cpu - Change structure of CPU object to group State and Debug info
This commit is contained in:
n loewen
parent
2d210303e6
commit
b173d46cb6
233
src/cpu.js
233
src/cpu.js
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@ -16,39 +16,56 @@ const display = require('./display.js');
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// STATE
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const CPU = {
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// Core state
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running: false,
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IP: INITIAL_IP_ADDRESS,
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FLAGS: {'C': false, 'Z': false, 'N': false, 'O': false},
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FLAGNUMS2NAMES: {0: 'C', 1: 'Z', 2: 'N', 3: 'O'},
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Acc: 0,
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memory: null,
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// Functions that update core state
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/** Core state **/
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state: {
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running: false,
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IP: INITIAL_IP_ADDRESS,
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flags: {'C': false, 'Z': false, 'N': false, 'O': false},
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FLAGNUMS2NAMES: {0: 'C', 1: 'Z', 2: 'N', 3: 'O'},
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acc: 0,
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memory: null,
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},
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/** Debug info **/
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debug: {
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previousIP: 0,
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currentInstruction: {
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opcode: null,
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operand: null,
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mnemonic: null,
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},
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cycleCounter: 0,
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},
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/** Functions that update state **/
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/** @param {Uint8Array} data */
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loadMemory: (data) => {
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CPU.memory = new Uint8Array(256);
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CPU.memory.set(data, 0);
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loadMemory(data) {
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this.state.memory = new Uint8Array(256);
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this.state.memory.set(data, 0);
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},
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incrementIP: (offset) => {
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CPU.previousIP = CPU.IP;
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CPU.IP = CPU.IP + offset;
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},
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setIP: (address) => {
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CPU.previousIP = CPU.IP;
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CPU.IP = address;
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},
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updateFlagZero: () => { CPU.FLAGS.Z = CPU.Acc === 0; },
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updateFlagNegative: () => { CPU.Acc & 128 ? CPU.FLAGS.N = true : CPU.FLAGS.N = false },
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// Debug info
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previousIP: 0,
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currentInstruction: {
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opcode: null,
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operand: null,
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mnemonic: null,
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incrementIP(offset) {
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this.state.previousIP = this.state.IP;
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this.state.IP = this.state.IP + offset;
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},
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cycleCounter: 0,
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setIP(address) {
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this.state.previousIP = this.state.IP;
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this.state.IP = address;
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},
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updateFlagZero() { this.state.flags.Z = this.state.acc === 0; },
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updateFlagNegative() { this.state.acc & 128 ? this.state.flags.N = true : this.state.flags.N = false },
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/** Hooks **/
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onTickHooks: [],
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/** @param {function} fn **/
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onTick(fn) { this.onTickHooks.push(fn) },
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}
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@ -56,154 +73,154 @@ const CPU = {
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const Instructions = {
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end: () => {
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CPU.currentInstruction.mnemonic = 'END';
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CPU.running = false;
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CPU.debug.currentInstruction.mnemonic = 'END';
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CPU.state.running = false;
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CPU.incrementIP(2);
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},
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store_lit: (lit) => {
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CPU.currentInstruction.mnemonic = 'STO lit';
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CPU.memory[lit] = CPU.Acc;
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CPU.debug.currentInstruction.mnemonic = 'STO lit';
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CPU.state.memory[lit] = CPU.state.acc;
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CPU.incrementIP(2);
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},
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store_addr: (addr) => {
