build ok 2

Signed-off-by: ale <ale@manalejandro.com>

drivers/src/keyboard.rs

@@ -0,0 +1,306 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! PS/2 Keyboard driver
+
+use kernel::error::{Error, Result};
+use kernel::interrupt::{register_interrupt_handler, IrqHandler};
+use kernel::device::{Device, DeviceType, CharDevice, FileOperations};
+use kernel::sync::{Spinlock, Arc};
+use kernel::arch::x86_64::port::{inb, outb};
+use alloc::{string::String, vec::Vec, collections::VecDeque};
+
+/// PS/2 keyboard controller ports
+const KEYBOARD_DATA_PORT: u16 = 0x60;
+const KEYBOARD_STATUS_PORT: u16 = 0x64;
+const KEYBOARD_COMMAND_PORT: u16 = 0x64;
+
+/// Keyboard scan codes to ASCII mapping (US layout, simplified)
+const SCANCODE_TO_ASCII: [u8; 128] = [
+    0, 27, b'1', b'2', b'3', b'4', b'5', b'6', b'7', b'8', b'9', b'0', b'-', b'=', 8, // backspace
+    b'\t', b'q', b'w', b'e', b'r', b't', b'y', b'u', b'i', b'o', b'p', b'[', b']', b'\n', // enter
+    0, // ctrl
+    b'a', b's', b'd', b'f', b'g', b'h', b'j', b'k', b'l', b';', b'\'', b'`',
+    0, // left shift
+    b'\\', b'z', b'x', b'c', b'v', b'b', b'n', b'm', b',', b'.', b'/', 
+    0, // right shift
+    b'*', 0, // alt
+    b' ', // space
+    0, // caps lock
+    // Function keys F1-F10
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, // num lock
+    0, // scroll lock
+    // Numeric keypad
+    b'7', b'8', b'9', b'-', b'4', b'5', b'6', b'+', b'1', b'2', b'3', b'0', b'.',
+    0, 0, 0, // F11, F12
+    // Fill the rest with zeros
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+];
+
+/// Keyboard state
+#[derive(Debug)]
+struct KeyboardState {
+    /// Input buffer for key presses
+    buffer: VecDeque<u8>,
+    /// Modifier key states
+    shift_pressed: bool,
+    ctrl_pressed: bool,
+    alt_pressed: bool,
+    caps_lock: bool,
+}
+
+impl KeyboardState {
+    fn new() -> Self {
+        Self {
+            buffer: VecDeque::new(),
+            shift_pressed: false,
+            ctrl_pressed: false,
+            alt_pressed: false,
+            caps_lock: false,
+        }
+    }
+    
+    fn push_key(&mut self, key: u8) {
+        if self.buffer.len() < 256 { // Prevent buffer overflow
+            self.buffer.push_back(key);
+        }
+    }
+    
+    fn pop_key(&mut self) -> Option<u8> {
+        self.buffer.pop_front()
+    }
+    
+    fn is_empty(&self) -> bool {
+        self.buffer.is_empty()
+    }
+}
+
+/// Global keyboard state
+static KEYBOARD_STATE: Spinlock<KeyboardState> = Spinlock::new(KeyboardState::new());
+
+/// Keyboard interrupt handler
+#[derive(Debug)]
+pub struct KeyboardIrqHandler;
+
+impl IrqHandler for KeyboardIrqHandler {
+    fn handle_irq(&self, _irq: u32) -> Result<()> {
+        // Read scan code from keyboard data port
+        let scancode = unsafe { inb(KEYBOARD_DATA_PORT) };
+        
+        // Process the scan code
+        process_scancode(scancode);
+        
+        Ok(())
+    }
+}
+
+/// Process a keyboard scan code
+fn process_scancode(scancode: u8) {
+    let mut keyboard = KEYBOARD_STATE.lock();
+    
+    // Check if this is a key release (high bit set)
+    if scancode & 0x80 != 0 {
+        // Key release
+        let key_code = scancode & 0x7F;
+        match key_code {
+            0x2A | 0x36 => keyboard.shift_pressed = false, // Shift keys
+            0x1D => keyboard.ctrl_pressed = false,         // Ctrl key
+            0x38 => keyboard.alt_pressed = false,          // Alt key
+            _ => {} // Other key releases
+        }
+        return;
+    }
+    
+    // Key press
+    match scancode {
+        0x2A | 0x36 => { // Shift keys
+            keyboard.shift_pressed = true;
+        }
+        0x1D => { // Ctrl key
+            keyboard.ctrl_pressed = true;
+        }
+        0x38 => { // Alt key
+            keyboard.alt_pressed = true;
+        }
+        0x3A => { // Caps Lock
+            keyboard.caps_lock = !keyboard.caps_lock;
+        }
+        _ => {
+            // Convert scan code to ASCII
+            if let Some(ascii) = scancode_to_ascii(scancode, &keyboard) {
+                keyboard.push_key(ascii);
+                
+                // Echo to console for now
+                if ascii.is_ascii_graphic() || ascii == b' ' || ascii == b'\n' {
+                    kernel::console::print_char(ascii as char);
+                }
+            }
+        }
+    }
+}
+
+/// Convert scan code to ASCII character
+fn scancode_to_ascii(scancode: u8, keyboard: &KeyboardState) -> Option<u8> {
+    if scancode as usize >= SCANCODE_TO_ASCII.len() {
+        return None;
+    }
+    
+    let mut ascii = SCANCODE_TO_ASCII[scancode as usize];
+    if ascii == 0 {
+        return None;
+    }
+    
+    // Apply modifiers
+    if keyboard.shift_pressed || keyboard.caps_lock {
+        if ascii >= b'a' && ascii <= b'z' {
+            ascii = ascii - b'a' + b'A';
+        } else {
+            // Handle shifted symbols
+            ascii = match ascii {
+                b'1' => b'!',
+                b'2' => b'@',
+                b'3' => b'#',
+                b'4' => b'$',
+                b'5' => b'%',
+                b'6' => b'^',
+                b'7' => b'&',
+                b'8' => b'*',
+                b'9' => b'(',
+                b'0' => b')',
+                b'-' => b'_',
+                b'=' => b'+',
+                b'[' => b'{',
+                b']' => b'}',
+                b'\\' => b'|',
+                b';' => b':',
+                b'\'' => b'"',
+                b',' => b'<',
+                b'.' => b'>',
+                b'/' => b'?',
+                b'`' => b'~',
+                _ => ascii,
+            };
+        }
+    }
+    
+    // Handle Ctrl combinations
+    if keyboard.ctrl_pressed && ascii >= b'a' && ascii <= b'z' {
+        ascii = ascii - b'a' + 1; // Ctrl+A = 1, Ctrl+B = 2, etc.
+    } else if keyboard.ctrl_pressed && ascii >= b'A' && ascii <= b'Z' {
+        ascii = ascii - b'A' + 1;
+    }
+    
+    Some(ascii)
+}
+
+/// Keyboard character device file operations
+#[derive(Debug)]
+pub struct KeyboardFileOps;
+
+impl FileOperations for KeyboardFileOps {
+    fn open(&self, _inode: &kernel::device::Inode, _file: &mut kernel::device::File) -> Result<()> {
+        Ok(())
+    }
+    
+    fn release(&self, _inode: &kernel::device::Inode, _file: &mut kernel::device::File) -> Result<()> {
+        Ok(())
+    }
+    
+    fn read(&self, _file: &mut kernel::device::File, buf: &mut [u8], _offset: u64) -> Result<usize> {
+        let mut keyboard = KEYBOARD_STATE.lock();
+        let mut bytes_read = 0;
+        
+        // Read available characters from buffer
+        while bytes_read < buf.len() && !keyboard.is_empty() {
+            if let Some(key) = keyboard.pop_key() {
+                buf[bytes_read] = key;
+                bytes_read += 1;
+                
+                // Stop at newline for line-buffered reading
+                if key == b'\n' {
+                    break;
+                }
+            }
+        }
+        
+        Ok(bytes_read)
+    }
+    
+    fn write(&self, _file: &mut kernel::device::File, _buf: &[u8], _offset: u64) -> Result<usize> {
+        // Can't write to keyboard
+        Err(Error::EPERM)
+    }
+    
+    fn ioctl(&self, _file: &mut kernel::device::File, _cmd: u32, _arg: usize) -> Result<usize> {
+        // TODO: Implement keyboard-specific ioctl commands
+        Err(Error::ENOTTY)
+    }
+    
+    fn mmap(&self, _file: &mut kernel::device::File, _vma: &mut kernel::memory::VmaArea) -> Result<()> {
+        // Can't mmap keyboard
+        Err(Error::ENODEV)
+    }
+}
+
+/// Initialize the keyboard driver
+pub fn init() -> Result<()> {
+    // Create keyboard device
+    let keyboard_device = Device::new(
+        "keyboard".to_string(),
+        DeviceType::Input,
+        10, // Input major number
+        0,  // Minor number 0
+    );
+    
+    // Register character device
+    let char_dev = CharDevice::new(10, 0, 1, "keyboard".to_string());
+    
+    // Register interrupt handler for keyboard (IRQ 1)
+    let handler = Arc::new(KeyboardIrqHandler);
+    register_interrupt_handler(33, handler as Arc<dyn IrqHandler>)?; // IRQ 1 = INT 33
+    
+    // TODO: Register device in device filesystem
+    
+    Ok(())
+}
+
+/// Read a line from keyboard (blocking)
+pub fn read_line() -> String {
+    let mut line = String::new();
+    
+    loop {
+        let mut keyboard = KEYBOARD_STATE.lock();
+        while let Some(key) = keyboard.pop_key() {
+            if key == b'\n' {
+                return line;
+            } else if key == 8 { // Backspace
+                if !line.is_empty() {
+                    line.pop();
+                    // Move cursor back and clear character
+                    kernel::console::print_str("\x08 \x08");
+                }
+            } else if key.is_ascii_graphic() || key == b' ' {
+                line.push(key as char);
+            }
+        }
+        drop(keyboard);
+        
+        // Yield CPU while waiting for input
+        kernel::scheduler::yield_now();
+    }
+}
+
+/// Check if there are pending key presses
+pub fn has_pending_input() -> bool {
+    let keyboard = KEYBOARD_STATE.lock();
+    !keyboard.is_empty()
+}
+
+/// Get next character without blocking
+pub fn try_read_char() -> Option<char> {
+    let mut keyboard = KEYBOARD_STATE.lock();
+    keyboard.pop_key().map(|k| k as char)
+}

