initial implmeentation...

the direction bit is throwing me off vs the order I'm seeing from nasm's syntax.

part_1/meson.build

@@ -1,5 +1,5 @@
-project( 'sim_8086', 'c', 'cpp' )
+project( 'sim_8086', 'c', 'cpp', default_options : ['buildtype=debug'] )
 
 include_thirdparty = include_directories( '../thirdparty' )
 
-executable( 'sim_8086', 'sim_8086.c', include_directories : include_thirdparty )
+executable( 'sim_8086', 'sim_8086.cpp', include_directories : include_thirdparty )

part_1/sim_8086.c

@@ -1,12 +0,0 @@
-#define ZPL_IMPLEMENTATION
-#include "zpl.h"
-
-
-
-
-int main()
-{
-	zpl_printf("sim 8086!");
-
-	return 0;
-}

part_1/sim_8086.cpp

@@ -0,0 +1,647 @@
+#if __clang__
+#pragma clang diagnostic ignored "-Wunused-const-variable"
+#endif
+
+
+#pragma region 							ZPL INCLUDE
+
+#if __clang__
+	#pragma clang diagnostic push 
+	#pragma clang diagnostic ignored "-Wmissing-braces"
+	#pragma clang diagnostic ignored "-Wbraced-scalar-init"
+#endif
+
+#define ZPL_IMPLEMENTATION
+#include "zpl.h"
+
+#if __clang__
+	#pragma clang diagnostic pop
+#endif
+
+#pragma endregion 						ZPL INCLUDE
+
+
+// This has me screwing around with generating lookup tables.
+// Going to measure the difference between them and jump tables instructions at some point...
+
+// Binary formatting for literals is used heavily as that is 
+// how the encoding is conveyed in the hardware reference from intel.
+
+
+#define bit( value ) ( 1 << value )
+#define bitfield_is_equal( field_, mask_ ) ( ( mask_ & field_ ) == mask_ )
+#define ct constexpr
+#define forceinline ZPL_ALWAYS_INLINE
+#define MSG_INVALID_VALUE "INVALID VALUE PROVIDED"
+
+
+using u8  = unsigned char;
+using u16 = unsigned short;
+using u32 = unsigned long;
+
+// using bytecode = u8;
+
+
+inline
+char char_binary( u8 value, u8 pos )
+{
+	constexpr u8 baseline = 1;
+	u8 mask = baseline << pos;
+
+	return ( (baseline << pos) & value) == mask ? '1' : '0';
+}
+
+inline
+void str_binary( char* result, u8 value )
+{
+#if 0
+	result[0] = char_binary( value, 0);
+	result[1] = char_binary( value, 1);
+	result[2] = char_binary( value, 2);
+	result[3] = char_binary( value, 3);
+	result[4] = char_binary( value, 4);
+	result[5] = char_binary( value, 5);
+	result[6] = char_binary( value, 6);
+	result[7] = char_binary( value, 7);
+#else
+	result[0] = char_binary( value, 7);
+	result[1] = char_binary( value, 6);
+	result[2] = char_binary( value, 5);
+	result[3] = char_binary( value, 4);
+	result[4] = char_binary( value, 3);
+	result[5] = char_binary( value, 2);
+	result[6] = char_binary( value, 1);
+	result[7] = char_binary( value, 0);
+#endif
+}
+
+
+#define USE_LOOKUP_TABLE 0
+namespace Op
+{
+	ct u8 Mask = 0b11111100;
+
+	#define D_Opcodes \
+	D_Entry( mov_88 ) \
+	D_Entry( mov_89 ) \
+
+	using Type = u8;
+	enum
+	{
+	#if USE_LOOKUP_TABLE
+		#define D_Entry( Entry_ ) Entry_,
+		D_Opcodes
+		#undef D_Entry
+
+	#else 
+		mov_88 = 0b10001000,
+		mov_89 = 0b11000100,
+
+	#endif
+	
+		Num = 2
+	};
+
+#if USE_LOOKUP_TABLE
+	ct u8 code( Type type ) 
+	{
+		constexpr u8 
+		type_to_code[ Num ] =
+		{
+			0b01000100, // mov_88
+			0b11000100, // mov_89
+		};
+
+		return type_to_code[ type ];
