diff --git a/kernel/syscall.c b/kernel/syscall.c
index ad511e1..5c578d0 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -152,6 +152,7 @@ syscall(void)
        p->syscall_counts[num]++;
        printf("%d: syscall %s(trace counts: %d) -> %d\n",
              p->pid, syscalls_name[num], p->syscall_counts[num], p->trapframe->a0);
+       printf("a1:%d a2:%d a3:%d\n",p->trapframe->a1,p->trapframe->a2,p->trapframe->a3);
     }
   } else {
     printf("%d %s: unknown sys call %d\n",