Make ar7_part more readable and endianness safe

[openwrt.git] / target / linux / ar7 / files / drivers / mtd / ar7part.c

diff --git a/target/linux/ar7/files/drivers/mtd/ar7part.c b/target/linux/ar7/files/drivers/mtd/ar7part.c
index 1111575..8bfd571 100644 (file)
--- a/target/linux/ar7/files/drivers/mtd/ar7part.c
+++ b/target/linux/ar7/files/drivers/mtd/ar7part.c
@@ -1,16 +1,16 @@
 /*
  * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
- * 
+ *
  * 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 program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
@@ -26,7 +26,18 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
 #include <linux/bootmem.h>
-#include <linux/squashfs_fs.h>
+#include <linux/magic.h>
+
+#define AR7_PARTS      4
+#define ROOT_OFFSET    0xe0000
+
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+#define LOADER_MAGIC1  0xfeedfa42
+#define LOADER_MAGIC2  0xfeed1281
+#else
+#define LOADER_MAGIC1  0x42faedfe
+#define LOADER_MAGIC2  0x8112edfe
+#endif
 
 struct ar7_bin_rec {
        unsigned int checksum;
@@ -34,21 +45,19 @@ struct ar7_bin_rec {
        unsigned int address;
 };
 
-static struct mtd_partition ar7_parts[5];
+static struct mtd_partition ar7_parts[AR7_PARTS];
 
-static int create_mtd_partitions(struct mtd_info *master, 
-                                struct mtd_partition **pparts, 
+static int create_mtd_partitions(struct mtd_info *master,
+                                struct mtd_partition **pparts,
                                 unsigned long origin)
 {
        struct ar7_bin_rec header;
        unsigned int offset, len;
        unsigned int pre_size = master->erasesize, post_size = 0;
-       unsigned int root_offset = 0xe0000;
+       unsigned int root_offset = ROOT_OFFSET;
 
        int retries = 10;
 
-       printk(KERN_INFO "Parsing AR7 partition map...\n");
-
        ar7_parts[0].name = "loader";
        ar7_parts[0].offset = 0;
        ar7_parts[0].size = master->erasesize;
@@ -59,14 +68,15 @@ static int create_mtd_partitions(struct mtd_info *master,
        ar7_parts[1].size = master->erasesize;
        ar7_parts[1].mask_flags = 0;
 
-       do {
+       do { /* Try 10 blocks starting from master->erasesize */
                offset = pre_size;
-               master->read(master, offset, sizeof(header), &len, (u_char *)&header);
+               master->read(master, offset,
+                       sizeof(header), &len, (u_char *)&header);
                if (!strncmp((char *)&header, "TIENV0.8", 8))
                        ar7_parts[1].offset = pre_size;
-               if (header.checksum == 0xfeedfa42)
+               if (header.checksum == LOADER_MAGIC1)
                        break;
-               if (header.checksum == 0xfeed1281)
+               if (header.checksum == LOADER_MAGIC2)
                        break;
                pre_size += master->erasesize;
        } while (retries--);
@@ -79,19 +89,19 @@ static int create_mtd_partitions(struct mtd_info *master,
        }
 
        switch (header.checksum) {
-       case 0xfeedfa42:
+       case LOADER_MAGIC1:
                while (header.length) {
                        offset += sizeof(header) + header.length;
                        master->read(master, offset, sizeof(header),
-                                    &len, (u_char *)&header); 
+                                    &len, (u_char *)&header);
                }
                root_offset = offset + sizeof(header) + 4;
                break;
-       case 0xfeed1281:
+       case LOADER_MAGIC2:
                while (header.length) {
                        offset += sizeof(header) + header.length;
                        master->read(master, offset, sizeof(header),
-                                    &len, (u_char *)&header); 
+                                    &len, (u_char *)&header);
                }
                root_offset = offset + sizeof(header) + 4 + 0xff;
                root_offset &= ~(u32)0xff;
@@ -101,7 +111,8 @@ static int create_mtd_partitions(struct mtd_info *master,
                break;
        }
 
-       master->read(master, root_offset, sizeof(header), &len, (u_char *)&header);
+       master->read(master, root_offset,
+               sizeof(header), &len, (u_char *)&header);
        if (header.checksum != SQUASHFS_MAGIC) {
                root_offset += master->erasesize - 1;
                root_offset &= ~(master->erasesize - 1);
@@ -118,7 +129,7 @@ static int create_mtd_partitions(struct mtd_info *master,
        ar7_parts[3].mask_flags = 0;
 
        *pparts = ar7_parts;
-       return 4;
+       return AR7_PARTS;
 }
 
 static struct mtd_part_parser ar7_parser = {
@@ -135,5 +146,6 @@ static int __init ar7_parser_init(void)
 module_init(ar7_parser_init);
 
 MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>, Eugene Konev <ejka@openwrt.org>");
+MODULE_AUTHOR( "Felix Fietkau <nbd@openwrt.org>, "
+               "Eugene Konev <ejka@openwrt.org>");
 MODULE_DESCRIPTION("MTD partitioning for TI AR7");