openwrtv3/target/linux/generic/patches-3.12/400-mtd-add-rootfs-split-support.patch
Gabor Juhos 5dba0a237e kernel/3.1[02]: move MTD root device setup code to mtdcore
The current code only allows to automatically set
root device on MTD partitions. Move the code to MTD
core to allow to use it with all MTD devices.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

SVN-Revision: 38643
2013-11-04 18:37:05 +00:00

285 lines
7.2 KiB
Diff

--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -12,6 +12,32 @@ menuconfig MTD
if MTD
+menu "OpenWrt specific MTD options"
+
+config MTD_ROOTFS_ROOT_DEV
+ bool "Automatically set 'rootfs' partition to be root filesystem"
+ default y
+
+config MTD_ROOTFS_SPLIT
+ bool "Automatically split 'rootfs' partition for squashfs"
+ default y
+
+config MTD_SPLIT_FIRMWARE
+ bool "Automatically split firmware partition for kernel+rootfs"
+ default y
+
+config MTD_SPLIT_FIRMWARE_NAME
+ string "Firmware partition name"
+ depends on MTD_SPLIT_FIRMWARE
+ default "firmware"
+
+config MTD_UIMAGE_SPLIT
+ bool "Enable split support for firmware partitions containing a uImage"
+ depends on MTD_SPLIT_FIRMWARE
+ default y
+
+endmenu
+
config MTD_TESTS
tristate "MTD tests support (DANGEROUS)"
depends on m
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -29,6 +29,7 @@
#include <linux/kmod.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
+#include <linux/magic.h>
#include <linux/err.h>
#include "mtdcore.h"
@@ -45,13 +46,14 @@ struct mtd_part {
struct list_head list;
};
+static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part);
+
/*
* Given a pointer to the MTD object in the mtd_part structure, we can retrieve
* the pointer to that structure with this macro.
*/
#define PART(x) ((struct mtd_part *)(x))
-
/*
* MTD methods which simply translate the effective address and pass through
* to the _real_ device.
@@ -534,8 +536,10 @@ out_register:
return slave;
}
-int mtd_add_partition(struct mtd_info *master, char *name,
- long long offset, long long length)
+
+static int
+__mtd_add_partition(struct mtd_info *master, char *name,
+ long long offset, long long length, bool dup_check)
{
struct mtd_partition part;
struct mtd_part *p, *new;
@@ -567,21 +571,24 @@ int mtd_add_partition(struct mtd_info *m
end = offset + length;
mutex_lock(&mtd_partitions_mutex);
- list_for_each_entry(p, &mtd_partitions, list)
- if (p->master == master) {
- if ((start >= p->offset) &&
- (start < (p->offset + p->mtd.size)))
- goto err_inv;
-
- if ((end >= p->offset) &&
- (end < (p->offset + p->mtd.size)))
- goto err_inv;
- }
+ if (dup_check) {
+ list_for_each_entry(p, &mtd_partitions, list)
+ if (p->master == master) {
+ if ((start >= p->offset) &&
+ (start < (p->offset + p->mtd.size)))
+ goto err_inv;
+
+ if ((end >= p->offset) &&
+ (end < (p->offset + p->mtd.size)))
+ goto err_inv;
+ }
+ }
list_add(&new->list, &mtd_partitions);
mutex_unlock(&mtd_partitions_mutex);
add_mtd_device(&new->mtd);
+ mtd_partition_split(master, new);
return ret;
err_inv:
@@ -591,6 +598,12 @@ err_inv:
}
EXPORT_SYMBOL_GPL(mtd_add_partition);
+int mtd_add_partition(struct mtd_info *master, char *name,
+ long long offset, long long length)
+{
+ return __mtd_add_partition(master, name, offset, length, true);
+}
+
int mtd_del_partition(struct mtd_info *master, int partno)
{
struct mtd_part *slave, *next;
@@ -614,6 +627,144 @@ int mtd_del_partition(struct mtd_info *m
}
EXPORT_SYMBOL_GPL(mtd_del_partition);
+static inline unsigned long
+mtd_pad_erasesize(struct mtd_info *mtd, int offset, int len)
+{
+ unsigned long mask = mtd->erasesize - 1;
+
+ len += offset & mask;
+ len = (len + mask) & ~mask;
+ len -= offset & mask;
+ return len;
+}
+
+#define ROOTFS_SPLIT_NAME "rootfs_data"
+
+struct squashfs_super_block {
+ __le32 s_magic;
