CpuCore.cs

using System;
using System.Threading;
using System.Threading.Tasks;

namespace ProcessorEmulator
{
    /// <summary>
    /// Minimal CPU Core for boot simulation and instruction execution
    /// Provides realistic boot sequence simulation for firmware validation
    /// </summary>
    public class CpuCore
    {
        private byte[] loadedFirmware;
        private bool isRunning = false;
        private MemoryMap memory;
        
        public string Architecture { get; set; } = "Universal";
        public int ClockSpeed { get; set; } = 1000; // MHz
        public bool IsRunning => isRunning;
        
        public event Action<string> OnInstruction;
        public event Action<string> OnBoot;
        
        public void LoadFirmware(byte[] firmware)
        {
            loadedFirmware = firmware;
            memory = new MemoryMap(firmware);
            
            Console.WriteLine($"✅ Firmware loaded: {firmware.Length:N0} bytes");
            Console.WriteLine($"🧠 Memory map initialized: {memory.RAM.Length / 1024:N0}KB RAM");
            OnBoot?.Invoke($"Firmware loaded: {firmware.Length:N0} bytes");
        }
        
        public async Task ExecuteAsync()
        {
            if (loadedFirmware == null)
            {
                throw new InvalidOperationException("No firmware loaded. Call LoadFirmware() first.");
            }
            
            isRunning = true;
            Console.WriteLine("🚀 Starting CPU execution...");
            OnBoot?.Invoke("CPU execution started");
            
            try
            {
                // Simulate realistic boot sequence
                await SimulateBootSequence();
                
                // Execute main firmware instructions
                await ExecuteMainLoop();
            }
            finally
            {
                isRunning = false;
                Console.WriteLine("⏹️ CPU execution stopped");
                OnBoot?.Invoke("CPU execution completed");
            }
        }
        
        private async Task SimulateBootSequence()
        {
            var bootSteps = new[]
            {
                "RESET: CPU reset vector",
                "INIT: Initialize registers",
                "CACHE: Enable instruction cache",
                "MMU: Setup memory management",
                "LOAD: Loading bootloader",
                "VERIFY: Firmware signature check",
                "JUMP: Jumping to main code"
            };
            
            foreach (var step in bootSteps)
            {
                Console.WriteLine($"⚡ {step}");
                OnInstruction?.Invoke(step);
                await Task.Delay(200); // Realistic boot timing
            }
        }
        
        private async Task ExecuteMainLoop()
        {
            Console.WriteLine("🔄 Entering main execution loop...");
            
            for (int cycle = 0; cycle < 20; cycle++)
            {
                if (!isRunning) break;
                
                string instruction = cycle switch
                {
                    < 5 => $"LOAD R{cycle % 4}, #{cycle * 0x1000:X4}",
                    < 10 => $"ADD R{cycle % 4}, R{(cycle + 1) % 4}",
                    < 15 => $"MOV R{cycle % 4}, [0x{cycle * 0x100:X4}]",
                    _ => $"NOP ; cycle {cycle}"
                };
                
                Console.WriteLine($"🔧 Cycle {cycle:D2}: {instruction}");
                OnInstruction?.Invoke($"Cycle {cycle:D2}: {instruction}");
                
                // Simulate realistic instruction timing
                await Task.Delay(100);
            }
            
            Console.WriteLine("✅ Main execution loop complete");
        }
        
        public void Stop()
        {
            isRunning = false;
            Console.WriteLine("🛑 CPU stop requested");
        }
        
        public void Reset()
        {
            Stop();
            loadedFirmware = null;
            memory = null;
            Console.WriteLine("🔄 CPU core reset");
            OnBoot?.Invoke("CPU core reset");
        }
    }
}