ARM: Rework how unrecognized/unimplemented instructions are handled.

Instead of panic immediately when these instructions are executed, an
UndefinedInstruction fault is returned. In FS mode (not currently
implemented), this is the fault that should, to my knowledge, be triggered in
these situations and should be handled using the normal architected
mechanisms. In SE mode, the fault causes a panic when it's invoked that gives
the same information as the instruction did. When/if support for speculative
execution of ARM is supported, this will allow a mispeculated and unrecognized
and/or unimplemented instruction from causing a panic. Only once the
instruction is going to be committed will the fault be invoked, triggering the
panic.

1 files changed, 17 insertions, 3 deletions

diff --git a/src/arch/arm/isa/formats/unknown.isa b/src/arch/arm/isa/formats/unknown.isa
index 97a0caa6b..e4bb94899 100644
--- a/src/arch/arm/isa/formats/unknown.isa
+++ b/src/arch/arm/isa/formats/unknown.isa
@@ -1,5 +1,17 @@
 // -*- mode:c++ -*-
 
+// Copyright (c) 2010 ARM Limited
+// All rights reserved
+//
+// The license below extends only to copyright in the software and shall
+// not be construed as granting a license to any other intellectual
+// property including but not limited to intellectual property relating
+// to a hardware implementation of the functionality of the software
+// licensed hereunder.  You may use the software subject to the license
+// terms below provided that you ensure that this notice is replicated
+// unmodified and in its entirety in all distributions of the software,
+// modified or unmodified, in source code or in binary form.
+//
 // Copyright (c) 2007-2008 The Florida State University
 // All rights reserved.
 //
@@ -72,9 +84,11 @@ output exec {{
     Unknown::execute(%(CPU_exec_context)s *xc,
                      Trace::InstRecord *traceData) const
     {
-        panic("attempt to execute unknown instruction "
-              "(inst 0x%08x, opcode 0x%x, binary: %s)", machInst, OPCODE, inst2string(machInst));
-        return new UnimpFault("Unimplemented Instruction");
+#if FULL_SYSTEM
+        return new UndefinedInstruction;
+#else
+        return new UndefinedInstruction(machInst, true);
+#endif
     }
 }};