Add simics breakpoint for exceptions

Created a new magic instruction handler that can be enabled via
environment variable to stop the simulation for Hostboot
exceptions.  This is useful when we want to get a backtrace at
the failing spot without recompiling code or having to manually
insert breakpoints in simics directly.

Enable the function by setting HB_BREAK_ON_ERROR
The trigger call is MAGIC_BREAK_ON_ERROR

Change-Id: I17e008281d010e3f8c5e5817e5f30fd0ccb624d0
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/24600
Tested-by: Jenkins Server
Tested-by: FSP CI Jenkins
Reviewed-by: William G. Hoffa <wghoffa@us.ibm.com>
Reviewed-by: Marshall J. Wilks <mjwilks@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/src/build/debug/simics-debug-framework.py b/src/build/debug/simics-debug-framework.py
index 48a8d4818..cae13c134 100755
--- a/src/build/debug/simics-debug-framework.py
+++ b/src/build/debug/simics-debug-framework.py
@@ -485,9 +485,6 @@ except:
 # See src/include/arch/ppc.H for the definitions of the magic args.
 # Hostboot magic args should range 7000..7999.
 def magic_instruction_callback(user_arg, cpu, arg):
-    if arg == 7008:
-        cpu.r3 = random.randint(1, 0xffffffffffffffffL)
-
     if arg == 7006:   # MAGIC_SHUTDOWN
         # KernelMisc::shutdown()
         print "KernelMisc::shutdown() called."
@@ -499,6 +496,9 @@ def magic_instruction_callback(user_arg, cpu, arg):
         # Stop the simulation, much like a hard-coded breakpoint
         SIM_break_simulation( "Simulation stopped. (hap 7007)"  )
 
+    if arg == 7008:
+        cpu.r3 = random.randint(1, 0xffffffffffffffffL)
+
     if arg == 7009:   # MAGIC_MEMORYLEAK_FUNCTION
         magic_memoryleak_function(cpu)
 
@@ -552,6 +552,11 @@ def magic_instruction_callback(user_arg, cpu, arg):
         enableCore1 = "%s; %s; %s; %s"%(enable4,enable5,enable6,enable7)
         SIM_run_alone(run_command, enableCore1 )
 
+    if arg == 7018:   # MAGIC_BREAK_ON_ERROR
+        # Stop the simulation if an env var is set
+        if( os.environ.has_key('HB_BREAK_ON_ERROR') ):
+            SIM_break_simulation( "Stopping sim on HB error. (hap 7018)"  )
+
     if arg == 7055:   # MAGIC_CONTINUOUS_TRACE
         hb_tracBinaryBuffer = cpu.r4
         hb_tracBinaryBufferSz = cpu.r5