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CPU.currentInstruction.mnemonic = `STO addr; @addr: ${num2hex(CPU.memory[addr])}`;
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CPU.memory[CPU.memory[addr]] = CPU.Acc;
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CPU.debug.currentInstruction.mnemonic = `STO addr; @addr: ${num2hex(CPU.state.memory[addr])}`;
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CPU.state.memory[CPU.state.memory[addr]] = CPU.state.acc;
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CPU.incrementIP(2);
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},
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load_lit: (lit) => {
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CPU.currentInstruction.mnemonic = 'LDA lit';
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CPU.Acc = lit;
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CPU.debug.currentInstruction.mnemonic = 'LDA lit';
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CPU.state.acc = lit;
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CPU.updateFlagNegative();
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CPU.updateFlagZero();
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CPU.incrementIP(2);
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},
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load_addr: (addr) => {
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CPU.currentInstruction.mnemonic = `LDA addr; @ addr: ${num2hex(CPU.memory[addr])}`;
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CPU.Acc = CPU.memory[addr];
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CPU.debug.currentInstruction.mnemonic = `LDA addr; @ addr: ${num2hex(CPU.state.memory[addr])}`;
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CPU.state.acc = CPU.state.memory[addr];
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CPU.updateFlagNegative();
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CPU.updateFlagZero();
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CPU.incrementIP(2);
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},
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add_lit: (lit) => {
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CPU.currentInstruction.mnemonic = 'ADD lit';
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CPU.debug.currentInstruction.mnemonic = 'ADD lit';
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// Calculate sum
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let sum = CPU.Acc + lit;
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let sum = CPU.state.acc + lit;
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if (sum > 255) {
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CPU.FLAGS.C = true;
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CPU.state.flags.C = true;
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sum = (sum % 255) - 1;
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} else {
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CPU.FLAGS.C = false;
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CPU.state.flags.C = false;
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}
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// Calculate overflow flag status
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let bitSixCarry = 0;
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if ((CPU.Acc & 64) && (lit & 64)) { bitSixCarry = 1; }
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// let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
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if ((CPU.state.acc & 64) && (lit & 64)) { bitSixCarry = 1; }
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// let overflow = bitSixCarry ^ (CPU.state.flags & 8);
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// FIXME FIXME FIXME
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// I'm on a plane and can't remember how this works
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let overflow = 0;
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if (overflow) {
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CPU.FLAGS.O = true;
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CPU.state.flags.O = true;
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} else {
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CPU.FLAGS.O = false;
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CPU.state.flags.O = false;
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}
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CPU.Acc = sum;
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CPU.state.acc = sum;
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CPU.updateFlagNegative();
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CPU.updateFlagZero();
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CPU.incrementIP(2);
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},
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add_addr: (addr) => {
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CPU.currentInstruction.mnemonic = 'ADD addr';
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CPU.debug.currentInstruction.mnemonic = 'ADD addr';
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// Calculate sum
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let sum = CPU.Acc + CPU.memory[addr];
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let sum = CPU.state.acc + CPU.state.memory[addr];
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if (sum > 255) {
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CPU.FLAGS.C = true;
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CPU.state.flags.C = true;
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sum = (sum % 255) - 1;
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} else {
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CPU.FLAGS.C = false;
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CPU.state.flags.C = false;
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}
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// Calculate overflow flag status
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let bitSixCarry = 0;
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if ((CPU.Acc & 64) && (addr & 64)) { bitSixCarry = 1; }
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// let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
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if ((CPU.state.acc & 64) && (addr & 64)) { bitSixCarry = 1; }
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// let overflow = bitSixCarry ^ (CPU.state.flags & 8);
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// FIXME FIXME FIXME
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// I'm on a plane and can't remember how this works
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let overflow = 0;
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if (overflow) {
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CPU.FLAGS.O = true;
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CPU.state.flags.O = true;
