code: /*
   * Copyright (c) 2014, Aleksander Osman
   * All rights reserved.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   * 
   * * Redistributions of source code must retain the above copyright notice, this
   *   list of conditions and the following disclaimer.
   * 
   * * Redistributions in binary form must reproduce the above copyright notice,
   *   this list of conditions and the following disclaimer in the documentation
   *   and/or other materials provided with the distribution.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package ao486.test.branch;
  
  import ao486.test.TestUnit;
  import ao486.test.layers.EffectiveAddressLayerFactory;
  import ao486.test.layers.FlagsLayer;
  import ao486.test.layers.GeneralRegisterLayer;
  import ao486.test.layers.HandleModeChangeLayer;
  import ao486.test.layers.IOLayer;
  import ao486.test.layers.InstructionLayer;
  import ao486.test.layers.Layer;
  import ao486.test.layers.MemoryLayer;
  import ao486.test.layers.MemoryPatchLayer;
  import ao486.test.layers.OtherLayer;
  import ao486.test.layers.Pair;
  import ao486.test.layers.SegmentLayer;
  import ao486.test.layers.StackLayer;
  import java.io.*;
  import java.util.LinkedList;
  import java.util.Random;
  
  
  public class TestJMP_real_v8086 extends TestUnit implements Serializable {
      public static void main(String args[]) throws Exception {
          run_test(TestJMP_real_v8086.class);
      }
      
      //--------------------------------------------------------------------------
      @Override
      public int get_test_count() throws Exception {
          return 100;
      }
      
      @Override
      public void init() throws Exception {
          
          random = new Random(3 + index);
          
          String instruction;
          while(true) {
              layers.clear();
              
              LinkedList<Pair<Long, Long>> prohibited_list = new LinkedList<>();
              
              // if false: v8086 mode
              boolean is_real = random.nextBoolean();
              
              InstructionLayer instr  = new InstructionLayer(random, prohibited_list);
              layers.add(instr);
              StackLayer stack        = new StackLayer(random, prohibited_list);
              layers.add(stack);
              layers.add(new OtherLayer(is_real ? OtherLayer.Type.REAL : OtherLayer.Type.PROTECTED_OR_V8086, random));
              layers.add(new FlagsLayer(is_real ? FlagsLayer.Type.RANDOM : FlagsLayer.Type.V8086, random));
              layers.add(new GeneralRegisterLayer(random));
              layers.add(new SegmentLayer(random));
              layers.add(new MemoryLayer(random));
              layers.add(new IOLayer(random));
              layers.addFirst(new HandleModeChangeLayer(
                      getInput("cr0_pe"),
                      getInput("vmflag"),
                      getInput("cs_rpl"),
                      getInput("cs_p"),
                      getInput("cs_s"),
                      getInput("cs_type")
              ));
              
              /*
               * 0 - eip out of bounds
               * 
               * 1 - all ok
               */
              
              int type = random.nextInt(2);
              
              // instruction size
              boolean cs_d_b = getInput("cs_d_b") == 1;
              
              boolean a32 = random.nextBoolean();
              boolean o32 = random.nextBoolean();
              
              // destination
              long cs         = random.nextInt(0xFFFF+1);
              long cs_limit   = (is_real == false)? 0xFFFF : getInput("cs_limit");
              long new_eip    = random.nextInt((int)cs_limit+1);
              
              if(o32 == false) new_eip &= 0xFFFF;
              
              if(type == 0 && o32 == false && cs_limit <= 0xFFFF) new_eip = 0xFFFF - 4 + random.nextInt(5);
              if(type == 0 && o32 == true)                        new_eip = cs_limit + random.nextInt(5);
              
              // dest instruction
              long dest = (cs << 4) + new_eip;
  
              boolean can_add = Layer.collides(prohibited_list, (int)dest, (int)(dest+1));
              if(can_add == false) continue;
              
              MemoryPatchLayer patch = new MemoryPatchLayer(random, prohibited_list, (int)dest, 0x0F,0x0F);
              layers.addFirst(patch);
              
              // add instruction
              byte extra_bytes[] = null;
              
              boolean is_Ep = random.nextBoolean();
              
              if(is_Ep) {
                  byte modregrm_bytes[] = EffectiveAddressLayerFactory.prepare(
                          o32? (((cs & 0xFFFF) << 32) | (new_eip & 0xFFFFFFFF)) : (((cs & 0xFFFF) << 16) | (new_eip & 0xFFFF)),
                          5, EffectiveAddressLayerFactory.modregrm_reg_t.SET,
                          o32? 6 : 4, a32,
                          layers, random, this, true, false);
                  extra_bytes = modregrm_bytes;
              }
              else {
                  long immediate = o32? (((cs & 0xFFFF) << 32) | (new_eip & 0xFFFFFFFF)) : (((cs & 0xFFFF) << 16) | (new_eip & 0xFFFF));
              
                  byte imm_bytes[] = new byte[o32? 6 : 4];
                  for(int i=0; i<imm_bytes.length; i++) {
                      imm_bytes[i] = (byte)(immediate & 0xFF);
                      immediate >>= 8;
                  }
                  extra_bytes = imm_bytes;
              }
              
              instruction = prepare_instr(cs_d_b, a32, o32, extra_bytes, is_Ep);
              instr.add_instruction(instruction);
  
  System.out.printf("a32: %b, o32: %b, cs_d_b: %b\n", a32,o32,cs_d_b);
  System.out.printf("cs: %x\n", cs);
  System.out.printf("cs_limit: %x\n", cs_limit);
  System.out.printf("new_eip: %x\n", new_eip);
  System.out.printf("o32: %b\n", o32);
  System.out.printf("is_real: %b\n", is_real);
  
              // end condition
              break;
          }
          
          System.out.println("Instruction: [" + instruction + "]");
      }
  
      String prepare_instr(boolean cs_d_b, boolean a32, boolean o32, byte extra_bytes[], boolean is_Ep) throws Exception {
          int opcodes[] = {
              0xFF, 0xEA
          };
          
          String prefix = "";
          if(cs_d_b != o32) { prefix = "66" + prefix; }
          if(cs_d_b != a32) { prefix = "67" + prefix; }
          
          int opcode = opcodes[is_Ep? 0 : 1];
          
          byte instr[] = new byte[1 + extra_bytes.length];
          instr[0] = (byte)opcode;
          System.arraycopy(extra_bytes, 0, instr, 1, extra_bytes.length);
          
          return prefix + bytesToHex(instr);
      }
  
  }