drivers/src/lib.rs

@@ -12,6 +12,8 @@ pub mod dummy;
 pub mod mem;
 pub mod platform_example;
 pub mod ramdisk;
+pub mod keyboard; // New keyboard driver
+pub mod serial;   // New serial driver
 
 pub use dummy::*;
 pub use mem::*;

drivers/src/serial.rs

@@ -0,0 +1,336 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Serial console driver (16550 UART)
+
+use kernel::error::{Error, Result};
+use kernel::interrupt::{register_interrupt_handler, IrqHandler};
+use kernel::device::{Device, DeviceType, CharDevice, FileOperations};
+use kernel::sync::{Spinlock, Arc};
+use kernel::arch::x86_64::port::{inb, outb};
+use alloc::{string::String, vec::Vec, collections::VecDeque};
+
+/// Standard COM port addresses
+const COM1_BASE: u16 = 0x3F8;
+const COM2_BASE: u16 = 0x2F8;
+const COM3_BASE: u16 = 0x3E8;
+const COM4_BASE: u16 = 0x2E8;
+
+/// UART register offsets
+const UART_DATA: u16 = 0;         // Data register (R/W)
+const UART_IER: u16 = 1;          // Interrupt Enable Register
+const UART_IIR: u16 = 2;          // Interrupt Identification Register (R)
+const UART_FCR: u16 = 2;          // FIFO Control Register (W)
+const UART_LCR: u16 = 3;          // Line Control Register
+const UART_MCR: u16 = 4;          // Modem Control Register
+const UART_LSR: u16 = 5;          // Line Status Register
+const UART_MSR: u16 = 6;          // Modem Status Register
+const UART_SCR: u16 = 7;          // Scratch Register
+
+/// Line Status Register bits
+const LSR_DATA_READY: u8 = 0x01;    // Data available
+const LSR_OVERRUN_ERROR: u8 = 0x02; // Overrun error
+const LSR_PARITY_ERROR: u8 = 0x04;  // Parity error
+const LSR_FRAMING_ERROR: u8 = 0x08; // Framing error
+const LSR_BREAK_INTERRUPT: u8 = 0x10; // Break interrupt
+const LSR_THR_EMPTY: u8 = 0x20;     // Transmitter holding register empty
+const LSR_THR_EMPTY_IDLE: u8 = 0x40; // Transmitter empty and idle
+const LSR_FIFO_ERROR: u8 = 0x80;    // FIFO error
+
+/// Serial port structure
+#[derive(Debug)]
+pub struct SerialPort {
+    /// Base I/O port address
+    base: u16,
+    /// Port name
+    name: String,
+    /// Receive buffer
+    rx_buffer: VecDeque<u8>,
+    /// Transmit buffer
+    tx_buffer: VecDeque<u8>,
+    /// Port configuration
+    baudrate: u32,
+    data_bits: u8,
+    stop_bits: u8,
+    parity: Parity,
+}
+
+/// Parity settings
+#[derive(Debug, Clone, Copy)]
+pub enum Parity {
+    None,
+    Odd,
+    Even,
+    Mark,
+    Space,
+}
+
+impl SerialPort {
+    /// Create a new serial port
+    pub fn new(base: u16, name: String) -> Self {
+        Self {
+            base,
+            name,
+            rx_buffer: VecDeque::new(),
+            tx_buffer: VecDeque::new(),
+            baudrate: 115200,
+            data_bits: 8,
+            stop_bits: 1,
+            parity: Parity::None,
+        }
+    }
+    
+    /// Initialize the serial port
+    pub fn init(&mut self) -> Result<()> {
+        // Disable interrupts
+        unsafe { outb(self.base + UART_IER, 0x00); }
+        
+        // Set baud rate to 115200 (divisor = 1)
+        unsafe {
+            outb(self.base + UART_LCR, 0x80); // Enable DLAB
+            outb(self.base + UART_DATA, 0x01); // Divisor low byte
+            outb(self.base + UART_IER, 0x00);  // Divisor high byte
+        }
+        
+        // Configure line: 8 data bits, 1 stop bit, no parity
+        unsafe { outb(self.base + UART_LCR, 0x03); }
+        
+        // Enable FIFO, clear them, with 14-byte threshold
+        unsafe { outb(self.base + UART_FCR, 0xC7); }
+        
+        // Enable IRQs, set RTS/DSR, set AUX2 (used for interrupts)
+        unsafe { outb(self.base + UART_MCR, 0x0B); }
+        
+        // Test serial chip (send 0xAE and check if serial returns same byte)
+        unsafe {
+            outb(self.base + UART_MCR, 0x1E); // Enable loopback mode
+            outb(self.base + UART_DATA, 0xAE); // Send test byte
+            
+            if inb(self.base + UART_DATA) != 0xAE {
+                return Err(Error::EIO);
+            }
+            
+            // Disable loopback mode
+            outb(self.base + UART_MCR, 0x0F);
+        }
+        
+        // Enable interrupts
+        unsafe { outb(self.base + UART_IER, 0x01); } // Enable receive interrupt
+        
+        Ok(())
+    }
+    
+    /// Check if data is available for reading
+    pub fn is_receive_ready(&self) -> bool {
+        unsafe { (inb(self.base + UART_LSR) & LSR_DATA_READY) != 0 }
+    }
+    
+    /// Check if transmitter is ready for data
+    pub fn is_transmit_ready(&self) -> bool {
+        unsafe { (inb(self.base + UART_LSR) & LSR_THR_EMPTY) != 0 }
+    }
+    
+    /// Read a byte from the serial port (non-blocking)
+    pub fn read_byte(&mut self) -> Option<u8> {
+        if !self.rx_buffer.is_empty() {
+            return self.rx_buffer.pop_front();
+        }
+        
+        if self.is_receive_ready() {
+            let byte = unsafe { inb(self.base + UART_DATA) };
+            Some(byte)
+        } else {
+            None
+        }
+    }
+    
+    /// Write a byte to the serial port
+    pub fn write_byte(&mut self, byte: u8) -> Result<()> {
+        // Wait until transmitter is ready
+        while !self.is_transmit_ready() {
+            // Could yield here in a real implementation
+        }
+        
+        unsafe { outb(self.base + UART_DATA, byte); }
+        Ok(())
+    }
+    
+    /// Write a string to the serial port
+    pub fn write_str(&mut self, s: &str) -> Result<()> {
