A update

drivers/isr.c

@@ -0,0 +1,42 @@
+#include <port_io.h>
+#include <stdio.h>
+
+#include <isr.h>
+
+
+void (*irq_handlers[256])(isr_stack_t *r) = { 0 };
+
+void register_interrupt_handler(uint8_t n, void (*handler)(isr_stack_t *))
+{
+  irq_handlers[n] = handler;
+}
+
+void isr_handler(isr_stack_t *r)
+{
+  if (irq_handlers[r->int_no]) {
+    irq_handlers[r->int_no](r);
+  } else {
+    printf("Unhandled interrupt: %d\n", r->int_no);
+  }
+
+
+  /* Send EOI to PIC */
+  if (r->int_no >= 40)
+  {
+    outb(0xA0, 0x20);
+  }
+  if (r->int_no >= 32)
+  {
+    outb(0x20, 0x20);
+  }
+}
+
+void syscall_handler(regs_t *r)
+{
+  switch (r->eax) {
+    case 0: printf("Syscall: Hello world\n"); break;
+    case 1: printf("Syscall: value = %d\n", r->ebx); break;
+    default: printf("Unknown syscall %d\n", r->eax);
+  }
+}
+