How to use trace action in RISC-V target triggers?

[Alan-19950616]

In the current OpenOCD code, the trace related action is not used.

/*
 * trace on:
 */
#define CSR_MCONTROL_ACTION_TRACE_ON        2
/*
 * trace off:
 */
#define CSR_MCONTROL_ACTION_TRACE_OFF       3

[JanMatCodasip]

Hi @Alan-19950616,

In riscv-openocd, there are currently no commands that would set up triggers with trace actions for you.

Still, you can set up such a trigger manually:

1. Reserve the trigger to prevent OpenOCD from touching it - command riscv reserve_trigger
2. Use standard CSR register write commands to set up your trigger: reg tselect <value>, reg tdata1 <value>, ...

[aap-sc]

@Alan-19950616 also see here: #1158

[Alan-19950616]

@JanMatCodasip @aap-sc Thanks for your replies.

The method you propose does successfully configure TRACE_ON/TRACE_OFF, but OpenOCD does not know that these Triggers are being used as TRACE_ON/TRACE_OFF functions, and therefore will conflict with normal hardware breakpoints.

[aap-sc]

@Alan-19950616 have you tried `riscv reserve_trigger mentioned by @JanMatCodasip ? That command is designed to address this issue.

[Alan-19950616]

Thanks. I will close this.