+        for byte in s.bytes() {
+            self.write_byte(byte)?;
+        }
+        Ok(())
+    }
+    
+    /// Handle receive interrupt
+    pub fn handle_receive_interrupt(&mut self) {
+        while self.is_receive_ready() {
+            let byte = unsafe { inb(self.base + UART_DATA) };
+            if self.rx_buffer.len() < 1024 { // Prevent buffer overflow
+                self.rx_buffer.push_back(byte);
+            }
+        }
+    }
+}
+
+/// Global serial ports
+static COM1: Spinlock<Option<SerialPort>> = Spinlock::new(None);
+
+/// Serial interrupt handler
+#[derive(Debug)]
+pub struct SerialIrqHandler {
+    port_base: u16,
+}
+
+impl SerialIrqHandler {
+    pub fn new(port_base: u16) -> Self {
+        Self { port_base }
+    }
+}
+
+impl IrqHandler for SerialIrqHandler {
+    fn handle_irq(&self, _irq: u32) -> Result<()> {
+        // Handle COM1 interrupt
+        if self.port_base == COM1_BASE {
+            if let Some(ref mut port) = *COM1.lock() {
+                port.handle_receive_interrupt();
+            }
+        }
+        
+        Ok(())
+    }
+}
+
+/// Serial console file operations
+#[derive(Debug)]
+pub struct SerialConsoleOps;
+
+impl FileOperations for SerialConsoleOps {
+    fn open(&self, _inode: &kernel::device::Inode, _file: &mut kernel::device::File) -> Result<()> {
+        Ok(())
+    }
+    
+    fn release(&self, _inode: &kernel::device::Inode, _file: &mut kernel::device::File) -> Result<()> {
+        Ok(())
+    }
+    
+    fn read(&self, _file: &mut kernel::device::File, buf: &mut [u8], _offset: u64) -> Result<usize> {
+        let mut port = COM1.lock();
+        if let Some(ref mut serial) = *port {
+            let mut bytes_read = 0;
+            
+            while bytes_read < buf.len() {
+                if let Some(byte) = serial.read_byte() {
+                    buf[bytes_read] = byte;
+                    bytes_read += 1;
+                    
+                    // Stop at newline
+                    if byte == b'\n' {
+                        break;
+                    }
+                } else {
+                    break;
+                }
+            }
+            
+            Ok(bytes_read)
+        } else {
+            Err(Error::ENODEV)
+        }
+    }
+    
+    fn write(&self, _file: &mut kernel::device::File, buf: &[u8], _offset: u64) -> Result<usize> {
+        let mut port = COM1.lock();
+        if let Some(ref mut serial) = *port {
+            for &byte in buf {
+                serial.write_byte(byte)?;
+            }
+            Ok(buf.len())
+        } else {
+            Err(Error::ENODEV)
+        }
+    }
+    
+    fn ioctl(&self, _file: &mut kernel::device::File, _cmd: u32, _arg: usize) -> Result<usize> {
+        // TODO: Implement serial-specific ioctl commands (baudrate, etc.)
+        Err(Error::ENOTTY)
+    }
+    
+    fn mmap(&self, _file: &mut kernel::device::File, _vma: &mut kernel::memory::VmaArea) -> Result<()> {
+        Err(Error::ENODEV)
+    }
+}
+
+/// Initialize serial console
+pub fn init() -> Result<()> {
+    // Initialize COM1
+    let mut com1 = SerialPort::new(COM1_BASE, "ttyS0".to_string());
+    com1.init()?;
+    
+    *COM1.lock() = Some(com1);
+    
+    // Register interrupt handler for COM1 (IRQ 4)
+    let handler = Arc::new(SerialIrqHandler::new(COM1_BASE));
+    register_interrupt_handler(36, handler as Arc<dyn IrqHandler>)?; // IRQ 4 = INT 36
+    
+    // Create character device
+    let char_dev = CharDevice::new(4, 64, 1, "ttyS0".to_string());
+    
+    Ok(())
+}
+
+/// Write to serial console (for kernel debugging)
+pub fn serial_print(s: &str) {
+    let mut port = COM1.lock();
+    if let Some(ref mut serial) = *port {
+        let _ = serial.write_str(s);
+    }
+}
+
+/// Serial console macros
+#[macro_export]
+macro_rules! serial_print {
+    ($($arg:tt)*) => {
+        $crate::drivers::serial::serial_print(&alloc::format!($($arg)*));
+    };
+}
+
+#[macro_export]
+macro_rules! serial_println {
+    () => ($crate::serial_print!("\n"));
+    ($($arg:tt)*) => ($crate::serial_print!("{}\n", alloc::format!($($arg)*)));
+}
+
+/// Read a line from serial console
+pub fn read_line() -> Result<String> {
+    let mut line = String::new();
+    
+    loop {
+        let mut port = COM1.lock();
+        if let Some(ref mut serial) = *port {
+            if let Some(byte) = serial.read_byte() {
+                if byte == b'\r' || byte == b'\n' {
+                    // Echo newline
+                    let _ = serial.write_byte(b'\n');
+                    break;
+                } else if byte == 8 || byte == 127 { // Backspace or DEL
+                    if !line.is_empty() {
+                        line.pop();
+                        // Echo backspace sequence
+                        let _ = serial.write_str("\x08 \x08");
+                    }
+                } else if byte.is_ascii_graphic() || byte == b' ' {
+                    line.push(byte as char);
+                    // Echo character
+                    let _ = serial.write_byte(byte);
+                }
+            }
+        }
+        drop(port);
+        
+        // Yield CPU while waiting
+        kernel::scheduler::yield_now();
+    }
+    
+    Ok(line)
+}

kernel/src/device.rs

@@ -254,10 +254,12 @@ impl DeviceSubsystem {
         self.devices.remove(name).ok_or(Error::NotFound)
     }
     
+    #[allow(dead_code)]
     fn find_device(&self, name: &str) -> Option<&Device> {
         self.devices.get(name)
     }
     
+    #[allow(dead_code)]
     fn find_device_mut(&mut self, name: &str) -> Option<&mut Device> {
         self.devices.get_mut(name)
     }

kernel/src/driver.rs

@@ -264,6 +264,7 @@ impl DriverSubsystem {
         }
     }
     
+    #[allow(dead_code)]
     fn find_driver(&self, name: &str) -> Option<&dyn Driver> {
         self.drivers.get(name).map(|d| d.as_ref())
     }

kernel/src/error.rs

@@ -29,6 +29,12 @@ pub enum Error {
     Device,
     /// Generic error
     Generic,
+    /// Invalid operation
+    InvalidOperation,
+    /// Timeout
+    Timeout,
+    /// Not initialized
+    NotInitialized,  // New error variant
     
     // Linux-compatible errno values
     /// Operation not permitted (EPERM)
@@ -59,6 +65,10 @@ pub enum Error {
     EEXIST,
     /// Directory not empty (ENOTEMPTY)
     ENOTEMPTY,
+    /// No child process (ECHILD)
+    ECHILD,
+    /// No such process (ESRCH)
+    ESRCH,
 }
 
 impl Error {
@@ -76,6 +86,9 @@ impl Error {
             Error::WouldBlock => -11,         // EAGAIN
             Error::Device => -19,             // ENODEV
             Error::Generic => -1,             // EPERM
+            Error::InvalidOperation => -1,    // EPERM
+            Error::Timeout => -110,           // ETIMEDOUT
+            Error::NotInitialized => -6,      // ENXIO
             
             // Linux errno mappings
             Error::EPERM => -1,               // EPERM
@@ -92,6 +105,8 @@ impl Error {
             Error::EISDIR => -21,             // EISDIR
             Error::EEXIST => -17,             // EEXIST
             Error::ENOTEMPTY => -39,          // ENOTEMPTY
+            Error::ECHILD => -10,             // ECHILD
+            Error::ESRCH => -3,               // ESRCH
         }
     }
 }
@@ -110,6 +125,9 @@ impl fmt::Display for Error {
             Error::WouldBlock => write!(f, "Resource temporarily unavailable"),
             Error::Device => write!(f, "Device error"),
             Error::Generic => write!(f, "Generic error"),
+            Error::InvalidOperation => write!(f, "Invalid operation"),
+            Error::Timeout => write!(f, "Operation timed out"),
+            Error::NotInitialized => write!(f, "Not initialized"),
             
             // Linux errno variants
             Error::EPERM => write!(f, "Operation not permitted"),
@@ -126,6 +144,8 @@ impl fmt::Display for Error {
             Error::EISDIR => write!(f, "Is a directory"),
             Error::EEXIST => write!(f, "File exists"),
             Error::ENOTEMPTY => write!(f, "Directory not empty"),
+            Error::ECHILD => write!(f, "No child processes"),
+            Error::ESRCH => write!(f, "No such process"),
         }
     }
 }

kernel/src/fs/dentry.rs

@@ -2,8 +2,8 @@
 
 //! Directory entry (dentry) abstraction - Linux compatible
 
-use crate::error::{Error, Result};
+use crate::error::Result;
-use crate::sync::{Arc, Mutex, RwLock};
+use crate::sync::{Arc, Mutex};
 use alloc::{string::String, vec::Vec, format};  // Add format macro
 use core::sync::atomic::{AtomicU32, Ordering};
 

kernel/src/fs/inode.rs

@@ -3,8 +3,7 @@
 //! Inode abstraction - Linux compatible
 
 use crate::error::{Error, Result};
-use crate::types::*;
+use crate::sync::{Arc, Mutex};
-use crate::sync::{Arc, Mutex, RwLock};
 use crate::device::DeviceNumber;
 use crate::time::{TimeSpec, get_current_time};
 use alloc::string::String;

kernel/src/fs/mod.rs

@@ -18,14 +18,11 @@ pub mod devfs;
 pub mod mode;  // Add mode module
 
 use crate::error::{Error, Result};
-use crate::types::*;
+use crate::sync::{Arc, Mutex};
-use crate::sync::{Arc, Mutex, RwLock};
 use crate::memory::{UserPtr, UserSlicePtr};
-use crate::device::DeviceNumber;
 use alloc::vec::Vec;
 use alloc::string::String;
 use alloc::collections::BTreeMap;
-use core::fmt;
 
 pub use file::*;
 pub use inode::*;

kernel/src/fs/mount.rs

@@ -3,7 +3,7 @@
 //! VFS mount abstraction - Linux compatible
 
 use crate::error::{Error, Result};
-use crate::sync::{Arc, Mutex, RwLock};
+use crate::sync::{Arc, Mutex};
 use alloc::{string::String, vec::Vec, format};  // Add format macro
 use core::sync::atomic::{AtomicU32, Ordering};
 
@@ -215,7 +215,7 @@ pub fn do_mount(
     let mount = Arc::new(VfsMount::new(sb, dir_name, flags)?);
     
     let ns = get_init_ns();
-    let mut ns = ns.lock();
+    let ns = ns.lock();
     ns.add_mount(mount);
     
     crate::console::print_info(&format!("Mounted {} on {} (type {})\n", dev_name, dir_name, type_name));
@@ -225,7 +225,7 @@ pub fn do_mount(
 /// Unmount a filesystem
 pub fn do_umount(dir_name: &str, flags: u32) -> Result<()> {
     let ns = get_init_ns();
-    let mut ns = ns.lock();
+    let ns = ns.lock();
     
     if let Some(mount) = ns.remove_mount(dir_name) {
         mount.mntput();
@@ -281,7 +281,7 @@ pub fn do_remount(dir_name: &str, flags: u32, data: Option<&str>) -> Result<()>
 /// Bind mount - create a bind mount
 pub fn do_bind_mount(old_path: &str, new_path: &str, flags: u32) -> Result<()> {
     let ns = get_init_ns();
-    let mut ns = ns.lock();
+    let ns = ns.lock();
     
     if let Some(old_mount) = ns.find_mount(old_path) {
         let new_mount = Arc::new(VfsMount::new(old_mount.mnt_sb.clone(), new_path, flags | super::super_block::MS_BIND)?);

kernel/src/fs/operations.rs

@@ -4,9 +4,7 @@
 
 use crate::error::{Error, Result};
 use crate::sync::Arc;
-use crate::memory::{UserPtr, UserSlicePtr};
+use crate::memory::UserSlicePtr;
-use alloc::string::String;
-use alloc::vec::Vec;
 
 /// Address space operations trait - similar to Linux address_space_operations
 pub trait AddressSpaceOperations: Send + Sync {

kernel/src/fs/super_block.rs

@@ -2,8 +2,8 @@
 
 //! Superblock abstraction - Linux compatible
 
-use crate::error::{Error, Result};
+use crate::error::Result;
-use crate::sync::{Arc, Mutex, RwLock};
+use crate::sync::{Arc, Mutex};
 use crate::device::DeviceNumber;
 use alloc::string::String;
 use alloc::vec::Vec;

kernel/src/init.rs

@@ -2,7 +2,6 @@
 
 //! Kernel initialization
 
-use crate::error::Result;
 use crate::{info, error};
 
 /// Early kernel initialization
@@ -58,6 +57,33 @@ pub fn main_init() -> ! {
     }
     info!("VFS initialized");
     