+ __le32 pad0[9];
+ __le64 bytes_used;
+};
+
+
+static int split_squashfs(struct mtd_info *master, int offset, int *split_offset)
+{
+ struct squashfs_super_block sb;
+ int len, ret;
+
+ ret = mtd_read(master, offset, sizeof(sb), &len, (void *) &sb);
+ if (ret || (len != sizeof(sb))) {
+ printk(KERN_ALERT "split_squashfs: error occured while reading "
+ "from \"%s\"\n", master->name);
+ return -EINVAL;
+ }
+
+ if (SQUASHFS_MAGIC != le32_to_cpu(sb.s_magic) ) {
+ printk(KERN_ALERT "split_squashfs: no squashfs found in \"%s\"\n",
+ master->name);
+ *split_offset = 0;
+ return 0;
+ }
+
+ if (le64_to_cpu((sb.bytes_used)) <= 0) {
+ printk(KERN_ALERT "split_squashfs: squashfs is empty in \"%s\"\n",
+ master->name);
+ *split_offset = 0;
+ return 0;
+ }
+
+ len = (u32) le64_to_cpu(sb.bytes_used);
+ len = mtd_pad_erasesize(master, offset, len);
+ *split_offset = offset + len;
+
+ return 0;
+}
+
+static void split_rootfs_data(struct mtd_info *master, struct mtd_part *part)
+{
+ unsigned int split_offset = 0;
+ unsigned int split_size;
+ int ret;
+
+ ret = split_squashfs(master, part->offset, &split_offset);
+ if (ret)
+ return;
+
+ if (split_offset <= 0)
+ return;
+
+ split_size = part->mtd.size - (split_offset - part->offset);
+ printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=0x%x, len=0x%x\n",
+ ROOTFS_SPLIT_NAME, split_offset, split_size);
+
+ __mtd_add_partition(master, ROOTFS_SPLIT_NAME, split_offset,
+ split_size, false);
+}
+
+#define UBOOT_MAGIC 0x27051956
+
+static void split_uimage(struct mtd_info *master, struct mtd_part *part)
+{
+ struct {
+ __be32 magic;
+ __be32 pad[2];
+ __be32 size;
+ } hdr;
+ size_t len;
+
+ if (mtd_read(master, part->offset, sizeof(hdr), &len, (void *) &hdr))
+ return;
+
+ if (len != sizeof(hdr) || hdr.magic != cpu_to_be32(UBOOT_MAGIC))
+ return;
+
+ len = be32_to_cpu(hdr.size) + 0x40;
+ len = mtd_pad_erasesize(master, part->offset, len);
+ if (len + master->erasesize > part->mtd.size)
+ return;
+
+ __mtd_add_partition(master, "rootfs", part->offset + len,
+ part->mtd.size - len, false);
+}
+
+#ifdef CONFIG_MTD_SPLIT_FIRMWARE_NAME
+#define SPLIT_FIRMWARE_NAME CONFIG_MTD_SPLIT_FIRMWARE_NAME
+#else
+#define SPLIT_FIRMWARE_NAME "unused"
+#endif
+
+static void split_firmware(struct mtd_info *master, struct mtd_part *part)
+{
+ if (config_enabled(CONFIG_MTD_UIMAGE_SPLIT))
+ split_uimage(master, part);
+}
+
+void __weak arch_split_mtd_part(struct mtd_info *master, const char *name,
+ int offset, int size)
+{
+}
+
+static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part)
+{
+ static int rootfs_found = 0;
+
+ if (rootfs_found)
+ return;
+
+ if (!strcmp(part->mtd.name, "rootfs")) {
+ rootfs_found = 1;
+
+ if (config_enabled(CONFIG_MTD_ROOTFS_SPLIT))
+ split_rootfs_data(master, part);
+ }
+
+ if (!strcmp(part->mtd.name, SPLIT_FIRMWARE_NAME) &&
+ config_enabled(CONFIG_MTD_SPLIT_FIRMWARE))
+ split_firmware(master, part);
+
+ arch_split_mtd_part(master, part->mtd.name, part->offset,
+ part->mtd.size);
+}
/*
* This function, given a master MTD object and a partition table, creates
* and registers slave MTD objects which are bound to the master according to
@@ -643,6 +794,7 @@ int add_mtd_partitions(struct mtd_info *
mutex_unlock(&mtd_partitions_mutex);
add_mtd_device(&slave->mtd);
+ mtd_partition_split(master, slave);
cur_offset = slave->offset + slave->mtd.size;
}
--- a/include/linux/mtd/partitions.h
+++ b/include/linux/mtd/partitions.h
@@ -84,5 +84,7 @@ int mtd_add_partition(struct mtd_info *m
long long offset, long long length);
int mtd_del_partition(struct mtd_info *master, int partno);
uint64_t mtd_get_device_size(const struct mtd_info *mtd);
+extern void __weak arch_split_mtd_part(struct mtd_info *master,
+ const char *name, int offset, int size);
#endif