Add mkdir Support

Added missing instructions for mkdir.

Author: ykskb

emulator_functions.c

@@ -475,6 +475,16 @@ void update_eflags_add_8bit(Emulator *emu, uint8_t value1, uint8_t value2, uint1
     set_sign_flag(emu, signr);
 }
 
+void update_eflags_add_16bit(Emulator *emu, uint8_t value1, uint8_t value2, uint16_t result)
+{
+    int sign1 = value1 >> 15;
+    int sign2 = value2 >> 15;
+    int signr = (result >> 15) & 1;
+    set_carry_flag(emu, result >> 16);
+    set_overflow_flag(emu, sign1 == sign2 && sign1 != signr);
+    set_sign_flag(emu, signr);
+}
+
 /* 
  * 1000 (-8) - 0001 (1) = 10111 (-9) -> carry
  * 1000 (-8) - 0010 (2) = 10110 (-10) -> carry

emulator_functions.h

@@ -96,6 +96,7 @@ int32_t is_overflow(Emulator *emu);
 
 void update_eflags_add(Emulator *emu, uint32_t value1, uint32_t value2, uint64_t result);
 void update_eflags_add_8bit(Emulator *emu, uint8_t value1, uint8_t value2, uint16_t result);
+void update_eflags_add_16bit(Emulator *emu, uint8_t value1, uint8_t value2, uint16_t result);
 
 void update_eflags_sub(Emulator *emu, uint32_t value1, uint32_t value2, uint64_t result);
 void update_eflags_sub_8bit(Emulator *emu, uint8_t value1, uint8_t value2, uint16_t result);

instruction_defs.h

@@ -177,7 +177,7 @@ void code_d0(Emulator *emu);
 void code_d1(Emulator *emu);
 void code_d2(Emulator *emu);
 void code_d3(Emulator *emu);
-void set_al_on_c(Emulator *emu);
+void set_al_on_carry(Emulator *emu);
 
 /* 0xE0 */
 void loopnz(Emulator *emu);

instructions.c

@@ -402,6 +402,12 @@ void init_instructions(void)
     instructions[0xCD] = int_imm8;
     instructions[0xCF] = iret;
 
+    instructions[0xD0] = code_d0;
+    instructions[0xD1] = code_d1;
+    instructions[0xD2] = code_d2;
+    instructions[0xD3] = code_d3;
+    instructions[0xD6] = set_al_on_carry;
+
     instructions[0xE0] = loopnz;
     instructions[0xE1] = loopz;
     instructions[0xE2] = loop;

instructions_80.c

@@ -559,6 +559,24 @@ void code_83(Emulator *emu)
     }
 }
 
+/*
+ * add rm16 imm8: 3|4 bytes
+ * Adds imm8 to RM16. Op code 83 and ModR/M op code: 0 execute this.
+ * 1 byte: shared op (83)
+ * 1|2 byte: ModR/M
+ * 1 byte: imm8 to add
+ */
+static void add_rm16_imm8(Emulator *emu, ModRM *modrm)
+{
+    uint16_t rm16 = get_rm16(emu, modrm);
+    uint16_t imm8 = (uint16_t)get_sign_code8(emu, 0);
+    emu->eip += 1;
+
+    uint32_t result = (uint32_t)rm16 + (uint32_t)imm8;
+    set_rm16(emu, modrm, result);
+    update_eflags_add_16bit(emu, rm16, imm8, result);
+}
+
 /*
  * cmp rm16 imm8: 3 bytes
  * Compares rm16 value and imm8 value by subtracting in order.
@@ -586,9 +604,9 @@ void code_83_rm16(Emulator *emu)
 
     switch (modrm.opcode)
     {
-    // case 0:
-    //     add_rm16_imm8(emu, &modrm);
-    //     break;
+    case 0:
+        add_rm16_imm8(emu, &modrm);
+        break;
     // case 1:
     //     or_rm16_imm8(emu, &modrm);
     //     break;

instructions_D0.c

@@ -271,7 +271,12 @@ void code_d3(Emulator *emu)
     }
 }
 
-void set_al_on_c(Emulator *emu)
+/*
+ * salc
+ * Sets AL if carry.
+ * 1 byte: op (D6)
+ */
+void set_al_on_carry(Emulator *emu)
 {
     if (is_carry(emu))
     {
@@ -281,4 +286,5 @@ void set_al_on_c(Emulator *emu)
     {
         set_register8(emu, AL, 0x0);
     }
+    emu->eip += 1;
 }