I was tinkering with the GRUB last night and couldn't find a command to
cause a short delay or timeout of some sort. After looking through the
source, I wrote this small patch to add a delay and "echo" function.
After using it for a short time, I'm tempted to change it to a
countdown-style command with a prompt and a visible countdown like the
menu timeout, but I don't see any acceptably simple way to do it.
Matthias
diff -u -r1.100 builtins.c
--- grub/stage2/builtins.c 2000/12/17 19:25:50 1.100
+++ grub/stage2/builtins.c 2001/01/02 02:10:49
@@ -772,6 +772,41 @@
};
+/* delay */
+static int
+delay_func (char *arg, int flags)
+{
+ int delay_timeout, time1, time2 = -1;
+ if (! safe_parse_maxint (&arg, &delay_timeout))
+ return 1;
+
+ while ((time1 = getrtsecs()) == 0xFF);
+ while (1)
+ {
+ if (delay_timeout >= 0 && (time1 = getrtsecs()) != time2 && time1 != 0xFF)
+ {
+ if (delay_timeout <= 0)
+ {
+ delay_timeout = -1;
+ break;
+ }
+ delay_timeout--;
+ time2 = time1;
+ }
+ }
+ return 0;
+}
+
+static struct builtin builtin_delay =
+{
+ "delay",
+ delay_func,
+ BUILTIN_MENU|BUILTIN_CMDLINE,
+ "delay SEC",
+ "Pause for a timeout, in SEC seconds, before continuing."
+};
+
+
#ifdef GRUB_UTIL
/* device */
static int
@@ -930,6 +965,24 @@
};
+/* echo */
+static int
+echo_func (char *arg, int flags)
+{
+ grub_printf ("%s\n", arg);
+ return 0;
+}
+
+static struct builtin builtin_echo =
+{
+ "echo",
+ echo_func,
+ BUILTIN_CMDLINE|BUILTIN_MENU,
+ "echo [MESSAGE]",
+ "Print MESSAGE"
+};
+
+
static char embed_info[32];
/* embed */
/* Embed a Stage 1.5 in the first cylinder after MBR or in the
@@ -4085,6 +4138,7 @@
#endif /* SUPPORT_NETBOOT */
+
/* timeout */
static int
timeout_func (char *arg, int flags)
@@ -4309,6 +4363,7 @@
&builtin_configfile,
&builtin_debug,
&builtin_default,
+ &builtin_delay,
#ifdef GRUB_UTIL
&builtin_device,
#endif /* GRUB_UTIL */
@@ -4317,6 +4372,7 @@
#endif /* SUPPORT_NETBOOT */
&builtin_displayapm,
&builtin_displaymem,
+ &builtin_echo,
&builtin_embed,
&builtin_fallback,
&builtin_find,
