Add RKW firmware file format loader

Change-Id: I5283fdcdb8d263fd9375a6d29396f82650aeb686

firmware/target/arm/rk27xx/rkw-loader.c

@@ -0,0 +1,149 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ *
+ * Copyright (C) 2012 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 1
+ * 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 "config.h"
+#include "rkw.h"
+#include "crc32-rkw.h"
+#include "file.h"
+#include "panic.h"
+
+/* error strings sorted by number */
+/* error 0 is empty */
+static const char *err_str[] = {
+    "Loading OK",
+    "Can't open RKW file",
+    "Can't read RKW header",
+    "Invalid RKW magic number",
+    "RKW header CRC error",
+    "RKW file too big",
+    "RKW Load address mismatch",
+    "Bad model number",
+    "Error Reading File",
+    "RKW firmware CRC error"
+};
+
+const char *rkw_strerror(int8_t errno)
+{
+    if (-errno >= sizeof(err_str)/sizeof(err_str[0]) || errno > 0)
+        return "Unknown error";
+
+    return err_str[-errno];
+}
+
+/* loosely based on load_firmware()
+ * on success we return size loaded image
+ * on error we return negative value which can be deciphered by means
+ * of rkw_strerror() function
+ */
+int load_rkw(unsigned char* buf, const char* filename, int buffer_size)
+{
+    int fd;
+    int rc;
+    int len;
+    int ret;
+    uint32_t crc, fw_crc;
+    struct rkw_header_t rkw_info;
+
+    fd = open(filename, O_RDONLY);
+
+    if(fd < 0)
+        return -1;
+
+    rc = read(fd, &rkw_info, sizeof(rkw_info));
+    if (rc < (int)sizeof(rkw_info))
+    {
+        ret = -2;
+        goto end;
+    }
+
+    /* check if RKW is valid */
+    if (rkw_info.magic_number != RKLD_MAGIC)
+    {
+        ret = -3;
+        goto end;
+    }
+
+    /* check header crc if present */
+    if (rkw_info.load_options & RKW_HEADER_CRC)
+    {
+        crc = crc32_rkw((uint8_t *)&rkw_info, sizeof(rkw_info)-sizeof(uint32_t));
+        if (rkw_info.crc != crc)
+        {
+            ret = -4;
+            goto end;
+        }
+    }
+
+    /* check image size */
+    len = rkw_info.load_limit - rkw_info.load_address;
+    if (len > buffer_size)
+    {
+        ret = -5;
+        goto end;
+    }
+
+    /* check load address - we support loading only at 0x60000000 */
+    if (rkw_info.load_address != 0x60000000)
+    {
+        ret = -6;
+        goto end;
+    }
+
+    /* rockbox extension - we use one of reserved fields to store
+     * model number information. This prevents from loading
+     * rockbox RKW for different player.
+     */
+    if (rkw_info.reserved0 != 0 && rkw_info.reserved0 != MODEL_NUMBER)
+    {
+        ret = -7;
+        goto end;
+    }
+
+    /* skip header */
+    lseek(fd, sizeof(rkw_info), SEEK_SET);
+
+    /* load image into buffer */
+    rc = read(fd, buf, len);
+
+    if(rc < len)
+    {
+        ret = -8;
+        goto end;
+    }
+
+    if (rkw_info.load_options & RKW_IMAGE_CRC)
+    {
+        rc = read(fd, &fw_crc, sizeof(uint32_t));
+
+        crc = crc32_rkw((uint8_t *)buf, len);
+
+        if (fw_crc != crc)
+        {
+            ret = -9;
+            goto end;
+        }
+    }
+
+    ret = len;
+end:
+    close(fd);
+    return ret;
+}
+