Move load_firmware() to separate file

The idea is to share loading code between bootloaders and rolo().

Change-Id: I1656ed91946d7a05cb7c9fa7a16793c3c862a5cd
Reviewed-on: http://gerrit.rockbox.org/190
Reviewed-by: Marcin Bukat <marcin.bukat@gmail.com>

firmware/common/loader_strerror.c

@@ -0,0 +1,63 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ *
+ * Copyright (C) 2013 Marcin Bukat
+ *
+ * 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 "loader_strerror.h"
+
+char *loader_strerror(enum error_t error)
+{
+    switch(error)
+    {
+    case EFILE_EMPTY:
+        return "File empty";
+    case EFILE_NOT_FOUND:
+        return "File not found";
+    case EREAD_CHKSUM_FAILED:
+        return "Read failed (chksum)";
+    case EREAD_MODEL_FAILED:
+        return "Read failed (model)";
+    case EREAD_IMAGE_FAILED:
+        return "Read failed (image)";
+    case EBAD_CHKSUM:
+        return "Bad checksum";
+    case EFILE_TOO_BIG:
+        return "File too big";
+    case EINVALID_FORMAT:
+        return "Invalid file format";
+#if defined(MI4_FORMAT)
+    case EREAD_HEADER_FAILED:
+        return "Can't read mi4 header";
+    case EKEY_NOT_FOUND:
+        return "Can't find crypt key";
+    case EDECRYPT_FAILED:
+        return "Decryption failed";
+#elif defined(RKW_FORMAT)
+    case EREAD_HEADER_FAILED:
+        return "Can't read RKW header";
+    case EBAD_HEADER_CHKSUM:
+        return "RKW header CRC error";
+    case EINVALID_LOAD_ADDR:
+        return "RKW Load address mismatch";
+    case EBAD_MODEL:
+        return "Bad model number";
+#endif
+    default:
+        return "Unknown error";
+    }
+}