a signal for generic timer called:

CNTVALUEB[63:0] Input Global system counter value in binary format

in  Cortex®-A53 MPCore Processor Revision: r0p4 Technical Reference Manual A.6 

how to get the value?

since I wanna the cycle counts after reset of processor, not the periodic counts after reset of PMCCNTR_EL0.

thanks.

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    Note, the Global Count (what's signalled by CNTVALUEB) is not a cycle count.  The Global System Count is a fixed frequency count, usually incrementing in the low MHz or in newer systems at 1GHz, used to track the progress of time. To get the current System Count, you can read CNTPCT_EL0.  You can learn more about the System Count and Generic Timers here: Documentation – Arm Developer 

    If what you want is a cycles (which aren't necessarily fixed frequency), then try using PMCCNTR_EL0 

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    Note, the Global Count (what's signalled by CNTVALUEB) is not a cycle count.  The Global System Count is a fixed frequency count, usually incrementing in the low MHz or in newer systems at 1GHz, used to track the progress of time. To get the current System Count, you can read CNTPCT_EL0.  You can learn more about the System Count and Generic Timers here: Documentation – Arm Developer 

    If what you want is a cycles (which aren't necessarily fixed frequency), then try using PMCCNTR_EL0 

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