Improve swupdate completion documentation

Outcome of the discussion in #517.

Signed-off-by: Jan Kiszka <[email protected]>

README.md

@@ -208,7 +208,12 @@ $ complete_update.sh
 ```
 
 The script sets the update state in the EFI Boot Guard configuration to the
-initial state.
+"success" state. It shall be considered as a placeholder for a more precise
+logic which first needs to validate if the new image version is sufficiently
+functional to accept the next update. The exact condition for this depends on
+the concrete integration and the way how updates are deployed to the device.
+If the update happens over network, checking the connection to the update
+server first before confirming the update is strongly recommended.
 
 If the update is deemed failed, resetting the device will select the previous
 root file system.

recipes-core/swupdate-complete-update-helper/swupdate-complete-update-helper_0.1.bb

@@ -14,7 +14,6 @@ SRC_URI = "file://complete_update.sh"
 DEBIAN_DEPENDS = "efibootguard"
 
 do_install() {
-    # add board status led service
     install -v -d ${D}/usr/bin
     install -v -m 644 ${WORKDIR}/complete_update.sh ${D}/usr/bin/complete_update.sh
 }