initscripts/sysfs.sh: Mount devtmpfs on /dev/ if needed

When booting from an initrd disk, or when the kernel config option
DEVTMPFS_MOUNT isn't provided, /dev/ will not be mounted at boot.

This small addition will check if /dev/ is "useful", and if not, will
mount devtmpfs if the kernel provides it.

With this change, it is possible to set an initscripts style image type
to "cpio.gz" and boot it as initrd. Without this change, the image won't
work properly because of the missing devices.

(From OE-Core rev: a1cfb8a2691ed36700c96cbc1a0e744494294d2b)

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/meta/recipes-core/initscripts/initscripts-1.0/sysfs.sh b/meta/recipes-core/initscripts/initscripts-1.0/sysfs.sh
index 0cfe76e230..0a52c90dac 100644
--- a/meta/recipes-core/initscripts/initscripts-1.0/sysfs.sh
+++ b/meta/recipes-core/initscripts/initscripts-1.0/sysfs.sh
@@ -21,3 +21,7 @@ fi
 if [ -e /sys/kernel/debug ] && grep -q debugfs /proc/filesystems; then
   mount -t debugfs debugfs /sys/kernel/debug
 fi
+
+if ! [ -e /dev/zero ] && [ -e /dev ] && grep -q devtmpfs /proc/filesystems; then
+  mount -n -t devtmpfs devtmpfs /dev
+fi