t/to

The t command performs a trace (single step) operation.

Format

The format for this command is:

t [-vbci]
or:

to [-vbci]
where:

-v lists each step (verbose).
-b captures only branches.
-c captures only calls (jal instruction).
-i stops on invalid program counter.
cnt traces cnt instructions.

Functional Description

The t command executes the instruction addressed by the current value of the EPC register. The to command is similar to the t command, except that the to command treats an entire procedure as a single step. For example, if the current instruction at EPC is a jump and link instruction, jal, the next stop is at EPC+8.

A branch instruction and the instruction in its delay slot are executed as a single step. This also means that two-instruction loops are treated as a single step. This command is implemented by setting a breakpoint at the following instruction.

The command or commands that are executed on completion of the single step is determined by the value of the environment variable brkcmd.

An example illustrating the use of this command follows.

	PMON> t 
	Pmon+0x240 3c09a07f lui t1,0xa07f

Files

The t/to commands are located in mon/go.c.


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