[Buildroot] [PATCH 2/2] skeleton: fix absence of /dev/shm on static, read-only systems

[Luca Ceresoli]

/dev/shm is needed for systems using shared memory. On init-based systems
this directory is usually created in the inittab along with /dev/pts, by
the lines:

package/busybox/inittab:
  ::sysinit:/bin/mkdir -p /dev/pts
  ::sysinit:/bin/mkdir -p /dev/shm

package/sysvinit/inittab:
  si2::sysinit:/bin/mkdir -p /dev/pts
  si3::sysinit:/bin/mkdir -p /dev/shm

However this is broken when static /dev management is selected and the root
filesystem is read-only, showing during boot the error:

  mkdir: can't create directory '/dev/shm': Read-only file system

Fix by creating the empth /dev/shm directory, just like /dev/pts.

Signed-off-by: Luca Ceresoli <luca at lucaceresoli.net>
---
 system/skeleton/dev/shm/.empty | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 system/skeleton/dev/shm/.empty

diff --git a/system/skeleton/dev/shm/.empty b/system/skeleton/dev/shm/.empty
new file mode 100644
index 0000000..e69de29
-- 
1.9.1