Re: [PATCH -ac] Panicking in morse code v3

From: Andrew Rodland (arodland@noln.com)
Date: Sat Jul 20 2002 - 16:32:22 EST


Once more Mr. unnamed sent me some suggestions, and once more I've
merged [my own adaptation of] them in. Also, I took an attempt to make
it somewhat more platform-independent, and re-organize. The original
panic_blink was in pc_keyb.c, and was guarded by an #ifdef __i386__ .
v3 moves the generic code out of pc_keyb (and into panic.c). It should
be able to blink on anything that uses pc_keyb (i386, some ARM, and
some MIPS, apparently), and should be able to beep on anything that
defines kd_mksound to do something (currently only i386). Also the code
has been reorganized so as to be easier to read and follow, and there
are a few more punctuation characters.

Yes, I actually _am_ trying to turn this into something useful.
Now, I don't have a 2.5 tree, and probably wouldn't understand it if I
did, but I get a feeling that this won't be so incredibly easy to port,
thanks to having everything use the input layer. Or am I wrong?

--hobbs

Patch follows

diff -u -r linux.old/drivers/char/pc_keyb.c linux.new/drivers/char/pc_keyb.c
--- linux.old/drivers/char/pc_keyb.c Fri Jul 19 18:56:36 2002
+++ linux.new/drivers/char/pc_keyb.c Sat Jul 20 13:18:40 2002
@@ -1244,41 +1244,13 @@
 #endif /* CONFIG_PSMOUSE */
 
 
-static int blink_frequency = HZ/2;
+void pckbd_blink (char led) {
+ led = led ? (0x01 | 0x04) : 0x00;
 
-/* Tell the user who may be running in X and not see the console that we have
- panic'ed. This is to distingush panics from "real" lockups.
- Could in theory send the panic message as morse, but that is left as an
- exercise for the reader. */
-void panic_blink(void)
-{
- static unsigned long last_jiffie;
- static char led;
- /* Roughly 1/2s frequency. KDB uses about 1s. Make sure it is
- different. */
- if (!blink_frequency)
- return;
- if (jiffies - last_jiffie > blink_frequency) {
- led ^= 0x01 | 0x04;
                 while (kbd_read_status() & KBD_STAT_IBF) mdelay(1);
                 kbd_write_output(KBD_CMD_SET_LEDS);
                 mdelay(1);
                 while (kbd_read_status() & KBD_STAT_IBF) mdelay(1);
                 mdelay(1);
                 kbd_write_output(led);
- last_jiffie = jiffies;
- }
-}
-
-static int __init panicblink_setup(char *str)
-{
- int par;
- if (get_option(&str,&par))
- blink_frequency = par*(1000/HZ);
- return 1;
 }
-
-/* panicblink=0 disables the blinking as it caused problems with some console
- switches. otherwise argument is ms of a blink period. */
-__setup("panicblink=", panicblink_setup);
-
diff -u -r linux.old/kernel/panic.c linux.new/kernel/panic.c
--- linux.old/kernel/panic.c Fri Jul 19 18:56:36 2002
+++ linux.new/kernel/panic.c Sat Jul 20 17:28:41 2002
@@ -16,6 +16,8 @@
 #include <linux/init.h>
 #include <linux/sysrq.h>
 #include <linux/interrupt.h>
+#include <linux/vt_kern.h>
+#include <linux/pc_keyb.h>
 
 asmlinkage void sys_sync(void); /* it's really int */
 
@@ -28,9 +30,132 @@
         panic_timeout = simple_strtoul(str, NULL, 0);
         return 1;
 }
-
 __setup("panic=", panic_setup);
 