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} else {
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CPU.FLAGS.O = false;
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CPU.state.flags.O = false;
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}
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CPU.Acc = sum;
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CPU.state.acc = sum;
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CPU.updateFlagNegative();
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CPU.updateFlagZero();
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CPU.incrementIP(2);
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},
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sub_lit: (lit) => {
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CPU.currentInstruction.mnemonic = 'SUB lit';
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CPU.debug.currentInstruction.mnemonic = 'SUB lit';
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// Calculate sum
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let sum = CPU.Acc - lit;
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let sum = CPU.state.acc - lit;
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if (sum < 0) {
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CPU.FLAGS.C = true;
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CPU.state.flags.C = true;
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sum = sum + 256;
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} else {
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CPU.FLAGS.C = false;
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CPU.state.flags.C = false;
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}
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// Calculate overflow flag status
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let bitSixCarry = 0;
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if ((CPU.Acc & 64) && (lit & 64)) { bitSixCarry = 1; }
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// let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
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if ((CPU.state.acc & 64) && (lit & 64)) { bitSixCarry = 1; }
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// let overflow = bitSixCarry ^ (CPU.state.flags & 8);
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// FIXME FIXME FIXME
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// I'm on a plane and can't remember how this works
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let overflow = 0;
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if (overflow) {
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CPU.FLAGS.O = true;
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CPU.state.flags.O = true;
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} else {
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CPU.FLAGS.O = false;
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CPU.state.flags.O = false;
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}
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CPU.Acc = sum;
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CPU.state.acc = sum;
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CPU.updateFlagNegative();
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CPU.updateFlagZero();
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CPU.incrementIP(2);
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},
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sub_addr: (addr) => {
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CPU.currentInstruction.mnemonic = 'SUB addr';
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CPU.debug.currentInstruction.mnemonic = 'SUB addr';
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// Calculate sum
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let sum = CPU.Acc - CPU.memory[addr];
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let sum = CPU.state.acc - CPU.state.memory[addr];
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if (sum < 0) {
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CPU.FLAGS.C = true;
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CPU.state.flags.C = true;
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sum = sum + 256;
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} else {
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CPU.FLAGS.C = false;
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CPU.state.flags.C = false;
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}
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// Calculate overflow flag status
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let bitSixCarry = 0;
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if ((CPU.Acc & 64) && (addr & 64)) { bitSixCarry = 1; }
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// let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
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if ((CPU.state.acc & 64) && (addr & 64)) { bitSixCarry = 1; }
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// let overflow = bitSixCarry ^ (CPU.state.flags & 8);
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// FIXME FIXME FIXME
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// I'm on a plane and can't remember how this works
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let overflow = 0;
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if (overflow) {
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CPU.FLAGS.O = true;
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CPU.state.flags.O = true;
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} else {
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CPU.FLAGS.O = false;
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CPU.state.flags.O = false;
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}
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CPU.Acc = sum;
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CPU.state.acc = sum;
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CPU.updateFlagNegative();
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CPU.updateFlagZero();
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CPU.incrementIP(2);
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},
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hop_lit: (lit) => {
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CPU.currentInstruction.mnemonic = `HOP lit; IP+2: ${CPU.memory[CPU.IP+2]}, IP+3: ${CPU.memory[CPU.IP+3]}`;
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if (CPU.Acc === lit) {
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CPU.debug.currentInstruction.mnemonic = `HOP lit; IP+2: ${CPU.state.memory[CPU.state.IP+2]}, IP+3: ${CPU.state.memory[CPU.state.IP+3]}`;
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if (CPU.state.acc === lit) {
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CPU.incrementIP(4);
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} else {
