Use a breakpoint instruction for a stop message on arm instead of

runtime/vm/constants_arm.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_CONSTANTS_ARM_H_
 #define VM_CONSTANTS_ARM_H_
 
 #include "platform/globals.h"
 #include "platform/assert.h"
 
@@ skipping 321 matching lines @@
 enum Shift {
   kNoShift = -1,
   LSL = 0,  // Logical shift left
   LSR = 1,  // Logical shift right
   ASR = 2,  // Arithmetic shift right
   ROR = 3,  // Rotate right
   kMaxShift = 4
 };
 
 
-// Special Supervisor Call 24-bit codes used in the presence of the ARM
-// simulator for redirection, breakpoints, and stop messages.
-// See /usr/include/asm/unistd.h
-const uint32_t kRedirectionSvcCode = 0x90001f;  //  unused syscall, was sys_stty
-const uint32_t kBreakpointSvcCode = 0x900020;  // unused syscall, was sys_gtty
-const uint32_t kStopMessageSvcCode = 0x9f0001;  // __ARM_NR_breakpoint
-
 // Constants used for the decoding or encoding of the individual fields of
 // instructions. Based on the "Figure 3-1 ARM instruction set summary".
 enum InstructionFields {
   kConditionShift = 28,
   kConditionBits = 4,
   kTypeShift = 25,
   kTypeBits = 3,
   kLinkShift = 24,
   kLinkBits = 1,
   kUShift = 23,
@@ skipping 81 matching lines @@
  public:
   enum {
     kInstrSize = 4,
     kInstrSizeLog2 = 2,
     kPCReadOffset = 8
   };
 
   static const int32_t kNopInstruction =  // nop
       ((AL << kConditionShift) | (0x32 << 20) | (0xf << 12));
 
+  static const int32_t kBreakPointCode = 0xdeb0;  // For breakpoint.
+  static const int32_t kStopMessageCode = 0xdeb1;  // For Stop(message).
+  static const int32_t kSimulatorBreakCode = 0xdeb2;  // For breakpoint in sim.
+  static const int32_t kSimulatorRedirectCode = 0xca11;  // For redirection.
+
   // Breakpoint instruction filling assembler code buffers in debug mode.
   static const int32_t kBreakPointInstruction =  // bkpt(0xdeb0)
       ((AL << kConditionShift) | (0x12 << 20) | (0xdeb << 8) | (0x7 << 4));
 
   // Breakpoint instruction used by the simulator.
   // Should be distinct from kBreakPointInstruction and from a typical user
   // breakpoint inserted in generated code for debugging, e.g. bkpt(0).
   static const int32_t kSimulatorBreakpointInstruction =
       // svc #kBreakpointSvcCode
-      ((AL << kConditionShift) | (0xf << 24) | kBreakpointSvcCode);
+      ((AL << kConditionShift) | (0xf << 24) | kSimulatorBreakCode);
 
   // Runtime call redirection instruction used by the simulator.
   static const int32_t kSimulatorRedirectInstruction =
-      ((AL << kConditionShift) | (0xf << 24) | kRedirectionSvcCode);
+      ((AL << kConditionShift) | (0xf << 24) | kSimulatorRedirectCode);
 
   // Get the raw instruction bits.
   inline int32_t InstructionBits() const {
     return *reinterpret_cast<const int32_t*>(this);
   }
 
   // Set the raw instruction bits to value.
   inline void SetInstructionBits(int32_t value) {
     *reinterpret_cast<int32_t*>(this) = value;
   }
@@ skipping 232 matching lines @@
   static Instr* At(uword pc) { return reinterpret_cast<Instr*>(pc); }
 
  private:
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(Instr);
 };
 
 }  // namespace dart
 
 #endif  // VM_CONSTANTS_ARM_H_