convert to UUID; make panic-reboot-time a flag; prevent automatic fsck

note: uuid.patch currently still panics ☹

Signed-off-by: Thorsten Glaser <tg@mirbsd.org>

1 files changed, 174 insertions, 0 deletions

diff --git a/target/linux/patches/2.6.36/uuid.patch b/target/linux/patches/2.6.36/uuid.patch
new file mode 100644
index 000000000..2e6c61df9
--- /dev/null
+++ b/target/linux/patches/2.6.36/uuid.patch
@@ -0,0 +1,174 @@
+# DP: Add support for specifying the root device using UUIDs on the
+# DP: kernel command line like this without the need for an initrd:
+# DP: linux ... root=UUID=ce40d6b2-18eb-4a75-aefe-7ddb0995ce63
+# DP:
+# DP: Written © 2010 by Thorsten Glaser <tg@debian.org>
+# DP: Idea from 1999 by David Balazic <david.balazic@uni-mb.si>
+
+--- linux-2.6.36/block/genhd.c~	Wed Oct 20 22:30:22 2010
++++ linux-2.6.36/block/genhd.c	Sat Nov 20 23:14:03 2010
+@@ -35,7 +35,7 @@ struct kobject *block_depr;
+ static DEFINE_MUTEX(ext_devt_mutex);
+ static DEFINE_IDR(ext_devt_idr);
+ 
+-static struct device_type disk_type;
++struct device_type disk_type;
+ 
+ /**
+  * disk_get_part - get partition
+@@ -1019,7 +1019,7 @@ static char *block_devnode(struct device *dev, mode_t 
+ 	return NULL;
+ }
+ 
+-static struct device_type disk_type = {
++struct device_type disk_type = {
+ 	.name		= "disk",
+ 	.groups		= disk_attr_groups,
+ 	.release	= disk_release,
+--- linux-2.6.36/init/do_mounts.c~	Wed Oct 20 22:30:22 2010
++++ linux-2.6.36/init/do_mounts.c	Sat Nov 20 23:16:07 2010
+@@ -32,6 +32,84 @@ static int __initdata root_wait;
+ 
+ dev_t ROOT_DEV;
+ 
++#ifdef CONFIG_EXT2_FS
++/* support for root=UUID=ce40d6b2-18eb-4a75-aefe-7ddb0995ce63 bootargs */
++
++#include <linux/buffer_head.h>
++#include <linux/ext2_fs.h>
++
++__u8 root_dev_label[16];
++int root_dev_type;	/* 0 = normal (/dev/hda1, 0301); 1 = UUID; 3 = bad */
++
++/* imported from block/genhd.c after removing its static qualifier */
++extern struct device_type disk_type;
++
++static __u8 __init fromhex(char c)
++{
++	if (c >= '0' && c <= '9')
++		return (c - '0');
++	c &= ~32;
++	if (c >= 'A' && c <= 'F')
++		return (c - 'A' + 10);
++	return (0xFF);
++}
++
++static void __init parse_uuid(const char *s)
++{
++	int i;
++	__u8 j, k;
++
++	if (strlen(s) != 36 || s[8] != '-' || s[13] != '-' ||
++	    s[18] != '-' || s[23] != '-')
++		goto bad_uuid;
++	for (i = 0; i < 16; i++) {
++		if (*s == '-')
++			++s;
++		j = fromhex(*s++);
++		k = fromhex(*s++);
++		if (j == 0xFF || k == 0xFF)
++			goto bad_uuid;
++		root_dev_label[i] = (j << 4) | k;
++	}
++	return;
++ bad_uuid:
++	/* we cannot panic here, defer */
++	root_dev_type = 3;
++}
++
++static int __init check_dev(dev_t devt, int blocksize)
++{
++	/* most of this taken from fs/ext2/super.c */
++
++	struct buffer_head * bh;
++	struct ext2_super_block * es;
++	struct block_device *bdev;
++	unsigned long sb_block = 1;
++	unsigned long logic_sb_block;
++	unsigned long offset = 0;
++	int rv = 0;
++
++	bdev = bdget(devt);
++
++	if (blocksize != BLOCK_SIZE) {
++		logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
++		offset = (sb_block*BLOCK_SIZE) % blocksize;
++	} else {
++		logic_sb_block = sb_block;
++	}
++
++	if (!(bh = __bread(bdev, logic_sb_block, blocksize)))
++		return (0);
++	es = (struct ext2_super_block *)(((char *)bh->b_data) + offset);
++	if (le16_to_cpu(es->s_magic) == EXT2_SUPER_MAGIC) {
++		if (!memcmp(es->s_uuid, root_dev_label, 16))
++			rv = 1;
++	}
++	brelse(bh);
++	return (rv);
++}
++#endif /* CONFIG_EXT2_FS for UUID support */
++
+ static int __init load_ramdisk(char *str)
+ {
+ 	rd_doload = simple_strtol(str,NULL,0) & 3;
+@@ -148,6 +226,13 @@ done:
+ static int __init root_dev_setup(char *line)
+ {
+ 	strlcpy(saved_root_name, line, sizeof(saved_root_name));
++#ifdef CONFIG_EXT2_FS
++	root_dev_type = 0;
++	if (!strncmp(line, "UUID=", 5)) {
++		root_dev_type = 1;
++		parse_uuid(line + 5);
++	}
++#endif /* CONFIG_EXT2_FS for UUID support */
+ 	return 1;
+ }
+ 
+@@ -333,6 +418,45 @@ void __init change_floppy(char *fmt, ...)
+ 
+ void __init mount_root(void)
+ {
++#ifdef CONFIG_EXT2_FS
++	/* UUID support */
++	if (root_dev_type == 1) {
++		int blocksize;
++
++		/* from block/genhd.c printk_all_partitions */
++		struct class_dev_iter iter;
++		struct device *dev;
++
++		class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
++		while (root_dev_type && (dev = class_dev_iter_next(&iter))) {
++			struct gendisk *disk = dev_to_disk(dev);
++			struct disk_part_iter piter;
++			struct hd_struct *part;
++			if (get_capacity(disk) == 0 ||
++			    (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
++				continue;
++			blocksize = queue_logical_block_size(disk->queue);
++
++			disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
++			while (root_dev_type && (part = disk_part_iter_next(&piter))) {
++				/* avoid empty or too small partitions */
++				if (part->nr_sects < 8)
++					continue;
++				if (check_dev(part_devt(part), blocksize)) {
++					ROOT_DEV = part_devt(part);
++					root_dev_type = 0;
++				}
++			}
++			disk_part_iter_exit(&piter);
++		}
++		class_dev_iter_exit(&iter);
++	}
++	if (root_dev_type == 1)
++		printk(KERN_ERR "VFS: Unable to find root by UUID %s.\n", saved_root_name + 5);
++	else if (root_dev_type == 3)
++		panic("Badly formatted UUID %s was supplied as kernel parameter root", saved_root_name + 5);
++#endif /* CONFIG_EXT2_FS for UUID support */
++
+ #ifdef CONFIG_ROOT_NFS
+ 	if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
+ 		if (mount_nfs_root())