+	}
+
+	ct u8 type( u8 code )
+	{
+		switch ( code )
+		{
+			#define D_Entry
+			case 0b01000100: 
+				return mov_88;
+
+			#undef D_Entry
+		}
+
+		return Num;
+	}
+#endif
+
+	char const* str( Type type )
+	{
+	#if Op_USE_LOOKUP_TABLE
+		static char const* 
+		type_to_str[ Num ] =
+		{
+			#define D_Entry( Entry_ ) #Entry_,
+			D_Opcodes
+			#undef D_Entry
+		};
+
+		return type_to_str[ type ];
+
+	#else
+		switch ( type )
+		{
+			case mov_88:
+				return "mov_88";
+			case mov_89:
+				return "mov_89";
+		}
+
+		return MSG_INVALID_VALUE;
+	#endif
+	}
+
+	ct char const* helper_meumonic( Type type )
+	{
+		switch ( type )
+		{
+			case mov_88:
+			case mov_89:
+				return "mov";
+		}
+
+		return MSG_INVALID_VALUE;
+	}
+
+	char const* meumonic( Type type )
+	{
+	#if USE_LOOKUP_TABLE
+		static char const* 
+		type_to_meumonic[ Num ] = 
+		{
+			#define D_Entry( Entry_ ) helper_meumonic( Entry_ ),
+			D_Opcodes
+			#undef D_Entry
+		};
+
+		return type_to_meumonic[ type ];
+
+	#else
+		switch ( type )
+		{
+			case mov_88:
+			case mov_89:
+				return "mov";
+		}
+
+		return MSG_INVALID_VALUE;
+	#endif
+	}
+
+	ct char const* helper_intuitive( Type type )
+	{
+		switch ( type )
+		{
+			case mov_88:
+			case mov_89:
+				return "move";
+		}
+
+		return MSG_INVALID_VALUE;
+	}
+
+	char const* intuitive( Type type )
+	{
+	#if USE_LOOKUP_TABLE
+		static char const* 
+		type_to_meumonic[ Num ] = 
+		{
+			#define D_Entry( Entry_ ) helper_intuitive( Entry_ ),
+			D_Opcodes
+			#undef D_Entry
+		};
+	
+		return type_to_meumonic[ type ];
+		
+	#else
+
+		switch ( type )
+		{
+			case mov_88:
+			case mov_89:
+				return "move";
+		}
+
+		return MSG_INVALID_VALUE;
+	#endif
+	}
+
+	#undef D_Opcodes
+}
+
+namespace Field
+{
+#if 0
+	using Type = u8;
+	enum
+	{
+		Dir_REG_Dest = 0b00,
+		Dir_REG_Src  = 0b10,
+
+		
+	};
+#endif
+	ct u8 Mask_Dir   = 0b00000010;
+	ct u8 Mask_Width = 0b00000001;
+	ct u8 Mask_Mode  = 0b11000000;
+
+	// Mask: Effective Address
+	inline u8 mask_reg_operand( u8 reg )
+	{
+		return reg << 3;
+	}
+
+	// https://i.imgur.com/drsyYnM.png
+	ct u8 Dir_REG_Src   = 0b00;
+	ct u8 Dir_REG_Dest  = 0b10;
+
+	inline
+	char const* str_direction( u8 direction )
+	{
+		switch ( direction )
+		{
+			case Dir_REG_Dest:
+				return "Destination";
+
+			case Dir_REG_Src:
+				return "Source";
+		}
+
+		return MSG_INVALID_VALUE;
+	}
+
+	// https://i.imgur.com/9Op8Lnd.png
+	ct u8 Width_Byte = 0b00; 
+	ct u8 Width_Word = 0b01;
+
+	inline
+	char const* str_width( u8 width )
+	{
+		switch ( width )
+		{
+			case Width_Byte:
+				return "Byte";
+
+			case Width_Word:
+				return "Word";
+		}
+
+		return MSG_INVALID_VALUE;
+	}
+
+	// https://i.imgur.com/Job2oPd.png
+	ct u8 Mode_Mem   = 0b00000000;
+	ct u8 Mode_Mem8  = 0b01000000;
+	ct u8 Mode_Mem16 = 0b10000000;
+	ct u8 Mode_Reg   = 0b11000000;
+
+	char const* str_mode( u8 mode )
+	{
+		switch (mode)
+		{
+			case Mode_Mem:
+				return "Memory: No Displacement";
+
+			case Mode_Mem8:
+				return "Memory: 8-bit Displacment";
+
+			case Mode_Mem16:
+				return "Memory: 16-bit Displacement";
+
+			case Mode_Reg:
+				return "Register";
+		}
+
+		return MSG_INVALID_VALUE;
+	}
+
+#if 0
+	ct u8 RegMem_AL        = 0b00000000;
+	ct u8 RegMem_AX        = 0b00000000;
+	ct u8 RegMem_BX_SI     = 0b00000000;
+	ct u8 RegMem_BX_SI_D8  = 0b00000000;
+	ct u8 RegMem_BX_SI_D16 = 0b00000000;
+#endif
+}
+
+namespace Register
+{
+	ct u8 Mask_Left  = 0b00111000;
+	ct u8 Mask_Right = 0b00000111;
+
+	#define D_Opcodes \
+	D_Entry( AL ) \
+	D_Entry( CL ) \
+	D_Entry( DL ) \
+	D_Entry( BL ) \
+	D_Entry( AH ) \
+	D_Entry( CH ) \
+	D_Entry( DH ) \
+	D_Entry( BH ) \
+	D_Entry( AX ) \
+	D_Entry( CX ) \
+	D_Entry( DX ) \
+	D_Entry( BX ) \
+	D_Entry( SP ) \
+	D_Entry( BP ) \
+	D_Entry( SI ) \
+	D_Entry( DI ) \
+
+	using Type = u8;
+	enum
+	{
+		// Endianness is prob wrong...
+		AL = 0b000,
+		CL = 0b001,
+		DL = 0b010,
+		BL = 0b011,
+
+		AH = 0b100,
+		CH = 0b101,
+		DH = 0b110,
+		BH = 0b111,
+
+		AX = 0b000,
+		CX = 0b001,
+		DX = 0b010,
+		BX = 0b011,
+
+		SP = 0b100,
+		BP = 0b101,
+		SI = 0b110,
+		DI = 0b111,
+
+		Num = 16
+	};
+
+	char const* meumonic( Type type, u8 Width )
+	{
+		static char const* 
+		Type_To_Meumonic[ Num ] = 
+		{
+			#define D_Entry( Entry_ ) #Entry_,
+			D_Opcodes
+			#undef D_Entry
+		};
+	
+		return Type_To_Meumonic[ type + Width * 7 + 1 ];
+	}
+
+	char const* intuitive( Type type, u8 Width )
+	{
+		static char const* 
+		Type_To_Intuitive[ Num ] = 
+		{
+			"A.Low",
+			"C.Low",
+			"D.Low",
+			"B.Low",
+			"A.High",
+			"C.High",
+			"D.High",
+			"B.High",
+			"A.16",
+			"C.16",
+			"D.16",
+			"B.16",
+			"Stack.Pointer",
+			"Stack.Base",
+			"Source.Index",
+			"Destination.Index",
+		};
+	
+		return Type_To_Intuitive[ type + 8 * Width ];
+	}
+}
+
+// 8086 Instructions are 1 to 6 bytes in length.
+struct POD_Instruction
+{
+	u8 Byte_1;
+	u8 Byte_2;
+	u8 Byte_3;
+	u8 Byte_4;
+	u8 Byte_5;
+	u8 Byte_6;
+
+	u16 Pad;
+};
+
+struct Instruction : public POD_Instruction
+{
+	inline
+	u8 direction()
+	{
+		u8 direction = Byte_1 & Field::Mask_Dir; 
+
+		return direction;
+	}
+
+	inline 
+	u8 mode()
+	{
+		u8 mode = Byte_2 & Field::Mask_Mode;
+
+		return mode;
+	}
+
+	inline
+	u8 opcode()
+	{
+		u8 
+		opcode = Byte_1 & Op::Mask;
+
+		return opcode;
+	}
+
+	inline
+	u8 operand_left()
+	{
+		u8 
+		operand  = Byte_2 & Register::Mask_Left;
+		operand >>= 3;
+
+		return operand;
+	}
+
+	inline
+	u8 operand_right()
+	{
+		u8 
+		operand = Byte_2 & Register::Mask_Right;
+		// operand <<= 1;
+
+		return operand;
+	}
+
+	inline
+	u8 width()
+	{
+		u8 width = Byte_1 & Field::Mask_Width;
+
+		return width;
+	}
+
+	void disassemble()
+	{
+		using namespace Field;
+		using namespace Op;
+		using namespace Register;
+
+		u8 width_val = width();
+
+		char const* opcode_str        = Op::meumonic( opcode() );
+		char const* direction_str     = Field::str_direction( direction() );
+		char const* width_str         = Field::str_width( width_val );
+		char const* mode_str          = Field::str_mode( mode() );
+		char const* operand_left_str  = Register::meumonic( operand_left(), width_val );
+		char const* operand_right_str = Register::meumonic( operand_right(), width_val );
+
+		char
+		binary_string[9];
+		binary_string[8] = '\0';
+
+		str_binary( binary_string, opcode() );
