syscall_handler(): parse syscall number

1 files changed, 10 insertions, 1 deletions

diff --git a/src/userprog/syscall.c b/src/userprog/syscall.c
index 370c89b..e15555e 100644
--- a/src/userprog/syscall.c
+++ b/src/userprog/syscall.c
@@ -15,6 +15,15 @@ syscall_init (void)
 static void
 syscall_handler (struct intr_frame *f UNUSED) 
 {
-  printf ("system call!\n");
+  int syscall_number = *((int *)f->esp);
+  switch (syscall_number) {
+    case 9:
+      // printf
+      printf ("printf: %s", *((char **)(f->esp+8)));
+      break;
+    default:
+      printf ("kernel: unknown syscall '%d'\n", syscall_number);
+      break;
+  }
   thread_exit ();
 }