Merge branch 'for-next/blspec'

14 files changed, 166 insertions, 1 deletions

diff --git a/Documentation/filesystems/nfs.rst b/Documentation/filesystems/nfs.rst
index f4eda5d13c..4469ac1dff 100644
--- a/Documentation/filesystems/nfs.rst
+++ b/Documentation/filesystems/nfs.rst
@@ -10,3 +10,16 @@ barebox has readonly support for NFSv3 in UDP mode.
 Example::
 
    mount -t nfs 192.168.23.4:/home/user/nfsroot /mnt/nfs
+
+The barebox NFS driver adds a ``linux.bootargs`` device parameter to the NFS device.
+This parameter holds a Linux kernel commandline snippet containing a suitable root=
+option for booting from exactly that NFS share.
+
+Example::
+
+  devinfo nfs0
+  ...
+  linux.bootargs: root=/dev/nfs nfsroot=192.168.23.4:/home/sha/nfsroot/generic-v7,v3,tcp
+
+The options default to ``v3,tcp`` but can be adjusted before mounting the NFS share with
+the ``global.linux.rootnfsopts`` variable
diff --git a/Documentation/user/booting-linux.rst b/Documentation/user/booting-linux.rst
index 6e7d1550bf..39084e5afe 100644
--- a/Documentation/user/booting-linux.rst
+++ b/Documentation/user/booting-linux.rst
@@ -205,6 +205,13 @@ compatible NFS URI string must be passed to the boot command:
 
   boot nfs://nfshost//path/
 
+Additionally to the options defined in the original spec barebox understands the
+``linux-appendroot`` option. This is a boolean value and if set to ``true`` barebox
+will automatically append a ``root=`` string to the Linux commandline based on the
+device where the entry is found on. This makes it possible to use the same rootfs
+image on different devices without having to specify a different root= option each
+time.
+
 Network boot
 ------------
 
diff --git a/common/blspec.c b/common/blspec.c
index 7e84ff3cec..ab18602715 100644
--- a/common/blspec.c
+++ b/common/blspec.c
@@ -634,6 +634,29 @@ int blspec_scan_devicename(struct blspec *blspec, const char *devname)
 	return blspec_scan_device(blspec, dev);
 }
 
+static int blspec_append_root(struct blspec_entry *entry)
+{
+	const char *appendroot;
+	char *rootarg;
+
+	appendroot = blspec_entry_var_get(entry, "linux-appendroot");
+	if (!appendroot || strcmp(appendroot, "true"))
+		return 0;
+
+	rootarg = path_get_linux_rootarg(entry->rootpath);
+	if (IS_ERR(rootarg)) {
+		pr_err("Getting root argument for %s failed with: %s\n",
+				entry->rootpath, strerror(-PTR_ERR(rootarg)));
+		return PTR_ERR(rootarg);
+	}
+
+	globalvar_add_simple("linux.bootargs.dyn.blspec.appendroot", rootarg);
+
+	free(rootarg);
+
+	return 0;
+}
+
 /*
  * blspec_boot - boot an entry
  *
@@ -683,6 +706,10 @@ int blspec_boot(struct blspec_entry *entry, int verbose, int dryrun)
 
 	globalvar_add_simple("linux.bootargs.dyn.blspec", options);
 
+	ret = blspec_append_root(entry);
+	if (ret)
+		goto err_out;
+
 	pr_info("booting %s from %s\n", blspec_entry_var_get(entry, "title"),
 			entry->cdev ? dev_name(entry->cdev->dev) : "none");
 
@@ -701,7 +728,7 @@ int blspec_boot(struct blspec_entry *entry, int verbose, int dryrun)
 	ret = bootm_boot(&data);
 	if (ret)
 		pr_err("Booting failed\n");
-
+err_out:
 	free((char *)data.oftree_file);
 	free((char *)data.initrd_file);
 	free((char *)data.os_file);
diff --git a/common/partitions.c b/common/partitions.c
index 37d9cb7edc..4f50bfeff1 100644
--- a/common/partitions.c
+++ b/common/partitions.c
@@ -64,6 +64,7 @@ static int register_one_partition(struct block_device *blk,
 	}
 
 	cdev->dos_partition_type = part->dos_partition_type;
+	strcpy(cdev->partuuid, part->partuuid);
 
 	free(partition_name);
 
diff --git a/common/partitions/dos.c b/common/partitions/dos.c
index 37addfd2ef..e0cb35627d 100644
--- a/common/partitions/dos.c
+++ b/common/partitions/dos.c
@@ -185,6 +185,7 @@ static void dos_partition(void *buf, struct block_device *blk,
 	uint8_t *buffer = buf;
 	int i;
 	struct disk_signature_priv *dsp;
+	uint32_t signature = get_unaligned_le32(buf + 0x1b8);
 
 	table = (struct partition_entry *)&buffer[446];
 
