From d4ec188ef1d6bae7fe56075712009bbc2088e446 Mon Sep 17 00:00:00 2001
From: tuz358 <orca00358@gmail.com>
Date: Mon, 5 Mar 2018 08:34:42 +0900
Subject: [PATCH] Add add_rm32_r32(0x01) instruction

---
 include/instructions.h |  1 +
 instructions.cpp       | 51 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/include/instructions.h b/include/instructions.h
index 2510334..2373cc4 100644
--- a/include/instructions.h
+++ b/include/instructions.h
@@ -23,6 +23,7 @@ public:
   void calc_modrm();
   void execute_opcode(uint8_t opcode);
 
+  void add_rm32_r32();  // 0x01
   void xor_rm32_r32();  // 0x31
   void mov_rm32_r32();  // 0x89
   void nop();           // 0x90
diff --git a/instructions.cpp b/instructions.cpp
index ce9ba1f..511be6d 100644
--- a/instructions.cpp
+++ b/instructions.cpp
@@ -20,6 +20,7 @@ void Instructions::init(uint32_t eip, uint32_t esp, Memory memory){
 void Instructions::init_instructions(){
   memset(this->instructions, 0, sizeof(this->instructions));
 
+  this->instructions[0x01] = &Instructions::add_rm32_r32;
   this->instructions[0x31] = &Instructions::xor_rm32_r32;
   this->instructions[0x89] = &Instructions::mov_rm32_r32;
   this->instructions[0x90] = &Instructions::nop;
@@ -46,6 +47,56 @@ void Instructions::execute_opcode(uint8_t opcode){
   (this->*instructions[opcode])();
 }
 
+void Instructions::add_rm32_r32(){
+  printf("add_rm32_r32 called.\n");
+  uint32_t addr, dst, imm32;
+  uint8_t imm8;
+
+  this->modrm = memory.read_uint8(this->eip);
+  this->calc_modrm();
+
+  switch (this->mod) {
+    case 0:
+      // add [M], R
+      // addr : M
+      this->eip++;
+      addr = this->registers[this->M];
+      // dst : data of [M]
+      dst = memory.read_uint32(addr);
+      memory.write_uint32(addr, dst + this->registers[this->R]);
+      break;
+    case 1:
+      // add [M+imm8], R
+      this->eip++;
+      imm8 = memory.read_uint8(this->eip);
+      // addr : M
+      addr = this->registers[this->M];
+      // dst : data of [M+imm8]
+      dst = memory.read_uint32(addr + imm8);
+      memory.write_uint32(addr + imm8, dst + this->registers[this->R]);
+      this->eip++;
+      break;
+    case 2:
+      // add [M+imm32], R
+      this->eip++;
+      imm32 = memory.read_uint32(this->eip);
+      imm32 = swap_endian32(imm32);
+      // addr : M
+      addr = this->registers[this->M];
+      // dst : data of [M+imm32]
+      dst = memory.read_uint32(addr + imm32); // error
+      memory.write_uint32(addr, dst + this->registers[this->R]);
+      this->eip += 4;
+      break;
+    default:
+      // case mod == 3
+      // add M, R
+      this->eip++;
+      this->registers[this->M] += this->registers[this->R];
+      break;
+  }
+}
+
 void Instructions::xor_rm32_r32(){
   printf("xor_rm32_r32 called.\n");
   uint32_t addr, dst, imm32;