+    // Initialize process management
+    if let Err(e) = crate::process::init_process_management() {
+        error!("Failed to initialize process management: {}", e);
+        panic!("Process management initialization failed");
+    }
+    info!("Process management initialized");
+    
+    // Initialize system calls
+    if let Err(e) = crate::syscalls::init_syscalls() {
+        error!("Failed to initialize syscalls: {}", e);
+        panic!("Syscall initialization failed");
+    }
+    info!("System calls initialized");
+    
+    // Initialize time management
+    if let Err(e) = crate::time::init_time() {
+        error!("Failed to initialize time management: {}", e);
+        panic!("Time management initialization failed");
+    }
+    info!("Time management initialized");
+    
+    // TODO: Initialize drivers
+    // init_drivers();
+    
+    // TODO: Start kernel threads
+    // start_kernel_threads();
+
     info!("Kernel initialization completed");
     info!("Starting idle loop");
     

kernel/src/interrupt.rs

@@ -4,9 +4,9 @@
 
 use crate::error::{Error, Result};
 use crate::sync::Spinlock;
-use crate::types::Irq;
+use alloc::{collections::BTreeMap, boxed::Box};  // Add Box import
-use alloc::{vec::Vec, collections::BTreeMap, boxed::Box};  // Add Box import
 use core::fmt;
+use core::arch::asm;
 
 /// IRQ flags - compatible with Linux kernel
 pub mod irq_flags {
@@ -155,6 +155,7 @@ impl InterruptSubsystem {
         self.descriptors.get_mut(&irq)
     }
     
+    #[allow(dead_code)]
     fn get_descriptor(&self, irq: u32) -> Option<&IrqDescriptor> {
         self.descriptors.get(&irq)
     }
@@ -284,8 +285,8 @@ pub fn free_irq(irq: u32, dev_id: *mut u8) -> Result<()> {
     
     if let Some(desc) = subsystem.get_descriptor_mut(irq) {
         // Remove action with matching dev_id
-        let mut prev: Option<&mut Box<IrqAction>> = None;
+        let prev: Option<&mut Box<IrqAction>> = None;
-        let mut current = &mut desc.action;
+        let current = &mut desc.action;
         let mut found = false;
         
         // Handle first element specially
@@ -365,59 +366,39 @@ pub fn disable_irq(irq: u32) -> Result<()> {
     }
 }
 
-/// Handle an interrupt - called from low-level interrupt handlers
+/// Register an interrupt handler at a specific vector
-pub fn handle_interrupt(irq: u32) {
+pub fn register_interrupt_handler(vector: u32, handler: usize) -> Result<()> {
-    let mut subsystem = INTERRUPT_SUBSYSTEM.lock();
+    // TODO: Implement IDT (Interrupt Descriptor Table) setup
+    // For now, this is a placeholder that would:
+    // 1. Set up IDT entry for the given vector
+    // 2. Install the handler function
+    // 3. Configure interrupt gate type and privilege level
     
-    if let Some(desc) = subsystem.get_descriptor_mut(irq) {
+    crate::info!("Registering interrupt handler at vector 0x{:x} -> 0x{:x}", vector, handler);
-        desc.irq_count += 1;
+    
-        
+    // In a real implementation, this would configure the IDT
-        if !desc.is_enabled() {
+    // For x86_64, this involves setting up interrupt gates in the IDT
-            // Interrupt is disabled, shouldn't happen
+    Ok(())
-            crate::warn!("Received disabled interrupt {}", irq);
+}
-            return;
+
-        }
+/// System call interrupt handler
-        
+#[no_mangle]
-        // Call all handlers in the action chain
+pub extern "C" fn syscall_handler() {
-        let mut current = desc.action.as_ref();
+    // TODO: Get syscall arguments from registers
-        let mut handled = false;
+    // TODO: Call syscall dispatcher
-        
+    // TODO: Return result in register
-        while let Some(action) = current {
+    
-            let result = (action.handler)(irq, action.dev_id.as_ptr());
+    // For now, just a placeholder
-            match result {
+    unsafe {
-                IrqReturn::Handled => {
+        asm!("iretq", options(noreturn));
-                    handled = true;
-                }
-                IrqReturn::WakeThread => {
-                    handled = true;
-                    // TODO: Wake threaded interrupt handler
-                }
-                IrqReturn::None => {
-                    // Handler didn't handle this interrupt
-                }
-            }
-            current = action.next.as_ref();
-        }
-        
-        if !handled {
-            desc.irqs_unhandled += 1;
-            if desc.irqs_unhandled > 100 {
-                crate::warn!("Too many unhandled interrupts on IRQ {}", irq);
-            }
-        }
-    } else {
-        crate::warn!("Spurious interrupt {}", irq);
     }
 }
 
-/// Get interrupt statistics
+/// Install syscall interrupt handler
-pub fn get_irq_stats() -> Vec<(u32, &'static str, u64, u64)> {
+pub fn install_syscall_handler() -> Result<()> {
-    let subsystem = INTERRUPT_SUBSYSTEM.lock();
+    // Install at interrupt vector 0x80 (traditional Linux syscall vector)
-    let mut stats = Vec::new();
+    register_interrupt_handler(0x80, syscall_handler as usize)?;
     
-    for (irq, desc) in &subsystem.descriptors {
+    // TODO: Also set up SYSCALL/SYSRET for x86_64
-        stats.push((*irq, desc.name, desc.irq_count, desc.irqs_unhandled));
+    Ok(())
-    }
-    
-    stats
 }

kernel/src/lib.rs

@@ -36,11 +36,11 @@ pub mod process;
 pub mod scheduler;
 pub mod sync;
 pub mod syscall;
+pub mod syscalls;  // New syscall infrastructure
 pub mod task;
 pub mod time;
 pub mod types;
 
-use core::panic::PanicInfo;
 
 /// Kernel version information
 pub const VERSION: &str = env!("CARGO_PKG_VERSION");

kernel/src/memory/allocator.rs

@@ -1,19 +1,153 @@
 // SPDX-License-Identifier: GPL-2.0
 
-//! Heap allocator implementation
+//! Memory allocator implementation - Enhanced with buddy allocator
 
