1 files changed, 24 insertions, 17 deletions
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index ee377270beb9..8021e19fa1ea 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -9,29 +9,36 @@ config UEVENT_HELPER_PATH
          every uevent.
 config DEVTMPFS
-        bool "Create a kernel maintained /dev tmpfs (EXPERIMENTAL)"
+        bool "Maintain a devtmpfs filesystem to mount at /dev"
        depends on HOTPLUG && SHMEM && TMPFS
        help
-          This creates a tmpfs filesystem, and mounts it at bootup
+          This creates a tmpfs filesystem instance early at bootup.
-          and mounts it at /dev. The kernel driver core creates device
+          In this filesystem, the kernel driver core maintains device
-          nodes for all registered devices in that filesystem. All device
+          nodes with their default names and permissions for all
-          nodes are owned by root and have the default mode of 0600.
+          registered devices with an assigned major/minor number.
-          Userspace can add and delete the nodes as needed. This is
+          Userspace can modify the filesystem content as needed, add
-          intended to simplify bootup, and make it possible to delay
+          symlinks, and apply needed permissions.
-          the initial coldplug at bootup done by udev in userspace.
+          It provides a fully functional /dev directory, where usually
-          It should also provide a simpler way for rescue systems
+          udev runs on top, managing permissions and adding meaningful
-          to bring up a kernel with dynamic major/minor numbers.
+          symlinks.
-          Meaningful symlinks, permissions and device ownership must
+          In very limited environments, it may provide a sufficient
-          still be handled by userspace.
+          functional /dev without any further help. It also allows simple
-          If unsure, say N here.
+          rescue systems, and reliably handles dynamic major/minor numbers.
 config DEVTMPFS_MOUNT
-        bool "Automount devtmpfs at /dev"
+        bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs"
        depends on DEVTMPFS
        help
-          This will mount devtmpfs at /dev if the kernel mounts the root
+          This will instruct the kernel to automatically mount the
-          filesystem. It will not affect initramfs based mounting.
+          devtmpfs filesystem at /dev, directly after the kernel has
-          If unsure, say N here.
+          mounted the root filesystem. The behavior can be overridden
+          with the commandline parameter: devtmpfs.mount=0|1.
+          This option does not affect initramfs based booting, here
+          the devtmpfs filesystem always needs to be mounted manually
+          after the roots is mounted.
+          With this option enabled, it allows to bring up a system in
+          rescue mode with init=/bin/sh, even when the /dev directory
+          on the rootfs is completely empty.
 config STANDALONE
        bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL

diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index ee377270beb9..8021e19fa1ea 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig
@@ -9,29 +9,36 @@ config UEVENT_HELPER_PATH
9	every uevent.	9	every uevent.
10		10
11	config DEVTMPFS	11	config DEVTMPFS
12	bool "Create a kernel maintained /dev tmpfs (EXPERIMENTAL)"	12	bool "Maintain a devtmpfs filesystem to mount at /dev"
13	depends on HOTPLUG && SHMEM && TMPFS	13	depends on HOTPLUG && SHMEM && TMPFS
14	help	14	help
15	This creates a tmpfs filesystem, and mounts it at bootup	15	This creates a tmpfs filesystem instance early at bootup.
16	and mounts it at /dev. The kernel driver core creates device	16	In this filesystem, the kernel driver core maintains device
17	nodes for all registered devices in that filesystem. All device	17	nodes with their default names and permissions for all
18	nodes are owned by root and have the default mode of 0600.	18	registered devices with an assigned major/minor number.
19	Userspace can add and delete the nodes as needed. This is	19	Userspace can modify the filesystem content as needed, add
20	intended to simplify bootup, and make it possible to delay	20	symlinks, and apply needed permissions.
21	the initial coldplug at bootup done by udev in userspace.	21	It provides a fully functional /dev directory, where usually
22	It should also provide a simpler way for rescue systems	22	udev runs on top, managing permissions and adding meaningful
23	to bring up a kernel with dynamic major/minor numbers.	23	symlinks.
24	Meaningful symlinks, permissions and device ownership must	24	In very limited environments, it may provide a sufficient
25	still be handled by userspace.	25	functional /dev without any further help. It also allows simple
26	If unsure, say N here.	26	rescue systems, and reliably handles dynamic major/minor numbers.
27		27
28	config DEVTMPFS_MOUNT	28	config DEVTMPFS_MOUNT
29	bool "Automount devtmpfs at /dev"	29	bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs"
30	depends on DEVTMPFS	30	depends on DEVTMPFS
31	help	31	help
32	This will mount devtmpfs at /dev if the kernel mounts the root	32	This will instruct the kernel to automatically mount the
33	filesystem. It will not affect initramfs based mounting.	33	devtmpfs filesystem at /dev, directly after the kernel has
34	If unsure, say N here.	34	mounted the root filesystem. The behavior can be overridden
		35	with the commandline parameter: devtmpfs.mount=0\|1.
		36	This option does not affect initramfs based booting, here
		37	the devtmpfs filesystem always needs to be mounted manually
		38	after the roots is mounted.
		39	With this option enabled, it allows to bring up a system in
		40	rescue mode with init=/bin/sh, even when the /dev directory
		41	on the rootfs is completely empty.
35		42
36	config STANDALONE	43	config STANDALONE
37	bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL	44	bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL