brcm47xx: mtd: bcm47xxpart: detect block aligned Squashfs partition

Most of the bcm47xx devices use TRX format for storing kernel and some
partition like Squashfs or JFFS2. This is pretty flexible solution, CFE
(the bootloader) just writes (and later boots) TRX at some hardcoded
place and paritions can vary in the size.

However some devices don't use TRX format. Very recently we have
discovered ZTE H218N that has kernel and rootfs partitions at some
"random" places.

This patch allows Linux find a rootfs partition after installing custom
image with a CFE bootloader.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@37998 3c298f89-4303-0410-b956-a3cf2f4a3e73

diff --git a/target/linux/brcm47xx/patches-3.10/029-mtd-bcm47xxpart_detect_block_aligned_Squashfs_partition.patch b/target/linux/brcm47xx/patches-3.10/029-mtd-bcm47xxpart_detect_block_aligned_Squashfs_partition.patch
new file mode 100644 (file)
index 0000000..0efe16f
--- /dev/null
+++ b/target/linux/brcm47xx/patches-3.10/029-mtd-bcm47xxpart_detect_block_aligned_Squashfs_partition.patch
@@ -0,0 +1,40 @@
+mtd: bcm47xxpart: detect block aligned Squashfs partition
+
+Most of the bcm47xx devices use TRX format for storing kernel and some
+partition like Squashfs or JFFS2. This is pretty flexible solution, CFE
+(the bootloader) just writes (and later boots) TRX at some hardcoded
+place and paritions can vary in the size.
+
+However some devices don't use TRX format. Very recently we have
+discovered ZTE H218N that has kernel and rootfs partitions at some
+"random" places.
+
+This patch allows Linux find a rootfs partition after installing custom
+image with a CFE bootloader.
+
+Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
+
+--- a/drivers/mtd/bcm47xxpart.c
++++ b/drivers/mtd/bcm47xxpart.c
+@@ -33,6 +33,7 @@
+ #define ML_MAGIC1                     0x39685a42
+ #define ML_MAGIC2                     0x26594131
+ #define TRX_MAGIC                     0x30524448
++#define SQSH_MAGIC                    0x71736873      /* shsq */
+ 
+ struct trx_header {
+       uint32_t magic;
+@@ -170,6 +171,13 @@ static int bcm47xxpart_parse(struct mtd_
+                       offset = rounddown(offset + trx->length, blocksize);
+                       continue;
+               }
++
++              /* Squashfs on devices not using TRX */
++              if (buf[0x000 / 4] == SQSH_MAGIC) {
++                      bcm47xxpart_add_part(&parts[curr_part++], "rootfs",
++                                           offset, 0);
++                      continue;
++              }
+       }
+ 
+       /* Look for NVRAM at the end of the last block. */