Update Kelvin simulation/debug doc

Add Kelvin ISS usage

Change-Id: I012808ad08de2cd679e272950894ad8dd7c9b527

KelvinIssDebugging.md

diff --git a/KelvinIssDebugging.md b/KelvinIssDebugging.md
index 14f4603..8266441 100644
--- a/KelvinIssDebugging.md
+++ b/KelvinIssDebugging.md
@@ -8,7 +8,28 @@
 [MPACT_Sim](https://github.com/google/mpact-sim) and supports all the kelvin
 instructions. It is used for single-core testing and debugging.
 
-**TODO** Add kelvin sim CLI instructions when it sits in `sim/kelvin`
+Running the Kelvin SW binary can be done with the following CLIs
+
+```bash
+source build/setup.sh
+m kelvin_sim
+sim_kelvin <elf file path>
+```
+
+The bash function detects the file type by ELF's *magic_bytes* and launches the `kelvin_sim`. `kelvin_sim` runs the exetuable, and depends on the terminator ops
+`mpause` or `ebreak`, it prints out different messages before exit the simulator.
+
+Illegal instruction also terminates the simulation, with the fault PC printed out.
+
+### Debug Kelvin SW via Kelvin Sim
+
+```bash
+sim_kelvin <elf file path> debug
+```
+
+It launches `kelvin_sim` in the interactive mode. It acts as a debugger, with
+`break`, `run`, and `step` available for instructions. Use `help` to see the
+supported debug functions.
 
 ## Running Kelvin ISS with Renode
 
@@ -21,7 +42,7 @@
 
 ```bash
 source build/setup.sh
-
+m renode
 sim_kelvin <location of the kelvin SW .bin file>
 ```