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authorKartik Agaram <vc@akkartik.com>2020-09-07 16:11:26 -0700
committerKartik Agaram <vc@akkartik.com>2020-09-07 16:11:26 -0700
commit31aa22c18825ac01f61e9d7f190564f643a34c33 (patch)
tree44ba9a57764048915bafcd798cc2f788df6754d4 /archive/1.vm/tangle.mu
parentb43268969064760e7c6d7c58809bc55df0388917 (diff)
downloadmu-31aa22c18825ac01f61e9d7f190564f643a34c33.tar.gz
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Diffstat (limited to 'archive/1.vm/tangle.mu')
0 files changed, 0 insertions, 0 deletions
 

generated by cgit-pink 1.4.1-2-gfad0 (git 2.36.2.497.gbbea4dcf42) at 2024-12-27 17:58:43 +0000


 


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//:: call

:(before "End Initialize Op Names")
put_new(Name, "e8", "call disp32 (call)");

:(code)
void test_call_disp32() {
  Mem.push_back(vma(0xbd000000));  // manually allocate memory
  Reg[ESP].u = 0xbd000064;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  e8                                 a0 00 00 00 \n"  // call function offset at 0x000000a0
      // next EIP is 6
  );
  CHECK_TRACE_CONTENTS(
      "run: call imm32 0x000000a0\n"
      "run: decrementing ESP to 0xbd000060\n"
      "run: pushing value 0x00000006\n"
      "run: jumping to 0x000000a6\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0xe8: {  // call disp32 relative to next EIP
  const int32_t offset = next32();
  ++Callstack_depth;
  trace(Callstack_depth+1, "run") << "call imm32 0x" << HEXWORD << offset << end();
//?   cerr << "push: EIP: " << EIP << " => " << Reg[ESP].u << '\n';
  push(EIP);
  EIP += offset;
  trace(Callstack_depth+1, "run") << "jumping to 0x" << HEXWORD << EIP << end();
  break;
}

//:

:(code)
void test_call_r32() {
  Mem.push_back(vma(0xbd000000));  // manually allocate memory
  Reg[ESP].u = 0xbd000064;
  Reg[EBX].u = 0x000000a0;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  ff     d3                                      \n"  // call function offset at EBX
      // next EIP is 3
  );
  CHECK_TRACE_CONTENTS(
      "run: call to r/m32\n"
      "run: r/m32 is EBX\n"
      "run: decrementing ESP to 0xbd000060\n"
      "run: pushing value 0x00000003\n"
      "run: jumping to 0x000000a3\n"
  );
}

:(before "End Op ff Subops")
case 2: {  // call function pointer at r/m32
  trace(Callstack_depth+1, "run") << "call to r/m32" << end();
  const int32_t* offset = effective_address(modrm);
  push(EIP);
  EIP += *offset;
  trace(Callstack_depth+1, "run") << "jumping to 0x" << HEXWORD << EIP << end();
  ++Callstack_depth;
  break;
}

:(code)
void test_call_mem_at_r32() {
  Mem.push_back(vma(0xbd000000));  // manually allocate memory
  Reg[ESP].u = 0xbd000064;
  Reg[EBX].u = 0x2000;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  ff     13                                      \n"  // call function offset at *EBX
      // next EIP is 3
      "== data 0x2000\n"
      "a0 00 00 00\n"  // 0x000000a0
  );
  CHECK_TRACE_CONTENTS(
      "run: call to r/m32\n"
      "run: effective address is 0x00002000 (EBX)\n"
      "run: decrementing ESP to 0xbd000060\n"
      "run: pushing value 0x00000003\n"
      "run: jumping to 0x000000a3\n"
  );
}

//:: ret

:(before "End Initialize Op Names")
put_new(Name, "c3", "return from most recent unfinished call (ret)");

:(code)
void test_ret() {
  Mem.push_back(vma(0xbd000000));  // manually allocate memory
  Reg[ESP].u = 0xbd000064;
  write_mem_u32(Reg[ESP].u, 0x10);
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  c3                                           \n"  // return
      "== data 0x2000\n"
      "10 00 00 00\n"  // 0x00000010
  );
  CHECK_TRACE_CONTENTS(
      "run: return\n"
      "run: popping value 0x00000010\n"
      "run: jumping to 0x00000010\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0xc3: {  // return from a call
  trace(Callstack_depth+1, "run") << "return" << end();
  --Callstack_depth;
  EIP = pop();
  trace(Callstack_depth+1, "run") << "jumping to 0x" << HEXWORD << EIP << end();
  break;
}