Add ramdisk storage driver. It will be useful for developing multi-driver storage

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@18993 a1c6a512-1295-4272-9138-f99709370657

firmware/drivers/ramdisk.c

@@ -0,0 +1,102 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id: ramdisk.c 18965 2008-11-01 17:33:21Z gevaerts $
+ *
+ * Copyright (C) 2008 Frank Gevaerts
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include <stdbool.h>
+#include <string.h>
+
+#include "storage.h"
+
+#define SECTOR_SIZE 512
+#define NUM_SECTORS 16384
+
+extern unsigned char ramdisk[SECTOR_SIZE * NUM_SECTORS];
+
+long last_disk_activity = -1;
+
+int ramdisk_read_sectors(IF_MV2(int drive,)
+                     unsigned long start,
+                     int count,
+                     void* buf)
+{
+    if(start+count>=NUM_SECTORS)
+    {
+        return -1;
+    }
+    memcpy(buf,&ramdisk[start*SECTOR_SIZE],count*SECTOR_SIZE);
+    return 0;
+}
+
+int ramdisk_write_sectors(IF_MV2(int drive,)
+                      unsigned long start,
+                      int count,
+                      const void* buf)
+{
+    if(start+count>=NUM_SECTORS)
+    {
+        return -1;
+    }
+    memcpy(&ramdisk[start*SECTOR_SIZE],buf,count*SECTOR_SIZE);
+    return 0;
+}
+
+int ramdisk_init(void)
+{
+    return 0;
+}
+
+long ramdisk_last_disk_activity(void)
+{
+    return last_disk_activity;
+}
+
+void ramdisk_sleep(void)
+{
+}
+
+void ramdisk_spin(void)
+{
+}
+
+void ramdisk_sleepnow(void)
+{
+}
+
+void ramdisk_spindown(int seconds)
+{
+    (void)seconds;
+}
+#ifdef STORAGE_GET_INFO
+void ramdisk_get_info(struct storage_info *info)
+{
+    /* firmware version */
+    info->revision="0.00";
+
+    /* vendor field, need better name? */
+    info->vendor="Rockbox";
+    /* model field, need better name? */
+    info->product="Ramdisk";
+
+    /* blocks count */
+    info->num_sectors=NUM_SECTORS;
+    info->sector_size=SECTOR_SIZE;
+}
+#endif
+