wic/help.py: document requirements for valid fstab generation

Without one of the --ondrive, --ondisk or --use-uuid options for a
partition with a mountpoint specified the automatically generated
fstab entry will be invalid.

[YOCTO #8844]

(From OE-Core rev: a524ced19db05e776834cd1f1db03c68a05f9c0b)

Signed-off-by: Joshua Lock <joshua.g.lock@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/scripts/lib/wic/help.py b/scripts/lib/wic/help.py
index be334e7814..f5587bbba7 100644
--- a/scripts/lib/wic/help.py
+++ b/scripts/lib/wic/help.py
@@ -629,6 +629,13 @@ DESCRIPTION
        If a <mountpoint> is not specified the partition will be created
        but will not be mounted.
 
+       Partitions with a <mountpoint> specified will be automatically mounted.
+       This is achieved by wic adding entries to the fstab during image
+       generation. In order for a valid fstab to be generated one of the
+       --ondrive, --ondisk or --use-uuid partition options must be used for
+       each partition that specifies a mountpoint.
+
+
        The following are supported 'part' options:
 
          --size: The minimum partition size. Specify an integer value