initial logf() work, not added to SOURCES yet (on purpose)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@6514 a1c6a512-1295-4272-9138-f99709370657

firmware/export/logf.h

@@ -0,0 +1,29 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2005 by Daniel Stenberg
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef LOGF_H
+#define LOGF_H
+
+extern unsigned char logfbuffer[];
+extern unsigned char *logfptr;
+extern unsigned char *logfend;
+extern bool logfwrap;
+
+void logf(const char *format, ...);
+
+#endif /* LOGF_H */

firmware/logf.c

@@ -0,0 +1,60 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2005 by Daniel Stenberg
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+/*
+ * logf() logs 16 bytes in a circular buffer. Each logged string is space-
+ * padded for easier and faster output on screen. Just output 16 lines on each
+ * line. 16 bytes fit nicely on the iRiver remote LCD (128 pixels with an 8
+ * pixels font).
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <sprintf.h>
+#include <stdbool.h>
+#include "config.h"
+
+#define MAX_LOGF_LINES 1000
+#define MAX_LOGF_DATASIZE (16*MAX_LOGF_LINES)
+
+unsigned char logfbuffer[MAX_LOGF_DATASIZE];
+unsigned char *logfend=&logfbuffer[MAX_LOGF_DATASIZE];
+unsigned char *logfptr=&logfbuffer[0];
+bool logfwrap;
+
+void logf(const char *format, ...)
+{
+    int len;
+    va_list ap;
+    va_start(ap, format);
+
+    if(logfptr >= logfend) {
+        /* wrap */
+        logfwrap = true;
+        logfptr = &logfbuffer[0];
+    }
+    len = vsnprintf(logfptr, 16, format, ap);
+    va_end(ap);
+    if(len < 16)
+        /* pad with spaces up to the 16 byte border */
+        memset(logfptr+len, ' ', 16-len);
+
+    logfptr += 16; /* leave it where we write the next time */
+}