@@ -202,6 +203,9 @@ static void dos_partition(void *buf, struct block_device *blk,
 			pd->parts[n].first_sec = pentry.first_sec;
 			pd->parts[n].size = pentry.size;
 			pd->parts[n].dos_partition_type = pentry.dos_partition_type;
+			if (signature)
+				sprintf(pd->parts[n].partuuid, "%08x-%02d",
+						signature, i + 1);
 			pd->used_entries++;
 			/*
 			 * Partitions of type 0x05 and 0x0f (and some more)
diff --git a/common/partitions/parser.h b/common/partitions/parser.h
index 8d39452378..8ad134a9aa 100644
--- a/common/partitions/parser.h
+++ b/common/partitions/parser.h
@@ -17,6 +17,7 @@
 struct partition {
 	char name[MAX_PARTITION_NAME];
 	u8 dos_partition_type;
+	char partuuid[MAX_PARTUUID_STR];
 	uint64_t first_sec;
 	uint64_t size;
 };
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 08cb8dd7e0..7fc1aa8d70 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -36,6 +36,7 @@ void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di)
 	di->min_io_size = ubi->min_io_size;
 	di->max_write_size = ubi->max_write_size;
 	di->ro_mode = ubi->ro_mode;
+	di->mtd = ubi->mtd;
 }
 EXPORT_SYMBOL_GPL(ubi_do_get_device_info);
 
diff --git a/fs/fs.c b/fs/fs.c
index c249f843bf..67c78cd111 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -1298,6 +1298,12 @@ int mount(const char *device, const char *fsname, const char *_path,
 		goto err_no_driver;
 	}
 
+	if (!fsdev->linux_rootarg && fsdev->cdev && fsdev->cdev->partuuid[0] != 0) {
+		char *str = asprintf("root=PARTUUID=%s", fsdev->cdev->partuuid);
+
+		fsdev_set_linux_rootarg(fsdev, str);
+	}
+
 	return 0;
 
 err_no_driver:
@@ -1708,3 +1714,34 @@ void mount_all(void)
 			cdev_mount_default(cdev, NULL);
 	}
 }
+
+void fsdev_set_linux_rootarg(struct fs_device_d *fsdev, const char *str)
+{
+	fsdev->linux_rootarg = xstrdup(str);
+
+	dev_add_param_fixed(&fsdev->dev, "linux.bootargs", fsdev->linux_rootarg);
+}
+
+/**
+ * path_get_linux_rootarg() - Given a path return a suitable root= option for
+ *                            Linux
+ * @path: The path
+ *
+ * Return: A string containing the root= option or an ERR_PTR. the returned
+ *         string must be freed by the caller.
+ */
+char *path_get_linux_rootarg(const char *path)
+{
+	struct fs_device_d *fsdev;
+	const char *str;
+
+	fsdev = get_fsdevice_by_path(path);
+	if (!fsdev)
+		return ERR_PTR(-EINVAL);
+
+	str = dev_get_param(&fsdev->dev, "linux.bootargs");
+	if (!str)
+		return ERR_PTR(-ENOSYS);
+
+	return xstrdup(str);
+}
diff --git a/fs/nfs.c b/fs/nfs.c
index 2738c781d7..5bff54a4dd 100644
--- a/fs/nfs.c
+++ b/fs/nfs.c
@@ -35,6 +35,7 @@
 #include <kfifo.h>
 #include <linux/sizes.h>
 #include <byteorder.h>
+#include <globalvar.h>
 
 #include "parseopt.h"
 
@@ -1306,6 +1307,23 @@ static int nfs_stat(struct device_d *dev, const char *filename, struct stat *s)
 	}
 }
 
+static char *rootnfsopts;
+
+static void nfs_set_rootarg(struct nfs_priv *npriv, struct fs_device_d *fsdev)
+{
+	char *str;
+	const char *ip;
+
+	ip = ip_to_string(npriv->server);
+	str = asprintf("root=/dev/nfs nfsroot=%s:%s%s%s",
+			ip, npriv->path, rootnfsopts[0] ? "," : "",
+			rootnfsopts);
+
+	fsdev_set_linux_rootarg(fsdev, str);
+
+	free(str);
+}
+
 static int nfs_probe(struct device_d *dev)
 {
 	struct fs_device_d *fsdev = dev_to_fs_device(dev);
@@ -1369,6 +1387,8 @@ static int nfs_probe(struct device_d *dev)
 		goto err2;
 	}
 
+	nfs_set_rootarg(npriv, fsdev);
+
 	free(tmp);
 
 	return 0;
@@ -1421,6 +1441,10 @@ static struct fs_driver_d nfs_driver = {
 
 static int nfs_init(void)
 {
+	rootnfsopts = xstrdup("v3,tcp");
+
+	globalvar_add_simple_string("linux.rootnfsopts", &rootnfsopts);
+
 	return register_fs_driver(&nfs_driver);
 }
 coredevice_initcall(nfs_init);
diff --git a/fs/ubifs/ubifs.c b/fs/ubifs/ubifs.c
index 68d90b36e7..a9189f76b5 100644
--- a/fs/ubifs/ubifs.c
+++ b/fs/ubifs/ubifs.c
@@ -36,6 +36,7 @@
 #include <linux/zlib.h>
 #include <xfuncs.h>
 #include <fcntl.h>
+#include <linux/mtd/mtd.h>
 
