ref-manual: Added and updated variables to support calling functions

Fixed [YOCTO #7632]

Looked for, updated, and added (if necessary) the following
variables:

 * ROOTFS_PREPROCESS_COMMAND
 * ROOTFS_POSTPROCESS_COMMAND
 * SDK_POSTPROCESS_COMMAND
 * POPULATE_SDK_POST_TARGET_COMMAND
 * POPULATE_SDK_POST_HOST_COMMAND,
 * IMAGE_POSTPROCESS_COMMAND
 * IMAGE_PREPROCESS_COMMAND
 * ROOTFS_POSTUNINSTALL_COMMAND
 * ROOTFS_POSTINSTALL_COMMAND

Each of these variables no longer accepts arbitrary shell commands but
rather functions.  The wordings now support that behavior.

Also, updated the migration section for going to 1.6 release to note
this change.

(From yocto-docs rev: e1ab48f7def9d1eb080e007b88f75172470b8007)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/documentation/ref-manual/migration.xml b/documentation/ref-manual/migration.xml
index 7c78c9dd50..984485ede2 100644
--- a/documentation/ref-manual/migration.xml
+++ b/documentation/ref-manual/migration.xml
@@ -1413,6 +1413,35 @@
                 it encounters the variable.
             </para>
         </section>
+
+        <section id='migration-1.6-variable-changes-variable-entry-behavior'>
+            <title>Preprocess and Post Process Command Variable Behavior</title>
+
+            <para>
+                The following variables now expect a semicolon separated
+                list of functions to call and not arbitrary shell commands:
+                <literallayout class='monospaced'>
+     <link linkend='var-ROOTFS_PREPROCESS_COMMAND'>ROOTFS_PREPROCESS_COMMAND</link>
+     <link linkend='var-ROOTFS_POSTPROCESS_COMMAND'>ROOTFS_POSTPROCESS_COMMAND</link>
+     <link linkend='var-SDK_POSTPROCESS_COMMAND'>SDK_POSTPROCESS_COMMAND</link>
+     <link linkend='var-POPULATE_SDK_POST_TARGET_COMMAND'>POPULATE_SDK_POST_TARGET_COMMAND</link>
+     <link linkend='var-POPULATE_SDK_POST_HOST_COMMAND'>POPULATE_SDK_POST_HOST_COMMAND</link>
+     <link linkend='var-IMAGE_POSTPROCESS_COMMAND'>IMAGE_POSTPROCESS_COMMAND</link>
+     <link linkend='var-IMAGE_PREPROCESS_COMMAND'>IMAGE_PREPROCESS_COMMAND</link>
+     <link linkend='var-ROOTFS_POSTUNINSTALL_COMMAND'>ROOTFS_POSTUNINSTALL_COMMAND</link>
+     <link linkend='var-ROOTFS_POSTINSTALL_COMMAND'>ROOTFS_POSTINSTALL_COMMAND</link>
+                </literallayout>
+                For migration purposes, you can simply wrap shell commands in
+                a shell function and then call the function.
+                Here is an example:
+                <literallayout class='monospaced'>
+     my_postprocess_function() {
+        echo "hello" > ${IMAGE_ROOTFS}/hello.txt
+     }
+     ROOTFS_POSTPROCESS_COMMAND += "my_postprocess_function; "
+                </literallayout>
+            </para>
+        </section>
     </section>
 
     <section id='migration-1.6-directory-layout-changes'>