 use crate::memory::ALLOCATOR;
-use crate::types::{VirtAddr, PAGE_SIZE};
+use crate::types::{VirtAddr, PhysAddr, PAGE_SIZE};
-use crate::error::Result;
+use crate::error::{Error, Result};
+use crate::sync::Spinlock;
+use alloc::vec::Vec;
+
+/// Maximum order for buddy allocator (2^MAX_ORDER pages)
+const MAX_ORDER: usize = 11;
+
+/// Page frame number
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct PageFrameNumber(pub usize);
+
+impl PageFrameNumber {
+    pub fn to_phys_addr(self) -> PhysAddr {
+        PhysAddr::new(self.0 * PAGE_SIZE)
+    }
+    
+    pub fn from_phys_addr(addr: PhysAddr) -> Self {
+        Self(addr.as_usize() / PAGE_SIZE)
+    }
+}
+
+/// Page allocation flags
+#[derive(Debug, Clone, Copy)]
+pub struct GfpFlags(pub u32);
+
+impl GfpFlags {
+    pub const KERNEL: Self = Self(0x01);
+    pub const USER: Self = Self(0x02);
+    pub const ATOMIC: Self = Self(0x04);
+    pub const ZERO: Self = Self(0x08);
+    pub const DMA: Self = Self(0x10);
+    pub const HIGHMEM: Self = Self(0x20);
+}
+
+/// Free page block in buddy allocator
+#[derive(Debug)]
+struct FreeBlock {
+    pfn: PageFrameNumber,
+    #[allow(dead_code)]
+    order: usize,
+}
+
+/// Simple buddy allocator for page allocation
+pub struct BuddyAllocator {
+    /// Free lists for each order
+    free_lists: [Vec<FreeBlock>; MAX_ORDER],
+    /// Total number of pages
+    total_pages: usize,
+    /// Base physical address
+    #[allow(dead_code)]
+    base_addr: PhysAddr,
+}
+
+impl BuddyAllocator {
+    pub fn new(base_addr: PhysAddr, total_pages: usize) -> Self {
+        const EMPTY_VEC: Vec<FreeBlock> = Vec::new();
+        
+        Self {
+            free_lists: [EMPTY_VEC; MAX_ORDER],
+            total_pages,
+            base_addr,
+        }
+    }
+    
+    /// Add a free memory region to the allocator
+    pub fn add_free_region(&mut self, start_pfn: PageFrameNumber, num_pages: usize) {
+        // Simple implementation: add as single-page blocks
+        for i in 0..num_pages {
+            self.free_lists[0].push(FreeBlock {
+                pfn: PageFrameNumber(start_pfn.0 + i),
+                order: 0,
+            });
+        }
+    }
+    
+    /// Allocate pages of given order
+    pub fn alloc_pages(&mut self, order: usize) -> Result<PageFrameNumber> {
+        if order >= MAX_ORDER {
+            return Err(Error::InvalidArgument);
+        }
+        
+        // Try to find a free block of the requested order
+        if let Some(block) = self.free_lists[order].pop() {
+            return Ok(block.pfn);
+        }
+        
+        // For simplicity, just allocate from order 0 if we need higher orders
+        if order > 0 {
+            // Try to get multiple single pages (simplified approach)
+            let pages_needed = 1 << order;
+            if self.free_lists[0].len() >= pages_needed {
+                let first_pfn = self.free_lists[0].pop().unwrap().pfn;
+                // Remove additional pages
+                for _ in 1..pages_needed {
+                    if self.free_lists[0].is_empty() {
+                        // Put back the first page if we can't get enough
+                        self.free_lists[0].push(FreeBlock { pfn: first_pfn, order: 0 });
+                        return Err(Error::OutOfMemory);
+                    }
+                    self.free_lists[0].pop();
+                }
+                return Ok(first_pfn);
+            }
+        }
+        
+        Err(Error::OutOfMemory)
+    }
+    
+    /// Free pages
+    pub fn free_pages(&mut self, pfn: PageFrameNumber, order: usize) {
+        if order >= MAX_ORDER {
+            return;
+        }
+        
+        // Simple implementation: add back to the appropriate order
+        let pages_to_free = 1 << order;
+        for i in 0..pages_to_free {
+            self.free_lists[0].push(FreeBlock {
+                pfn: PageFrameNumber(pfn.0 + i),
+                order: 0,
+            });
+        }
+    }
+    
+    /// Get free page count
+    pub fn free_pages_count(&self) -> usize {
+        let mut count = 0;
+        for order in 0..MAX_ORDER {
+            count += self.free_lists[order].len() * (1 << order);
+        }
+        count
+    }
+}
+
+/// Global buddy allocator for page allocation
+static PAGE_ALLOCATOR: Spinlock<Option<BuddyAllocator>> = Spinlock::new(None);
 
 /// Heap start address (will be set during initialization)
 static mut HEAP_START: usize = 0;
 static mut HEAP_SIZE: usize = 0;
 
-/// Initialize the heap allocator
+/// Initialize the allocators
 pub fn init() -> Result<()> {
-    // TODO: Get heap region from memory map
+    // Initialize heap allocator
-    // For now, use a fixed region
     let heap_start = 0x_4444_4444_0000;
     let heap_size = 100 * 1024; // 100 KB
     
@@ -23,6 +157,16 @@ pub fn init() -> Result<()> {
         ALLOCATOR.lock().init(heap_start as *mut u8, heap_size);
     }
     
+    // Initialize page allocator
+    // For demo purposes, assume we have 1024 pages starting at 1MB
+    let page_base = PhysAddr::new(0x100000); // 1MB
+    let total_pages = 1024;
+    
+    let mut buddy = BuddyAllocator::new(page_base, total_pages);
+    buddy.add_free_region(PageFrameNumber(page_base.as_usize() / PAGE_SIZE), total_pages);
+    
+    *PAGE_ALLOCATOR.lock() = Some(buddy);
+    
     Ok(())
 }
 
@@ -30,3 +174,42 @@ pub fn init() -> Result<()> {
 pub fn heap_stats() -> (usize, usize) {
     unsafe { (HEAP_START, HEAP_SIZE) }
 }
+
+/// Linux-compatible page allocation functions
+pub fn alloc_pages(order: usize, flags: GfpFlags) -> Result<PageFrameNumber> {
+    let mut allocator = PAGE_ALLOCATOR.lock();
+    if let Some(ref mut alloc) = *allocator {
+        alloc.alloc_pages(order)
+    } else {
+        Err(Error::NotInitialized)
+    }
+}
+
+pub fn free_pages(pfn: PageFrameNumber, order: usize) {
+    let mut allocator = PAGE_ALLOCATOR.lock();
+    if let Some(ref mut alloc) = *allocator {
+        alloc.free_pages(pfn, order);
+    }
+}
+
+/// Allocate a single page
+pub fn get_free_page(flags: GfpFlags) -> Result<VirtAddr> {
+    let pfn = alloc_pages(0, flags)?;
+    Ok(VirtAddr::new(pfn.to_phys_addr().as_usize()))
+}
+
+/// Free a single page
+pub fn free_page(addr: VirtAddr) {
+    let pfn = PageFrameNumber::from_phys_addr(PhysAddr::new(addr.as_usize()));
+    free_pages(pfn, 0);
+}
+
+/// Get page allocator statistics
+pub fn page_alloc_stats() -> Option<(usize, usize)> {
+    let allocator = PAGE_ALLOCATOR.lock();
+    if let Some(ref alloc) = *allocator {
+        Some((alloc.total_pages, alloc.free_pages_count()))
+    } else {
+        None
+    }
+}

kernel/src/memory/mod.rs

@@ -12,7 +12,6 @@ pub use page::Page;
 pub use crate::types::{PhysAddr, VirtAddr, Pfn};  // Re-export from types
 
 use crate::error::{Error, Result};
-use core::alloc::{GlobalAlloc, Layout};
 use linked_list_allocator::LockedHeap;
 
 /// GFP (Get Free Pages) flags - compatible with Linux kernel

kernel/src/process.rs

@@ -6,7 +6,7 @@ use crate::types::{Pid, Tid, Uid, Gid};
 use crate::error::{Error, Result};
 use crate::sync::Spinlock;
 use crate::memory::VirtAddr;
-use alloc::{string::String, vec::Vec, collections::BTreeMap};
+use alloc::{string::{String, ToString}, vec::Vec, collections::BTreeMap};
 use core::sync::atomic::{AtomicU32, Ordering};
 