 #include "ubifs.h"
 
@@ -584,6 +585,26 @@ static int ubifs_readlink(struct device_d *dev, const char *pathname, char *buf,
 	return 0;
 }
 
+static void ubifs_set_rootarg(struct ubifs_priv *priv, struct fs_device_d *fsdev)
+{
+	struct ubi_volume_info vi = {};
+	struct ubi_device_info di = {};
+	struct mtd_info *mtd;
+	char *str;
+
+	ubi_get_volume_info(priv->ubi, &vi);
+	ubi_get_device_info(vi.ubi_num, &di);
+
+	mtd = di.mtd;
+
+	str = asprintf("root=ubi0:%s ubi.mtd=%s rootfstype=ubifs",
+			vi.name, mtd->cdev.partname);
+
+	fsdev_set_linux_rootarg(fsdev, str);
+
+	free(str);
+}
+
 static int ubifs_probe(struct device_d *dev)
 {
 	struct fs_device_d *fsdev = dev_to_fs_device(dev);
@@ -612,6 +633,8 @@ static int ubifs_probe(struct device_d *dev)
 		goto err;
 	}
 
+	ubifs_set_rootarg(priv, fsdev);
+
 	return 0;
 err:
 	ubi_close_volume(priv->ubi);
diff --git a/include/driver.h b/include/driver.h
index d0cdcc9715..9c6005454c 100644
--- a/include/driver.h
+++ b/include/driver.h
@@ -435,6 +435,8 @@ struct file_operations {
 	int (*memmap)(struct cdev*, void **map, int flags);
 };
 
+#define MAX_PARTUUID_STR	sizeof("00112233-4455-6677-8899-AABBCCDDEEFF")
+
 struct cdev {
 	struct file_operations *ops;
 	void *priv;
@@ -445,6 +447,7 @@ struct cdev {
 	char *partname; /* the partition name, usually the above without the
 			 * device part, i.e. name = "nand0.barebox" -> partname = "barebox"
 			 */
+	char partuuid[MAX_PARTUUID_STR];
 	loff_t offset;
 	loff_t size;
 	unsigned int flags;
diff --git a/include/fs.h b/include/fs.h
index f95464de6a..ee7e48b0f9 100644
--- a/include/fs.h
+++ b/include/fs.h
@@ -100,6 +100,7 @@ struct fs_device_d {
 	struct device_d *parent_device;
 	struct list_head list;
 	char *options;
+	char *linux_rootarg;
 };
 
 #define drv_to_fs_driver(d) container_of(d, struct fs_driver_d, drv)
@@ -189,4 +190,7 @@ const char *cdev_get_mount_path(struct cdev *cdev);
 const char *cdev_mount_default(struct cdev *cdev, const char *fsoptions);
 void mount_all(void);
 
+void fsdev_set_linux_rootarg(struct fs_device_d *fsdev, const char *str);
+char *path_get_linux_rootarg(const char *path);
+
 #endif /* __FS_H */
diff --git a/include/globalvar.h b/include/globalvar.h
index 8b2caf1f8b..6e10956b89 100644
--- a/include/globalvar.h
+++ b/include/globalvar.h
@@ -17,6 +17,20 @@ int globalvar_add(const char *name,
 char *globalvar_get_match(const char *match, const char *separator);
 void globalvar_set_match(const char *match, const char *val);
 
+static inline int globalvar_add_simple_string(const char *name,
+		char **value)
+{
+	struct param_d *p;
+
+	p = dev_add_param_string(&global_device, name, NULL, NULL,
+		value, NULL);
+
+	if (IS_ERR(p))
+		return PTR_ERR(p);
+
+	return 0;
+}
+
 static inline int globalvar_add_simple_int(const char *name,
 		int *value, const char *format)
 {
@@ -85,6 +99,11 @@ static inline int globalvar_add_simple(const char *name, const char *value)
 	return 0;
 }
 
+static inline int globalvar_add_simple_string(const char *name, char **value)
+{
+	return 0;
+}
+
 static inline int globalvar_add_simple_int(const char *name,
 		int *value, const char *format)
 {
diff --git a/include/linux/mtd/ubi.h b/include/linux/mtd/ubi.h
index 274ec4ee41..0614681d73 100644
--- a/include/linux/mtd/ubi.h
+++ b/include/linux/mtd/ubi.h
@@ -154,6 +154,7 @@ struct ubi_device_info {
 	int max_write_size;
 	int ro_mode;
 	dev_t cdev;
+	struct mtd_info *mtd;
 };
 
 /*