assembly/disassembly stuff

source/app.d

@@ -346,12 +346,181 @@ struct PixelBuffer {
 
 } // PixelBuffer
 
+struct Assembler {
+
+	enum OpCode {
+
+		CLS, // CLS
+
+		RET, // RET
+		CALL, // CALL addr
+
+		ADD, // ADD Vx, Vy
+			 // ADD Vx, byte
+			 // ADD I, Vx
+		SUB, // SUB Vx, Vy
+			 // SUB Vx, byte
+		SUBN, // SUBN Vx, Vy
+
+		SE, // SE Vx, Vy
+			// SE Vx, byte
+		SNE, // SNE Vx, byte
+		SKP, // SKP Vx
+		SKNP, // SKNP Vx
+
+		SHL, // SHL Vx {, Vy}
+		SHR, // SHR Vx {, Vy}
+		XOR, // XOR Vx, Vy
+		AND, // AND Vx, Vy
+		OR, // OR Vx, Vy
+
+		LD, // LD Vx, DT
+			// LD DT, Vx
+			// LD ST, Vx
+			// LD Vx, K
+			// LD [I], Vx
+			// LD Vx, [I]
+		
+		RND // RND Vx, byte
+		
+	}
+
+	enum Parameter {
+
+		Vx,
+		Vy,
+
+		DT,
+		ST,
+		K,
+		
+		addr,
+		val
+		
+	}
+
+	struct Instruction {
+
+	}
+
+	import std.array;
+
+	Appender!string dissassembly_data;
+
+	void assemble(const char* input) {
+
+	} // assemble
+
+	void assemble(const char[] input) {
+
+	} // assemble
+
+	const (char)[] disassemble(ubyte[] instructions) {
+
+		import std.range : chunks;
+
+		foreach (ref ubyte[] i; instructions.chunks(2)) {
+
+			ushort opcode = (*(cast(ushort*)(i.ptr)));
+
+			switch (opcode & 0xF000) {
+				case 0x0000:
+					switch (opcode & 0x0FFF) {
+						case 0x00E0: // 0x00E0 Clears the screen.
+
+						case 0x00EE: // 0x00EE Returns from a subroutine.
+						default: // 0x0NNN Calls RCA 1802 program at address NNN. Not necessary for most ROMs.
+							//assert(0, "0x0NNN RCA 1802 program opcode not implemented!");
+							break;
+					}
+					break;
+				case 0x1000: // 0x1NNN Jumps to address NNN.
+				case 0x2000: // 0x2NNN Calls subroutine at NNN.
+				case 0x3000: // 0x3XNN Skips the next instruction if VX equals NN.
+				case 0x4000: // 0x4XNN Skips the next instruction if VX doesn't equal NN.
+				case 0x5000: // 0x5XYO Skips the next instruction if VX equals VY.
+				case 0x6000: // 0x6XNN Sets VX to NN.
+				case 0x7000: // 0x7XNN Adds NN to VX.
+				case 0x8000:
+					switch (opcode) {
+
+						case 0x0000: // 0x8XY0 Sets VX to the value of VY.
+						case 0x0001: // 0x8XY1 Sets VX to VX or VY.
+						case 0x0002: // 0x8XY2	Sets VX to VX and VY.
+						case 0x0003: // 0x8XY3 Sets VX to VX xor VY.
+						case 0x0004: // 0x8XY4 Adds VY to VX. VF is set to 1 when there's a carry, and to 0 when there isn't.
+						case 0x0005: // 0x8XY5 VY is subtracted from VX. VF is set to 0 when there's a borrow, and 1 when there isn't.
+						case 0x0006: // 0x8XY6 Shifts VX right by one. VF is set to the value of the least significant bit of VX before the shift.
+						case 0x0007: // 0x8XY7 Sets VX to VY minus VX. VF is set to 0 when there's a borrow, and 1 when there isn't.
+						case 0x000E: // 0x8XYE Shifts VX left by one. VF is set to the value of the most significant bit of VX before the shift.
+						default: // unhandled for some reason
+							writefln("unknown opcode: 0x%x", opcode);
+							break;
+
+					}
+
+					break;
+
+				case 0x9000: // 0x9XYO Skips the next instruction if VX doesn't equal VY.
+				case 0xA000: // 0xANNN  Sets I to the address NNN.
+				case 0xB000: // 0xBNNN Jumps to the address NNN plus V0.
+				case 0xC000: // 0xCXNN Sets VX to the result of a bitwise and operation on a random number and NN.
+
+				// 0xDXYN
+				// Sprites stored in memory at location in index register (I), 8bits wide.
+				// Wraps around the screen. If when drawn, clears a pixel, register VF is set to 1 otherwise it is zero.
+				// All drawing is XOR drawing (i.e. it toggles the screen pixels).
+				// Sprites are drawn starting at position VX, VY. N is the number of 8bit rows that need to be drawn.
+				// If N is greater than 1, second line continues at position VX, VY+1, and so on.
+				case 0xD000:
+				case 0xE000:
+					switch (opcode & 0x000F) {
+						case 0x000E: // 0xEX9E Skips the next instruction if the key stored in VX is pressed.
+						case 0x0001: // 0xEXA1 Skips the next instruction if the key stored in VX isn't pressed.
+						default: //unhandled for some reason
+							writefln("unknown opcode: 0x%x", opcode);
+							break;
+					}
+					break;
+				case 0xF000:
+					switch (opcode & 0x00FF) {
+						case 0x0007: // 0xFX07 Sets VX to the value of the delay timer.
+						case 0x000A: // 0xFX0A A key press is awaited, and then stored in VX.
+						case 0x0015: // 0xFX15 Sets the delay timer to VX.
+						case 0x0018: // 0xFX18 Sets the sound timer to VX.
+						case 0x001E: // 0xFX1E Adds VX to I.
+						case 0x0029: // 0xFX29 Sets I to the location of the sprite for the character in VX.
+						// 0xFX33 Stores the Binary-coded decimal representation of VX,
+						//  with the most significant of three digits at the address in I,
+						//  the middle digit at I plus 1, and the least significant digit at I plus 2.
+						case 0x0033:
+						case 0x0055: // 0xFX55 Stores V0 to VX in memory starting at address I.
+						case 0x0065: // 0xFX65 Fills V0 to VX with values from memory starting at address I.
+						default: // unhandled for some reason
+							writefln("unknown opcode: 0x%x", opcode);
+							break;
+					}
+					break;
+				default:
+					writefln("unknown opcode: 0x%x", opcode);
+			}
+		}
+		
+		return "";
+
+	} // dissassemble
+
+} // Assembler
+
 struct Chip8Status {
 
