0x80: Trap::shutdown({{fault = new IllegalInstruction;}});
                  0x81: FailUnimpl::siam();
              }
 +#if FULL_SYSTEM
              // M5 special opcodes use the reserved IMPDEP2A opcode space
              0x37: decode M5FUNC {
+ #if FULL_SYSTEM
                  // we have 7 bits of space here to play with...
                  0x21: m5exit({{PseudoInst::m5exit(xc->tcBase(), O0);
                                }}, No_OpClass, IsNonSpeculative);
                  0x54: m5panic({{
                                panic("M5 panic instruction called at pc=%#x.", xc->readPC());
                                }}, No_OpClass, IsNonSpeculative);
- 
+ #endif
+                 default: Trap::impdep2({{fault = new IllegalInstruction;}});
              }
 +#else
 +            0x37: Trap::impdep2({{fault = new IllegalInstruction;}});
 +#endif
              0x38: Branch::jmpl({{
                  Addr target = Rs1 + Rs2_or_imm13;
                  if(target & 0x3)