feat: implement PS/2 keyboard & shell, dynamic heap (malloc/new), Zero-Copy SHM, and SMP multicore initialization

kernel/src/arch/idt.rs

@@ -52,6 +52,7 @@ static mut IDT: [IdtEntry; 256] = [IdtEntry::missing(); 256];
 extern "C" {
     fn default_isr_stub();
     fn timer_isr_entry();
+    fn keyboard_isr_entry();
 }
 
 // Global assembly ISR stub for default exception handling
@@ -92,6 +93,10 @@ pub unsafe fn init() {
     let timer_addr = timer_isr_entry as *const () as usize as u64;
     (*idt_ptr.add(32)).set_handler(timer_addr, 0, 0);
 
+    // Set Keyboard Interrupt (Vector 33 / 0x21)
+    let kbd_addr = keyboard_isr_entry as *const () as usize as u64;
+    (*idt_ptr.add(33)).set_handler(kbd_addr, 0, 0);
+
     let descriptor = IdtDescriptor {
         limit: (size_of::<[IdtEntry; 256]>() - 1) as u16,
         base: idt_ptr as u64,
@@ -108,10 +113,7 @@ pub extern "C" fn raw_exception_handler(stack_ptr: *const u64) {
 #[no_mangle]
 pub extern "C" fn timer_interrupt_handler(saved_rsp: u64) -> u64 {
     unsafe {
-        // Send End of Interrupt to controller
         send_eoi();
-
-        // Perform preemptive scheduling quantum check
         let sched = &mut *core::ptr::addr_of_mut!(SCHEDULER);
         sched.preempt(saved_rsp)
     }