Update src/userprog/syscall.c

src/userprog/syscall.c

 #include "userprog/syscall.h"
 #include <stdio.h>
 #include <syscall-nr.h>
+#include "devices/shutdown.h"
+#include "threads/synch.h"
 #include "threads/interrupt.h"
 #include "threads/thread.h"
+#include "userprog/process.h"
+#include "filesys/filesys.h"
 
+typedef int pid_p;
+static struct lock f_lock;
 static void syscall_handler (struct intr_frame *);
+static uint32_t load_stack(struct intr_frame *f, int offset);
+
+/*Function for system call*/
+void syscall_halt(void);
+void syscall_exit(int);
+int syscall_wait (pid_p pid);
+bool syscall_create (const char *file, unsigned initial_size);
+/*End of system call function*/
 
 void
 syscall_init (void) 
@@ -12,10 +26,71 @@ syscall_init (void)
   intr_register_int (0x30, 3, INTR_ON, syscall_handler, "syscall");
 }
 
+static uint32_t load_stack(struct intr_frame *f, int offset)
+{
+  return *((uint32_t*)(f->esp + offset));
+}
+
 
 static void
 syscall_handler (struct intr_frame *f UNUSED)
 {
-  printf ("system call!\n");
+  int code = (int)load_stack(f, 0);
+  lock_init(&f_lock);                      
+  switch (code)                             
+  {
+   case SYS_HALT:      
+    {
+    syscall_halt();
+    break;
+    }
+   case SYS_EXIT:
+    {
+    syscall_exit((int)load_stack(f,4));
+    break;
+    }
+   
+   case SYS_WAIT: 
+    {
+    f->eax = syscall_wait((int)load_stack(f,4));
+    break;
+    }
+   case SYS_CREATE:  
+    {
+    f->eax = syscall_create((const char*)load_stack(f,4), (unsigned)load_stack(f,8));
+    break;
+    }
+   
+   default:
+    {
+	printf ("system call (%d) not implemented!\n", code);
   	thread_exit ();
     }
+  }
+}
+
+void syscall_halt (void)
+{
+	shutdown_power_off();
+}
+
+void syscall_exit (int status)
+{
+	struct thread *cur = thread_current ();
+	cur->exit_status = status;
+	thread_exit();
+}
+
+int syscall_wait (pid_p pid)
+{
+	return process_wait (pid);
+}
+
+bool syscall_create (const char *file, unsigned initial_size)
+{
+  lock_acquire(&f_lock);
+  bool success = filesys_create(file, initial_size);
+  lock_release(&f_lock);
+  return success;
+}
+