__mst built-in variable

__mst is a special built-in variable in which you can access hardware register content of the current thread. This built-in variable cannot be used in the systrace, BEGIN, and END probes. Also, this built-in variable can be used in the interval probes only if PID is mentioned. The information can be accessed using the -> operator on the __ublock built-in. The registers that can be accessed follow:

r1-r10

General purpose register r1 to r10

r14-r31

General purpose register r14 to r31

iar

Instruction address register

lr

Link register

isisr

Set if in interrupt or exception context.

Usage Example

__mst->lr