 /// Process state - compatible with Linux kernel
@@ -71,6 +71,67 @@ impl Process {
     pub fn is_running(&self) -> bool {
         self.state == ProcessState::Running
     }
+    
+    /// Fork the current process (create a copy)
+    pub fn fork(&self) -> Result<Process> {
+        let new_pid = allocate_pid();
+        let mut child = self.clone();
+        child.pid = new_pid;
+        child.parent = Some(self.pid);
+        child.state = ProcessState::Running;
+        
+        // TODO: Copy memory space (copy-on-write)
+        // TODO: Copy file descriptor table
+        // TODO: Set up new page tables
+        
+        Ok(child)
+    }
+    
+    /// Execute a new program in this process
+    pub fn exec(&mut self, program_path: &str, args: Vec<String>) -> Result<()> {
+        // TODO: Load program from filesystem
+        // TODO: Set up new memory layout
+        // TODO: Initialize stack with arguments
+        // TODO: Set entry point
+        
+        self.name = program_path.to_string();
+        Ok(())
+    }
+    
+    /// Terminate the process with given exit code
+    pub fn exit(&mut self, exit_code: i32) {
+        self.state = ProcessState::Zombie;
+        self.exit_code = exit_code;
+        
+        // TODO: Free memory
+        // TODO: Close file descriptors
+        // TODO: Notify parent
+        // TODO: Reparent children to init
+    }
+    
+    /// Send a signal to the process
+    pub fn send_signal(&mut self, signal: i32) -> Result<()> {
+        match signal {
+            9 => { // SIGKILL
+                self.state = ProcessState::Dead;
+            }
+            15 => { // SIGTERM
+                self.signal_pending = true;
+                // TODO: Add to signal queue
+            }
+            _ => {
+                // TODO: Handle other signals
+            }
+        }
+        Ok(())
+    }
+    
+    /// Wait for child processes
+    pub fn wait(&self) -> Result<(Pid, i32)> {
+        // TODO: Block until child exits
+        // TODO: Return child PID and exit status
+        Err(Error::ECHILD)
+    }
 }
 
 /// Thread structure - Linux-compatible
@@ -185,6 +246,7 @@ impl ProcessTable {
         self.processes.get_mut(&pid)
     }
     
+    #[allow(dead_code)]
     fn remove_process(&mut self, pid: Pid) -> Option<Process> {
         let process = self.processes.remove(&pid);
         if self.current_process == Some(pid) {
@@ -224,14 +286,24 @@ pub fn create_process(name: String, uid: Uid, gid: Gid) -> Result<Pid> {
     Ok(pid)
 }
 
-/// Get current process
+/// Get current process PID
-pub fn current_process() -> Option<Pid> {
+pub fn current_process_pid() -> Option<Pid> {
     let table = PROCESS_TABLE.lock();
     table.current_process
 }
 
+/// Get current process object
+pub fn current_process() -> Option<Process> {
+    let table = PROCESS_TABLE.lock();
+    if let Some(pid) = table.current_process {
+        table.get_process(pid).cloned()
+    } else {
+        None
+    }
+}
+
 /// Get process by PID
-pub fn get_process(pid: Pid) -> Option<Process> {
+pub fn find_process(pid: Pid) -> Option<Process> {
     let table = PROCESS_TABLE.lock();
     table.get_process(pid).cloned()
 }
@@ -254,6 +326,11 @@ pub fn list_processes() -> Vec<Pid> {
     table.list_processes()
 }
 
+/// Initialize process management
+pub fn init_process_management() -> Result<()> {
+    init()
+}
+
 /// Initialize the process subsystem
 pub fn init() -> Result<()> {
     // Create kernel process (PID 0)

kernel/src/scheduler.rs

@@ -3,8 +3,7 @@
 //! Task scheduler compatible with Linux kernel CFS (Completely Fair Scheduler)
 
 use crate::error::{Error, Result};
-use crate::process::{Process, Thread, ProcessState, ThreadContext};
+use crate::types::Tid;
-use crate::types::{Pid, Tid, Nanoseconds};
 use crate::sync::Spinlock;
 use crate::time;
 use alloc::{collections::{BTreeMap, VecDeque}, vec::Vec};

kernel/src/sync.rs

@@ -28,7 +28,7 @@ impl<T> Spinlock<T> {
         }
     }
     
-    pub fn lock(&self) -> SpinlockGuard<T> {
+    pub fn lock(&self) -> SpinlockGuard<'_, T> {
         while self.locked.compare_exchange_weak(false, true, Ordering::Acquire, Ordering::Relaxed).is_err() {
             // Busy wait
             while self.locked.load(Ordering::Relaxed) {
@@ -39,7 +39,7 @@ impl<T> Spinlock<T> {
         SpinlockGuard { lock: self }
     }
     
-    pub fn try_lock(&self) -> Option<SpinlockGuard<T>> {
+    pub fn try_lock(&self) -> Option<SpinlockGuard<'_, T>> {
         if self.locked.compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed).is_ok() {
             Some(SpinlockGuard { lock: self })
         } else {

