diff --git a/X86Disassembler/X86/Handlers/Add/AddEaxImmHandler.cs b/X86Disassembler/X86/Handlers/Add/AddEaxImmHandler.cs
new file mode 100644
index 0000000..2944c7c
--- /dev/null
+++ b/X86Disassembler/X86/Handlers/Add/AddEaxImmHandler.cs
@@ -0,0 +1,57 @@
+namespace X86Disassembler.X86.Handlers.Add;
+
+///
+/// Handler for ADD EAX, imm32 instruction (0x05)
+///
+public class AddEaxImmHandler : InstructionHandler
+{
+ ///
+ /// Initializes a new instance of the AddEaxImmHandler class
+ ///
+ /// The buffer containing the code to decode
+ /// The instruction decoder that owns this handler
+ /// The length of the buffer
+ public AddEaxImmHandler(byte[] codeBuffer, InstructionDecoder decoder, int length)
+ : base(codeBuffer, decoder, length)
+ {
+ }
+
+ ///
+ /// Checks if this handler can decode the given opcode
+ ///
+ /// The opcode to check
+ /// True if this handler can decode the opcode
+ public override bool CanHandle(byte opcode)
+ {
+ return opcode == 0x05;
+ }
+
+ ///
+ /// Decodes an ADD EAX, imm32 instruction
+ ///
+ /// The opcode of the instruction
+ /// The instruction object to populate
+ /// True if the instruction was successfully decoded
+ public override bool Decode(byte opcode, Instruction instruction)
+ {
+ // Set the mnemonic
+ instruction.Mnemonic = "add";
+
+ // Read the immediate value
+ int position = Decoder.GetPosition();
+ if (position + 4 > Length)
+ {
+ // Not enough bytes for the immediate value
+ instruction.Operands = "eax, ??";
+ return true; // Still return true as we've set a valid mnemonic and operands
+ }
+
+ // Read the 32-bit immediate value
+ uint imm32 = Decoder.ReadUInt32();
+
+ // Set the operands
+ instruction.Operands = $"eax, 0x{imm32:X8}";
+
+ return true;
+ }
+}
diff --git a/X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs b/X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs
index 25ddf6e..0424ca2 100644
--- a/X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs
+++ b/X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs
@@ -249,6 +249,7 @@ public class InstructionHandlerFactory
// Add ADD handlers
_handlers.Add(new AddR32Rm32Handler(_codeBuffer, _decoder, _length));
_handlers.Add(new AddRm32R32Handler(_codeBuffer, _decoder, _length));
+ _handlers.Add(new AddEaxImmHandler(_codeBuffer, _decoder, _length));
// Add ADD immediate handlers from ArithmeticImmediate namespace
_handlers.Add(new AddImmToRm8Handler(_codeBuffer, _decoder, _length));
diff --git a/X86DisassemblerTests/AddEaxImmHandlerTests.cs b/X86DisassemblerTests/AddEaxImmHandlerTests.cs
new file mode 100644
index 0000000..009757b
--- /dev/null
+++ b/X86DisassemblerTests/AddEaxImmHandlerTests.cs
@@ -0,0 +1,52 @@
+namespace X86DisassemblerTests;
+
+using System;
+using Xunit;
+using X86Disassembler.X86;
+using X86Disassembler.X86.Handlers.Add;
+
+///
+/// Tests for ADD EAX, imm32 instruction handler
+///
+public class AddEaxImmHandlerTests
+{
+ ///
+ /// Tests the AddEaxImmHandler for decoding ADD EAX, imm32 instruction
+ ///
+ [Fact]
+ public void AddEaxImmHandler_DecodesAddEaxImm32_Correctly()
+ {
+ // Arrange
+ // ADD EAX, 0x12345678 (05 78 56 34 12)
+ byte[] codeBuffer = new byte[] { 0x05, 0x78, 0x56, 0x34, 0x12 };
+ var decoder = new InstructionDecoder(codeBuffer, codeBuffer.Length);
+
+ // Act
+ var instruction = decoder.DecodeInstruction();
+
+ // Assert
+ Assert.NotNull(instruction);
+ Assert.Equal("add", instruction.Mnemonic);
+ Assert.Equal("eax, 0x12345678", instruction.Operands);
+ }
+
+ ///
+ /// Tests the AddEaxImmHandler for handling insufficient bytes
+ ///
+ [Fact]
+ public void AddEaxImmHandler_HandlesInsufficientBytes_Gracefully()
+ {
+ // Arrange
+ // ADD EAX, ?? (05) - missing immediate value
+ byte[] codeBuffer = new byte[] { 0x05 };
+ var decoder = new InstructionDecoder(codeBuffer, codeBuffer.Length);
+
+ // Act
+ var instruction = decoder.DecodeInstruction();
+
+ // Assert
+ Assert.NotNull(instruction);
+ Assert.Equal("add", instruction.Mnemonic);
+ Assert.Equal("eax, ??", instruction.Operands);
+ }
+}