-	//emu ptr
+	// emu ptr
 	Emulator* run_;
 	Chip8* emu_;
 
+	// loaded program
+	const (char)* loaded_program;
+
 	// mem editor
 	// MemoryEditor mem_editor_;
 
@@ -389,6 +558,8 @@ struct Chip8Status {
 
 	void resetShortcut() {
 
+		loaded_program = null;
+
 		emu_.reset();
 		
 	} // resetShortcut
@@ -397,6 +568,7 @@ struct Chip8Status {
 
 		import std.file : read;
 
+		loaded_program = "chip8_picture.ch8";
 		auto buf = read("programs/chip8_picture.ch8");
 		emu_.load(0x200, buf); // do ze load yes, will copy all the data in
 
@@ -463,14 +635,19 @@ struct Chip8Status {
 			igBegin("Emulator Status");
 
 			igBeginChild("General");
-			igText("OpCode: 0x%04X", emu_.cpu.opcode);
+			if (!loaded_program) {
-			igText("PC:");
+				igText("Loaded Program: none");
+			} else {
+				igText("Loaded Program: %s", loaded_program);
+			}
+			igText("Opcode: 0x%04X", emu_.cpu.opcode);
 			igSameLine();
-			igText("pc: 0x%04X (%hu)", emu_.cpu.pc, emu_.cpu.pc);
+			igText("| PC: 0x%04X (%hu)", emu_.cpu.pc, emu_.cpu.pc);
 			// igDragInt("##pc", cast(int*)&emu_.cpu.pc, 0.5f, 0, emu_.ram.length);
 
 			igText("Registers (v0 - vF)");
 			igColumns(4, null, false);
+			igIndent();
 
 			auto n = 0;
 			foreach (ref chunk; emu_.cpu.v[].chunks(4)) {
@@ -483,12 +660,24 @@ struct Chip8Status {
 			}
 
 			igColumns(1, null, false);
+			igUnindent();
 
 			igText("Index Register: 0x%04X", emu_.cpu.i);
 			igText("Delay Timer: 0x%04X", emu_.cpu.delay_timer);
 			igText("Sound Timer: 0x%04X", emu_.cpu.sound_timer);
 
-			if(igButton("Step")) {
+			if (igButton("Reload")) {
+				resetShortcut();
+				loadShortcut();
+			}
+
+			igSameLine();
+
+			if (igButton("Reset")) {
+				resetShortcut();
+			}
+
+			if (igButton("Step")) {
 				emu_.step();
 			}