lantiq: handle the dual-firmware layout of brnboot

brnboot based devices can have two Image partitions. When flashing
images via the brnboot recovery web interface, the Image partitions are
written alternating.

The current active Image partition is stored in the first byte of the
Primary_Setting partition by using 0x00 for Code_Image_0 and 0x01 for
Code_Image_1.

By using the information about the active "Code Image", it is possible
to ensure that the rootfs belongs to the current booted Image/Kernel.

Signed-off-by: Mathias Kresin <openwrt@kresin.me>

SVN-Revision: 49281

1 files changed, 93 insertions, 0 deletions

diff --git a/target/linux/lantiq/patches-4.4/0101-find_active_root.patch b/target/linux/lantiq/patches-4.4/0101-find_active_root.patch
new file mode 100644
index 0000000..978def3
--- /dev/null
+++ b/target/linux/lantiq/patches-4.4/0101-find_active_root.patch
@@ -0,0 +1,93 @@
+--- a/drivers/mtd/ofpart.c
++++ b/drivers/mtd/ofpart.c
+@@ -25,6 +25,38 @@ static bool node_has_compatible(struct d
+ 	return of_get_property(pp, "compatible", NULL);
+ }
+ 
++static uint8_t * brnboot_get_selected_root_part(struct mtd_info *master,
++						loff_t offset)
++{
++	static uint8_t root_id;
++	int err, len;
++
++	err = mtd_read(master, offset, 0x01, &len, &root_id);
++
++	if (mtd_is_bitflip(err) || !err)
++		return &root_id;
++
++	return NULL;
++}
++
++static void brnboot_set_active_root_part(struct mtd_partition *pparts,
++					 struct device_node **part_nodes,
++					 int nr_parts,
++					 uint8_t *root_id)
++{
++	int i;
++
++	for (i = 0; i < nr_parts; i++) {
++		int part_root_id;
++
++		if (!of_property_read_u32(part_nodes[i], "brnboot,root-id", &part_root_id)
++		    && part_root_id == *root_id) {
++			pparts[i].name = "firmware";
++			break;
++		}
++	}
++}
++
+ static int parse_ofpart_partitions(struct mtd_info *master,
+ 				   struct mtd_partition **pparts,
+ 				   struct mtd_part_parser_data *data)
+@@ -35,7 +67,8 @@ static int parse_ofpart_partitions(struc
+ 	struct device_node *pp;
+ 	int nr_parts, i, ret = 0;
+ 	bool dedicated = true;
+-
++	uint8_t *proot_id = NULL;
++	struct device_node **part_nodes;
+ 
+ 	if (!data)
+ 		return 0;
+@@ -73,7 +106,9 @@ static int parse_ofpart_partitions(struc
+ 		return 0;
+ 
+ 	*pparts = kzalloc(nr_parts * sizeof(**pparts), GFP_KERNEL);
+-	if (!*pparts)
++	part_nodes = kzalloc(nr_parts * sizeof(*part_nodes), GFP_KERNEL);
++
++	if (!*pparts || !part_nodes)
+ 		return -ENOMEM;
+ 
+ 	i = 0;
+@@ -121,12 +156,22 @@ static int parse_ofpart_partitions(struc
+ 		if (of_get_property(pp, "lock", &len))
+ 			(*pparts)[i].mask_flags |= MTD_POWERUP_LOCK;
+ 
++		if (!proot_id && of_device_is_compatible(pp, "brnboot,root-selector"))
++			proot_id = brnboot_get_selected_root_part(master, (*pparts)[i].offset);
++
++		part_nodes[i] = pp;
++
+ 		i++;
+ 	}
+ 
+ 	if (!nr_parts)
+ 		goto ofpart_none;
+ 
++	if (proot_id)
++		brnboot_set_active_root_part(*pparts, part_nodes, nr_parts, proot_id);
++
++	kfree(part_nodes);
++
+ 	return nr_parts;
+ 
+ ofpart_fail:
+@@ -136,6 +181,7 @@ ofpart_fail:
+ ofpart_none:
+ 	of_node_put(pp);
+ 	kfree(*pparts);
++	kfree(part_nodes);
+ 	*pparts = NULL;
+ 	return ret;
+ }