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CPU.incrementIP(2);
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@ -211,8 +228,8 @@ const Instructions = {
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},
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hop_addr: (addr) => {
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CPU.currentInstruction.mnemonic = 'HOP addr';
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if (CPU.Acc === CPU.memory[addr]) {
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CPU.debug.currentInstruction.mnemonic = 'HOP addr';
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if (CPU.state.acc === CPU.state.memory[addr]) {
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CPU.incrementIP(4);
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} else {
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CPU.incrementIP(2);
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@ -220,13 +237,13 @@ const Instructions = {
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},
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jump_lit: (lit) => {
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CPU.currentInstruction.mnemonic = 'JMP lit';
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CPU.debug.currentInstruction.mnemonic = 'JMP lit';
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CPU.setIP(lit);
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},
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jump_addr: (addr) => {
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CPU.currentInstruction.mnemonic = 'JMP addr';
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CPU.setIP(CPU.memory[addr]);
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CPU.debug.currentInstruction.mnemonic = 'JMP addr';
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CPU.setIP(CPU.state.memory[addr]);
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},
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flag_toggle: (flagNum) => {
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@ -235,8 +252,8 @@ const Instructions = {
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process.exit();
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}
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const flagName = CPU.FLAGNUMS2NAMES[flagNum];
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CPU.currentInstruction.mnemonic = `FTG ${flagName}`;
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CPU.FLAGS[flagName] = !CPU.FLAGS[flagName];
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CPU.debug.currentInstruction.mnemonic = `FTG ${flagName}`;
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CPU.state.flags[flagName] = !CPU.state.flags[flagName];
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CPU.incrementIP(2);
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},
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@ -246,8 +263,8 @@ const Instructions = {
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process.exit();
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}
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const flagName = CPU.FLAGNUMS2NAMES[flagNum];
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CPU.currentInstruction.mnemonic = `FHP ${flagName}; IP+2: ${CPU.memory[CPU.IP+2]}, IP+3: ${CPU.memory[CPU.IP+3]}`;
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if (CPU.FLAGS[CPU.FLAGNUMS2NAMES[flagNum]]) {
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CPU.debug.currentInstruction.mnemonic = `FHP ${flagName}; IP+2: ${CPU.state.memory[CPU.state.IP+2]}, IP+3: ${CPU.state.memory[CPU.state.IP+3]}`;
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if (CPU.state.flags[CPU.FLAGNUMS2NAMES[flagNum]]) {
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CPU.incrementIP(4);
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} else {
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CPU.incrementIP(2);
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@ -255,7 +272,7 @@ const Instructions = {
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},
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no_op: () => {
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CPU.currentInstruction.mnemonic = `NOP`;
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CPU.debug.currentInstruction.mnemonic = `NOP`;
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CPU.incrementIP(2);
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},
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}
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@ -280,13 +297,13 @@ const opcodes2mnemonics = {
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};
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/**
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* Load code into memory and set CPU state to "running"
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* Load code into memory and set CPU state to "state.running"
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* @param {Uint8Array} code - Machine code to load
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**/
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function startCPU(code) {
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CPU.loadMemory(code);
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CPU.cycleCounter = 0;
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CPU.running = true;
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CPU.debug.cycleCounter = 0;
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CPU.state.running = true;
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// FIXME: This conflicts with single-stepping
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// (you can single-step, but keys aren't passed
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@ -309,7 +326,7 @@ function startCPU(code) {
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if (key.sequence === '\x03') process.exit();
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let name = key.name.toUpperCase();
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if (name in KEY_MAP) {
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CPU.memory[KEYPAD_ADDR] = KEY_MAP[name];
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CPU.state.memory[KEYPAD_ADDR] = KEY_MAP[name];
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}
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});
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}
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@ -320,14 +337,14 @@ function startCPU(code) {
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* @param {Boolean} [debug] - Print machine status and the line of code being executed
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**/
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async function stepCPU(debugInfo, debug = false, prettyPrintDisplay = false) {
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if (CPU.IP >= CPU.memory.length) {
