Hi,
We have an ARM v8 based SOC that has got Marvell's ARM trace implementation, with the Trace formatter disabled. ie. FFSR[FtNotPresent] in ETR register space reports 0b1.
Have couple of queries related to the tracing and decoding of this hardware configuration.
1. Does openCSD tool supports decoding of trace capture from hardware that has trace formatter disabled.
From the openCSD RRADME,
"The library will decode formatted trace in three stages:
Frame Deformatting : Removal CoreSight frame formatting from individual trace streams. Packet Processing : Separate individual trace streams into discrete packets. Packet Decode : Convert the packets into fully decoded trace describing the program flow on a core."
So, is it possible for openCSD to carry out decoding bypassing the first stage mentioned above.
2. Linux Coresight ETR driver as part of managing the trace buffer wrap condition, a barrier packet is written at the beginning which is essentially a Frame synchronization packet. This gives an impression that that ETR driver is making an assumption that the trace formatter is implemented in hardware. Should we not need a fix here, to accommodate hardware configurations that doesn't support trace formatter as well ?
Thanks. Linu Cherian