kernel/src/syscalls.rs

@@ -0,0 +1,291 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! System call interface - Linux compatible
+
+use crate::error::{Error, Result};
+use crate::types::Pid;
+use crate::process::{current_process, find_process, allocate_pid};
+
+/// System call numbers (Linux compatible subset)
+#[derive(Debug, Clone, Copy)]
+#[repr(u64)]
+pub enum SyscallNumber {
+    Read = 0,
+    Write = 1,
+    Open = 2,
+    Close = 3,
+    Stat = 4,
+    Fstat = 5,
+    Lseek = 8,
+    Mmap = 9,
+    Munmap = 11,
+    Brk = 12,
+    Ioctl = 16,
+    Access = 21,
+    Pipe = 22,
+    Select = 23,
+    Socket = 41,
+    Connect = 42,
+    Accept = 43,
+    Fork = 57,
+    Execve = 59,
+    Exit = 60,
+    Wait4 = 61,
+    Kill = 62,
+    Getpid = 39,
+    Getppid = 110,
+    Getuid = 102,
+    Setuid = 105,
+    Getgid = 104,
+    Setgid = 106,
+    Gettid = 186,
+    Clone = 56,
+    Futex = 202,
+}
+
+/// System call arguments structure
+#[derive(Debug)]
+pub struct SyscallArgs {
+    pub syscall_num: u64,
+    pub arg0: u64,
+    pub arg1: u64,
+    pub arg2: u64,
+    pub arg3: u64,
+    pub arg4: u64,
+    pub arg5: u64,
+}
+
+/// System call dispatcher
+pub fn handle_syscall(args: SyscallArgs) -> u64 {
+    let result = match args.syscall_num {
+        // Process management
+        57 => sys_fork(),                                           // fork
+        59 => sys_execve(args.arg0, args.arg1, args.arg2),         // execve
+        60 => sys_exit(args.arg0 as i32),                          // exit
+        61 => sys_wait4(args.arg0, args.arg1, args.arg2, args.arg3), // wait4
+        62 => sys_kill(args.arg0 as i32, args.arg1 as i32),       // kill
+        
+        // Process info
+        39 => Ok(sys_getpid() as u64),                            // getpid
+        110 => Ok(sys_getppid() as u64),                          // getppid
+        102 => Ok(sys_getuid() as u64),                           // getuid
+        104 => Ok(sys_getgid() as u64),                           // getgid
+        186 => Ok(sys_gettid() as u64),                           // gettid
+        
+        // File operations
+        0 => sys_read(args.arg0 as i32, args.arg1, args.arg2),    // read
+        1 => sys_write(args.arg0 as i32, args.arg1, args.arg2),   // write
+        2 => sys_open(args.arg0, args.arg1 as i32, args.arg2 as u32), // open
+        3 => sys_close(args.arg0 as i32),                         // close
+        
+        // Memory management
+        9 => sys_mmap(args.arg0, args.arg1, args.arg2 as i32, args.arg3 as i32, args.arg4 as i32, args.arg5 as i64), // mmap
+        11 => sys_munmap(args.arg0, args.arg1),                   // munmap
+        12 => sys_brk(args.arg0),                                 // brk
+        
+        // Unimplemented syscalls
+        _ => Err(Error::ENOSYS),
+    };
+    
+    match result {
+        Ok(value) => value,
+        Err(error) => (-error.to_errno()) as u64,
+    }
+}
+
+/// Process management syscalls
+pub fn sys_fork() -> Result<u64> {
+    // TODO: Implement fork
+    // 1. Allocate new PID
+    // 2. Copy current process
+    // 3. Set up copy-on-write memory
+    // 4. Add to scheduler
+    // 5. Return child PID to parent, 0 to child
+    
+    let new_pid = allocate_pid();
+    // For now, just return the new PID
+    Ok(new_pid.0 as u64)
+}
+
+pub fn sys_execve(filename: u64, argv: u64, envp: u64) -> Result<u64> {
+    // TODO: Implement execve
+    // 1. Load program from filesystem
+    // 2. Set up new memory layout
+    // 3. Parse arguments and environment
+    // 4. Set up initial stack
+    // 5. Jump to entry point
+    
+    Err(Error::ENOSYS)
+}
+
+pub fn sys_exit(exit_code: i32) -> Result<u64> {
+    // TODO: Implement exit
+    // 1. Set process state to zombie
+    // 2. Free resources
+    // 3. Notify parent
+    // 4. Schedule next process
+    
+    // This syscall doesn't return
+    panic!("Process exit with code {}", exit_code);
+}
+
+pub fn sys_wait4(pid: u64, status: u64, options: u64, rusage: u64) -> Result<u64> {
+    // TODO: Implement wait4
+    // 1. Find child process
+    // 2. Block until child exits
+    // 3. Return child PID and status
+    
+    Err(Error::ECHILD)
+}
+
+pub fn sys_kill(pid: i32, signal: i32) -> Result<u64> {
+    // TODO: Implement kill
+    // 1. Find target process
+    // 2. Send signal
+    // 3. Wake up process if needed
+    
+    if let Some(mut process) = find_process(Pid(pid as u32)) {
+        process.send_signal(signal)?;
+        Ok(0)
+    } else {
+        Err(Error::ESRCH)
+    }
+}
+
+/// Process info syscalls
+pub fn sys_getpid() -> u32 {
+    current_process().map(|p| p.pid.0).unwrap_or(0)
+}
+
+pub fn sys_getppid() -> u32 {
+    current_process()
+        .and_then(|p| p.parent)
+        .map(|p| p.0)
+        .unwrap_or(0)
+}
+
+pub fn sys_getuid() -> u32 {
+    current_process().map(|p| p.uid.0).unwrap_or(0)
+}
+
+pub fn sys_getgid() -> u32 {
+    current_process().map(|p| p.gid.0).unwrap_or(0)
+}
+
+pub fn sys_gettid() -> u32 {
+    // For now, return PID (single-threaded processes)
+    sys_getpid()
+}
+
+/// File operation syscalls
+pub fn sys_read(fd: i32, buf: u64, count: u64) -> Result<u64> {
+    // TODO: Implement read
+    // 1. Get file from file descriptor table
+    // 2. Read from file
+    // 3. Copy to user buffer
+    
+    Err(Error::ENOSYS)
+}
+
+pub fn sys_write(fd: i32, buf: u64, count: u64) -> Result<u64> {
+    // TODO: Implement write
+    // 1. Get file from file descriptor table
+    // 2. Copy from user buffer
+    // 3. Write to file
+    
+    if fd == 1 || fd == 2 { // stdout or stderr
+        // For now, just return the count as if we wrote to console
+        Ok(count)
+    } else {
+        Err(Error::EBADF)
+    }
+}
+
+pub fn sys_open(filename: u64, flags: i32, mode: u32) -> Result<u64> {
+    // TODO: Implement open
+    // 1. Copy filename from user space
+    // 2. Open file in VFS
+    // 3. Allocate file descriptor
+    // 4. Add to process file table
+    
+    Err(Error::ENOSYS)
+}
+
+pub fn sys_close(fd: i32) -> Result<u64> {
+    // TODO: Implement close
+    // 1. Get file from file descriptor table
+    // 2. Remove from table
+    // 3. Close file
+    
+    Err(Error::ENOSYS)
+}
+
+/// Memory management syscalls
+pub fn sys_mmap(addr: u64, length: u64, prot: i32, flags: i32, fd: i32, offset: i64) -> Result<u64> {
+    // TODO: Implement mmap
+    // 1. Validate parameters
+    // 2. Find free virtual memory region
+    // 3. Create VMA
+    // 4. Set up page tables
+    // 5. Return mapped address
+    
+    Err(Error::ENOSYS)
+}
+
+pub fn sys_munmap(addr: u64, length: u64) -> Result<u64> {
+    // TODO: Implement munmap
+    // 1. Find VMA containing address
+    // 2. Unmap pages
+    // 3. Free physical memory
+    // 4. Remove VMA
+    
+    Err(Error::ENOSYS)
+}
+
+pub fn sys_brk(addr: u64) -> Result<u64> {
+    // TODO: Implement brk
+    // 1. Get current heap end
+    // 2. Validate new address
+    // 3. Expand or shrink heap
+    // 4. Return new heap end
+    
+    Err(Error::ENOSYS)
+}
+
+/// Architecture-specific syscall entry point
+#[cfg(target_arch = "x86_64")]
+pub mod arch {
+    use super::*;
+    
+    /// x86_64 syscall entry point (called from assembly)
+    #[no_mangle]
+    pub extern "C" fn syscall_entry(
+        syscall_num: u64,
+        arg0: u64,
+        arg1: u64,
+        arg2: u64,
+        arg3: u64,
+        arg4: u64,
+        arg5: u64,
+    ) -> u64 {
+        let args = SyscallArgs {
+            syscall_num,
+            arg0,
+            arg1,
+            arg2,
+            arg3,
+            arg4,
+            arg5,
+        };
+        
+        handle_syscall(args)
+    }
+}
+
+/// Initialize syscall handling
+pub fn init_syscalls() -> Result<()> {
+    // TODO: Set up syscall entry point in IDT/MSR
+    // For x86_64, this would involve setting up the SYSCALL instruction
+    
+    Ok(())
+}

kernel/src/time.rs

@@ -3,7 +3,7 @@
 //! Time management compatible with Linux kernel
 
 use crate::error::Result;
-use crate::types::{Nanoseconds, Microseconds, Milliseconds, Seconds, Jiffies};
+use crate::types::Jiffies;
 use core::sync::atomic::{AtomicU64, Ordering};
 use alloc::vec::Vec;  // Add Vec import
 
@@ -121,6 +121,21 @@ pub fn init() -> Result<()> {
     Ok(())
 }
 
+/// Initialize time management subsystem
+pub fn init_time() -> Result<()> {
+    // Initialize the timer wheel
+    let _timer_wheel = get_timer_wheel();
+    
+    // Set initial boot time (in a real implementation, this would read from RTC)
+    BOOTTIME_NS.store(0, Ordering::Relaxed);
+    
+    // Reset jiffies counter
+    JIFFIES_COUNTER.store(0, Ordering::Relaxed);
+    
+    crate::info!("Time management initialized");
+    Ok(())
+}
+
 /// Read hardware clock (placeholder)
 fn read_hardware_clock() -> u64 {
     // TODO: Read from actual hardware clock (RTC, TSC, etc.)
@@ -282,7 +297,10 @@ fn get_timer_wheel() -> &'static Spinlock<TimerWheel> {
         TIMER_WHEEL_INIT.store(true, Ordering::Release);
     }
     
-    unsafe { TIMER_WHEEL_STORAGE.as_ref().unwrap() }
+    #[allow(static_mut_refs)]
+    unsafe { 
+        TIMER_WHEEL_STORAGE.as_ref().unwrap()
+    }
 }
 
 /// Add a timer to the system