Index: apps/main.c
===================================================================
--- apps/main.c
+++ apps/main.c
@@ -116,6 +116,12 @@
 #include "system-sdl.h"
 #endif
 
+// #define LOGF_ENABLE
+
+#ifdef LOGF_ENABLE
+#include "logf.h"
+#endif
+
 /*#define AUTOROCK*/ /* define this to check for "autostart.rock" on boot */
 
 const char appsversion[]=APPSVERSION;
@@ -378,6 +384,9 @@ static void init(void)
 #ifdef CPU_ARM
     enable_fiq();
 #endif
+#ifdef LOGF_ENABLE
+    logf_file_open(LOGF_FILENAME);
+#endif
     lcd_init();
 #ifdef HAVE_REMOTE_LCD
     lcd_remote_init();
index: apps/misc.c
===================================================================
--- apps/misc.c
+++ apps/misc.c
@@ -90,6 +90,12 @@
 #endif
 #endif
 
+// #define LOGF_ENABLE
+
+#ifdef LOGF_ENABLE
+#include "logf.h"
+#endif
+
 /* Format a large-range value for output, using the appropriate unit so that
  * the displayed value is in the range 1 <= display < 1000 (1024 for "binary"
  * units) if possible, and 3 significant digits are shown. If a buffer is
@@ -394,6 +400,9 @@ static bool clean_shutdown(void (*callback)(void *), void *parameter)
             dircache_disable();
 #endif
 
+#ifdef LOGF_ENABLE
+    logf_file_close();
+#endif
         shutdown_hw();
     }
 #endif
Index: apps/settings.h
===================================================================
--- apps/settings.h
+++ apps/settings.h
@@ -79,6 +79,7 @@ struct opt_items {
 #define VIEWERS_CONFIG      ROCKBOX_DIR "/viewers.config"
 #define CONFIGFILE          ROCKBOX_DIR "/config.cfg"
 #define FIXEDSETTINGSFILE   ROCKBOX_DIR "/fixed.cfg"
+#define LOGF_FILENAME       ROCKBOX_DIR "/logf.log"
 
 #define MAX_FILENAME 32
 
Index: firmware/export/logf.h
===================================================================
--- firmware/export/logf.h
+++ firmware/export/logf.h
@@ -39,6 +39,10 @@
 extern unsigned char logfbuffer[MAX_LOGF_LINES][MAX_LOGF_ENTRY+1];
 extern int logfindex;
 extern bool logfwrap;
+
+int logf_file_open(const char* fname);
+void logf_file_close(void);
+void logf_puts(char* s);
 #endif /* __PCTOOL__ */
 
 #define logf _logf
Index: firmware/logf.c
===================================================================
--- firmware/logf.c
+++ firmware/logf.c
@@ -55,6 +55,9 @@
 /* Only provide all this if asked to */
 #ifdef ROCKBOX_HAS_LOGF
 
+static int logf_id = -1;
+static char logf_path[512];
+
 #ifndef __PCTOOL__
 unsigned char logfbuffer[MAX_LOGF_LINES][MAX_LOGF_ENTRY+1];
 int logfindex;
@@ -131,6 +134,8 @@ void _logf(const char *format, ...)
     va_end(ap);
 
     len = strlen(buf);
+    logf_puts(buf);
+
 #ifdef HAVE_SERIAL
     serial_tx(buf);
     serial_tx("\r\n");
@@ -165,6 +170,44 @@ void _logf(const char *format, ...)
 
     displayremote();
 }
+
+int logf_file_open(const char *fname)
+{
+    if (logf_id < 0)
+    {
+        if (fname != logf_path)
+            strcpy(logf_path, fname);
+        logf_id = open(logf_path, O_WRONLY | O_CREAT | O_APPEND);
+
+         if(logf_id >= 0)
+             logf("logf file %s open.", fname);
+    }
+
+    return 0;
+}
+
+void logf_file_close(void)
+{
+    if(logf_id >= 0)
+    {
+        logf_puts("testing_end");
+        close(logf_id);
+        logf_id = -1;
+    }
+}
+
+void logf_puts(char *s)
+{
+     if (logf_id < 0)
+         logf_file_open(logf_path);
+
+     if (logf_id >= 0)
+     {
+          write(logf_id, s, strlen(s));
+          write(logf_id, "\n", 1);
+     }
+}
+
 #endif
 
 #endif