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if (CPU.state.IP >= CPU.state.memory.length) {
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console.error('HALTING - IP greater than memory size');
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CPU.running = false;
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CPU.state.running = false;
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process.exit();
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} else {
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CPU.currentInstruction.opcode = CPU.memory[CPU.IP];
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CPU.currentInstruction.operand = CPU.memory[CPU.IP+1];
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let executeInstruction = opcodes2mnemonics[CPU.currentInstruction.opcode];
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CPU.debug.currentInstruction.opcode = CPU.state.memory[CPU.state.IP];
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CPU.debug.currentInstruction.operand = CPU.state.memory[CPU.state.IP+1];
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let executeInstruction = opcodes2mnemonics[CPU.debug.currentInstruction.opcode];
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if (typeof executeInstruction === 'undefined') {
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let info = debugInfo[CPU.previousIP];
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console.error();
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@ -336,17 +353,17 @@ async function stepCPU(debugInfo, debug = false, prettyPrintDisplay = false) {
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console.error(` from line ${info.lineNumber}: ${info.source}`);
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process.exit();
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}
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executeInstruction(CPU.currentInstruction.operand);
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CPU.cycleCounter += 1;
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executeInstruction(CPU.debug.currentInstruction.operand);
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CPU.debug.cycleCounter += 1;
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}
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logCPUState(debugInfo, debug, prettyPrintDisplay);
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if (DEFAULT_CYCLE_LIMIT) { // Temporary limit as a lazy way to halt infinite loops
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if (CPU.cycleCounter >= DEFAULT_CYCLE_LIMIT) {
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if (CPU.debug.cycleCounter >= DEFAULT_CYCLE_LIMIT) {
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console.warn(' HALTING - reached cycle limit');
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CPU.running = false;
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CPU.state.running = false;
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}
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}
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if (!CPU.running) process.exit();
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if (!CPU.state.running) process.exit();
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}
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/**
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@ -366,7 +383,7 @@ exports.runProgram =
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// Animate the output by pausing between steps
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const loop = setInterval(async () => {
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stepCPU(debugInfo, debug, prettyPrint);
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if (!CPU.running) {
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if (!CPU.state.running) {
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logCPUState(debugInfo, debug, prettyPrint);
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console.log('Halted');
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process.exit();
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@ -383,7 +400,7 @@ exports.runProgram =
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**/
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exports.singleStepProgram = (code, debugInfo, debug = false, prettyPrintDisplay = false) => {
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startCPU(code);
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while (CPU.running) {
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while (CPU.state.running) {
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stepCPU(debugInfo, debug, prettyPrintDisplay);
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// FIXME: this prevents exiting with Ctrl+C:
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let key = readlineSync.keyIn('S to step, Q to quit > ', {
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@ -402,20 +419,20 @@ exports.singleStepProgram = (code, debugInfo, debug = false, prettyPrintDisplay
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**/
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function logCPUState(debugInfo, debug = false, prettyPrintDisplay = false) {
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debugInfo = debugInfo[CPU.previousIP] !== 'undefined' ? debugInfo[CPU.previousIP] : false;
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console.group(`Step ${CPU.cycleCounter}`);
|
||||
console.group(`Step ${CPU.debug.cycleCounter}`);
|
||||
console.log();
|
||||
if (!debug) console.clear();
|
||||
display.show(CPU.memory, prettyPrintDisplay);
|
||||
display.show(CPU.state.memory, prettyPrintDisplay);
|
||||
console.log();
|
||||
if (debugInfo) {
|
||||
console.log(`Line ${debugInfo.lineNumber}: ${debugInfo.source}`);
|
||||
console.log();
|
||||
}
|
||||
console.log('Mnemonic:', CPU.currentInstruction.mnemonic);
|
||||
console.log(`Machine: $${num2hex(CPU.currentInstruction.opcode)} $${num2hex(CPU.currentInstruction.operand)}`);
|
||||
console.log('Mnemonic:', CPU.debug.currentInstruction.mnemonic);
|
||||
console.log(`Machine: $${num2hex(CPU.debug.currentInstruction.opcode)} $${num2hex(CPU.debug.currentInstruction.operand)}`);
|
||||
console.log();
|
||||
console.log(`IP: $${num2hex(CPU.IP)} Acc: $${num2hex(CPU.Acc)} ONZC ${bool2bit(CPU.FLAGS.O)}${bool2bit(CPU.FLAGS.N)}${bool2bit(CPU.FLAGS.Z)}${bool2bit(CPU.FLAGS.C)}`);
|
||||
console.log(`KEY: $${num2hex(CPU.memory[KEYPAD_ADDR])} ${CPU.running ? "running" : "halted" }`);
|
||||
console.log(`IP: $${num2hex(CPU.state.IP)} Acc: $${num2hex(CPU.state.acc)} ONZC ${bool2bit(CPU.state.flags.O)}${bool2bit(CPU.state.flags.N)}${bool2bit(CPU.state.flags.Z)}${bool2bit(CPU.state.flags.C)}`);
|
||||
console.log(`KEY: $${num2hex(CPU.state.memory[KEYPAD_ADDR])} ${CPU.state.running ? "state.running" : "halted" }`);
|
||||
console.log();
|
||||
console.log();
|
||||
console.groupEnd();
|
||||
|
|
|
|||
Loading…
Reference in New Issue