+static int blink_setting = 1;
+
+/* Tell the user who may be running in X and not see the console that we have
+ panic'ed. This is to distingush panics from "real" lockups.
+ Could in theory send the panic message as morse, but that is left as an
+ exercise for the reader.
+ And now it's done! LED and speaker morse code by Andrew Rodland
+ <arodland@noln.com>, with improvements based on suggestions from
+ linux@horizon.com.
+*/
+
+static const unsigned char morsetable[] = {
+ /* ! " # $ % & ' */
+ 0, 0122, 0, 0310, 0, 0, 0163,
+ /* ( ) * + , - . / */
+ 055, 0155, 0, 0, 0163, 0141, 0152, 0051,
+ /* 0-9 */
+ 077, 076, 074, 070, 060, 040, 041, 043, 047, 057,
+ /* : ; < = > ? @ */
+ 0107, 0125, 0, 0061, 0, 0114, 0,
+ /* A-I */
+ 006, 021, 025, 011, 002, 024, 013, 020, 004,
+ /* J-R */
+ 036, 015, 022, 007, 005, 017, 026, 033, 012,
+ /* S-Z */
+ 010, 003, 014, 030, 016, 031, 035, 023,
+ /* [ \ ] ^ */
+ 0, 0, 0, 0,
+ /* _ */
+ 0154
+
+};
+
+#define DITLEN (HZ / 5)
+#define DAHLEN 3 * DITLEN
+#define SPACELEN 7 * DITLEN
+
+#define FREQ 844
+
+
+#if (defined(__i386__) && defined(CONFIG_VT)) || defined(CONFIG_PC_KEYB)
+#define do_blink(x) pckbd_blink(x)
+#else
+#define do_blink(x) 0
+#endif
+
+void panic_blink(char * buf)
+{
+ static unsigned long next_jiffie = 0;
+ static char * bufpos = 0;
+ static unsigned char morse = 0;
+ static char state = 1;
+
+ if (!blink_setting)
+ return;
+
+ if (!buf)
+ buf="Panic lost?";
+
+
+ if (bufpos && time_after (next_jiffie, jiffies)) {
+ return; /* Waiting for something. */
+ }
+
+ if (state) { /* Coming off of a blink. */
+ if (blink_setting & 0x01)
+ do_blink(0);
+
+ state = 0;
+
+ if(morse > 1) { /* Not done yet, just a one-dit pause. */
+ next_jiffie = jiffies + DITLEN;
+ } else { /* Get a new char, and figure out how much space. */
+
+ if(!bufpos)
+ bufpos = (char *)buf; /* First time through */
+
+ if(!*bufpos) {
+ bufpos = (char *)buf; /* Repeating */
+ next_jiffie = jiffies + SPACELEN;
+ } else {
+ next_jiffie = jiffies + DAHLEN; /* Inter-letter space */
+ }
+
+ if (*bufpos >= '!' && *bufpos <= '_') {
+ morse = morsetable[*bufpos - '!'];
+ } else if (*bufpos >= 'a' && *bufpos <= 'z') {
+ morse = morsetable[*bufpos - 'a' + 'A' - '!'];
+ } else {
+ next_jiffie = jiffies + SPACELEN; /*Space -- For a total of 7*/
+ state = 1; /* And bring us back here when we're done */
+ }
+ bufpos ++;
+ }
+ } else { /* Starting a new blink. We have valid code in morse. */
+ int len;
+
+ len = (morse & 001) ? DAHLEN : DITLEN;
+
+ if (blink_setting & 0x02)
+ kd_mksound(FREQ, len);
+
+ next_jiffie = jiffies + len;
+
+ if (blink_setting & 0x01)
+ do_blink(1);
+ state = 1;
+ morse >>= 1;
+ }
+}
+
+static int __init panicblink_setup(char *str)
+{
+ int par;
+ if (get_option(&str,&par))
+ blink_setting = par;
+ return 1;
+}
+
+/* panicblink=0 disables the blinking as it caused problems with some console
+ switches. otherwise argument is ms of a blink period. */
+__setup("panicblink=", panicblink_setup);
+
+
 /**
  * panic - halt the system
  * @fmt: The text string to print
@@ -96,10 +221,7 @@
 #endif
         sti();
         for(;;) {
-#if defined(__i386__) && defined(CONFIG_VT)
- extern void panic_blink(void);
- panic_blink();
-#endif
+ panic_blink(buf);
                 CHECK_EMERGENCY_SYNC
         }
 }

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This archive was generated by hypermail 2b29 : Tue Jul 23 2002 - 22:00:34 EST