+		zpl_printf("\nOpcode     : %s : %s", binary_string, opcode_str);
+
+		str_binary( binary_string, direction() );
+		zpl_printf("\nDirection  : %s : %s", binary_string, direction_str);
+
+		str_binary( binary_string, width_val );
+		zpl_printf("\nWidth      : %s : %s", binary_string, width_str);
+
+		str_binary( binary_string, mode() );
+		zpl_printf("\nMode       : %s : %s", binary_string, mode_str);
+
+		str_binary( binary_string, operand_left() );
+		zpl_printf("\nOperand    : %s : %s", binary_string, operand_left_str);
+
+		str_binary( binary_string, operand_right() );
+		zpl_printf("\nOperand EA : %s : %s", binary_string, operand_right_str);
+	}
+};
+
+namespace Tests
+{
+	zpl_arena BlobArena {};
+	void Init()
+	{
+		zpl_arena_init_from_allocator( & BlobArena, zpl_heap(), zpl_megabytes(1) );
+
+		if ( BlobArena.total_size == 0 )
+		{
+			zpl_assert_crash( "Failed to reserve memory for Tests:: BLobArena" );
+		}
+	}
+
+	void Try_MockInstruction()
+	{
+		using namespace Field;
+		using namespace Op;
+		using namespace Register;
+
+		Instruction
+		mock; // mov AX, BX
+	#if USE_LOOKUP_TABLE
+		mock.Byte_1 = Op::code(mov_88) | Dir_REG_Dest                | Field::Width_Word;
+	#else
+		mock.Byte_1 = mov_88           | Dir_REG_Src                 | Field::Width_Word;
+	#endif
+		mock.Byte_2 = Field::Mode_Reg  | Field::mask_reg_operand(BX) | CX;
+
+		zpl_printf("\n\nAttempting Mock Instruction: mov CX, BX");
+
+		char
+		binary_string[9];
+		binary_string[8] = '\0';
+
+		str_binary( binary_string, mock.Byte_1 );
+		zpl_printf("\n%s", binary_string);
+
+		str_binary( binary_string, mock.Byte_2 );
+		zpl_printf("\n%s", binary_string);
+
+		mock.disassemble();
+	}
+
+	void Try_Blob_SingleRegisterMove()
+	{
+		zpl_printf("\n\nAttempting to read blob: listing_0037_single_register_mov");
+
+		zpl_file_contents 
+		blob = zpl_file_read_contents( zpl_arena_allocator( & BlobArena), false, 
+		"tests/listing_0037_single_register_mov"
+		// "tests/listing_0038_many_register_mov"
+		);
+
+		if (blob.data == nullptr )
+		{
+			return;
+		}
+
+		printf("\nContents:\n");
+
+		u32 left = blob.size;
+		u8* data = cast(u8*)blob.data 
+		// + blob.size - 1
+		;
+
+		char
+		binary_string[9];
+		binary_string[8] = '\0';
+
+		while ( left-- )
+		{
+			str_binary( binary_string, data[0]);
+
+			printf("%s\n", binary_string );
+
+			data += 1;
+		}
+
+		printf("\n");
+
+		left = blob.size;
+		// data += blob.size;
+		data -= blob.size;
+		while ( left-- )
+		{
+			str_binary( binary_string, data[0]);
+
+			printf("%X", data[0] );
+
+			data += 1;
+		}
+
+		Instruction
+		instr;
+		instr.Byte_1 = ((u8*)blob.data)[0];
+		instr.Byte_2 = ((u8*)blob.data)[1];
+		instr.disassemble();
+	}
+}
+
+
+int main()
+{
+	zpl_printf("sim 8086!");
+
+	Tests::Init();
+	
+	zpl_f64 start = zpl_time_rel();
+
+	Tests::Try_MockInstruction();
+	Tests::Try_Blob_SingleRegisterMove();
+
+	zpl_f64 end = zpl_time_rel();
+
+	printf("\n\nElapsed Time: %lf", end - start);
+	printf("\n\n");
+
+	return 0;
+}

part_1/tests/listing_0037_single_register_mov

@@ -0,0 +1 @@
+菓

part_1/tests/listing_0038_many_register_mov

@@ -0,0 +1 @@
+‰Ùˆå‰Ú‰Þ‰ûˆÈˆí‰Ã‰ó‰ü‰Å