From 25e50ed8f1361ef3295aeb298a3edf2214f5b3b3 Mon Sep 17 00:00:00 2001
From: Frank Gevaerts <frank@gevaerts.be>
Date: Sun, 5 Jan 2014 22:20:26 +0100
Subject: [PATCH] Print `last logf lines on panic().

If logf is enabled, panic() will print the last lines. On small
screens this is more or less useless, but on large screens it
can be very useful for debugging.

Change-Id: I26dfc76e9ac4a2ddc2def8db1616a04f943dbba3
Reviewed-on: http://gerrit.rockbox.org/709
Reviewed-by: Thomas Martitz <kugel@rockbox.org>
Reviewed-by: Frank Gevaerts <frank@gevaerts.be>
Tested: Frank Gevaerts <frank@gevaerts.be>
---
 firmware/export/logf.h |  2 ++
 firmware/logf.c        | 49 ++++++++++++++++++++++++++++++++++++++++++
 firmware/panic.c       |  4 ++++
 3 files changed, 55 insertions(+)

diff --git a/firmware/export/logf.h b/firmware/export/logf.h
index b57ae91872..e881e7e496 100644
--- a/firmware/export/logf.h
+++ b/firmware/export/logf.h
@@ -39,6 +39,8 @@ extern bool logfwrap;
 #define logf _logf
 void _logf(const char *format, ...) ATTRIBUTE_PRINTF(1, 2);
 
+void logf_panic_dump(int *y);
+
 #else /* !ROCKBOX_HAS_LOGF */
 
 /* built without logf() support enabled, replace logf() by DEBUGF() */
diff --git a/firmware/logf.c b/firmware/logf.c
index fadfc9bb13..a24a635570 100644
--- a/firmware/logf.c
+++ b/firmware/logf.c
@@ -32,6 +32,7 @@
 #include "config.h"
 #include "system.h"
 #include "font.h"
+#include "lcd.h"
 #ifdef HAVE_REMOTE_LCD
 #include "lcd-remote.h"
 #endif
@@ -254,6 +255,54 @@ void _logf(const char *fmt, ...)
 }
 #endif
 
+void logf_panic_dump(int *y)
+{
+    int i;
+    /* nothing to print ? */
+    if(logfindex == 0 && !logfwrap)
+    {
+        lcd_puts(1, (*y)++, "no logf data");
+        lcd_update();
+        return;
+    }
+
+    lcd_puts(1, (*y)++, "start of logf data");
+    lcd_update();
+    i = logfindex - 2; /* The last actual characer (i.e. not '\0') */
+
+    while(i >= 0)
+    {
+        while(logfbuffer[i] != 0 && i>=0)
+        {
+            i--;
+        }
+        if(strlen( &logfbuffer[i + 1]) > 0)
+        {
+            lcd_puts(1, (*y)++, &logfbuffer[i + 1]);
+            lcd_update();
+        }
+        i--;
+    }
+    if(logfwrap)
+    {
+        i = MAX_LOGF_SIZE - 1;
+        while(i >= logfindex)
+        {
+            while(logfbuffer[i] != 0 && i >= logfindex)
+            {
+                i--;
+            }
+            if(strlen( &logfbuffer[i + 1]) > 0)
+            {
+                lcd_putsf(1, (*y)++, "%*s", (MAX_LOGF_SIZE-i) &logfbuffer[i + 1]);
+                lcd_update();
+            }
+        }
+        i--;
+    }
+    lcd_puts(1, (*y)++, "end of logf data");
+    lcd_update();
+}
 #endif
 
 #ifdef ROCKBOX_HAS_LOGDISKF
diff --git a/firmware/panic.c b/firmware/panic.c
index 0d49847a19..3f01689922 100644
--- a/firmware/panic.c
+++ b/firmware/panic.c
@@ -30,6 +30,7 @@
 #include "led.h"
 #include "power.h"
 #include "system.h"
+#include "logf.h"
 
 #if defined(CPU_ARM)
 #include "gcc_extensions.h"
@@ -115,6 +116,9 @@ void panicf( const char *fmt, ...)
 #if defined(CPU_ARM)
     backtrace(pc, sp, &y);
 #endif
+#ifdef ROCKBOX_HAS_LOGF
+    logf_panic_dump(&y);
+#endif
 #else
     /* no LCD */
 #endif