xv6_add_syscall.diff

diff --git a/mkdir.c b/mkdir.c
index 6e4c954..f1a0a41 100644
--- a/mkdir.c
+++ b/mkdir.c
@@ -1,11 +1,13 @@
 #include "types.h"
 #include "stat.h"
+#include "date.h"
 #include "user.h"

 int
 main(int argc, char *argv[])
 {
   int i;
+  struct rtcdate rtc;

   if(argc < 2){
     printf(2, "Usage: mkdir files...\n");
@@ -19,5 +21,8 @@ main(int argc, char *argv[])
     }
   }

+  utc(&rtc);
+  printf(2, "time: %d\n", rtc.day);
+
   exit();
 }
diff --git a/syscall.c b/syscall.c
index ee85261..30e59cc 100644
--- a/syscall.c
+++ b/syscall.c
@@ -103,6 +103,7 @@ extern int sys_unlink(void);
 extern int sys_wait(void);
 extern int sys_write(void);
 extern int sys_uptime(void);
+extern int sys_utc(void);

 static int (*syscalls[])(void) = {
 [SYS_fork]    sys_fork,
@@ -126,6 +127,7 @@ static int (*syscalls[])(void) = {
 [SYS_link]    sys_link,
 [SYS_mkdir]   sys_mkdir,
 [SYS_close]   sys_close,
+[SYS_utc]     sys_utc,
 };

 void
diff --git a/syscall.h b/syscall.h
index bc5f356..9beb96f 100644
--- a/syscall.h
+++ b/syscall.h
@@ -20,3 +20,4 @@
 #define SYS_link   19
 #define SYS_mkdir  20
 #define SYS_close  21
+#define SYS_utc    22
diff --git a/sysfile.c b/sysfile.c
index 87e508b..be6942d 100644
--- a/sysfile.c
+++ b/sysfile.c
@@ -16,6 +16,8 @@
 #include "file.h"
 #include "fcntl.h"

+#include "date.h"
+
 // Fetch the nth word-sized system call argument as a file descriptor
 // and return both the descriptor and the corresponding struct file.
 static int
@@ -443,3 +445,12 @@ sys_pipe(void)
   fd[1] = fd1;
   return 0;
 }
+
+int sys_utc(void)
+{
+  struct rtcdate *rtc;
+  if(argptr(0, (void*)&rtc, sizeof(*rtc)) < 0)
+    return -1;
+  cmostime(rtc);
+  return 1;
+}
diff --git a/user.h b/user.h
index 4f99c52..42b7bd5 100644
--- a/user.h
+++ b/user.h
@@ -23,6 +23,7 @@ int getpid(void);
 char* sbrk(int);
 int sleep(int);
 int uptime(void);
+int utc(struct rtcdate*);

 // ulib.c
 int stat(const char*, struct stat*);
diff --git a/usys.S b/usys.S
index 8bfd8a1..d3dff42 100644
--- a/usys.S
+++ b/usys.S
@@ -29,3 +29,4 @@ SYSCALL(getpid)
 SYSCALL(sbrk)
 SYSCALL(sleep)
 SYSCALL(uptime)
+SYSCALL(utc)