swupdate: do not run swupdate daemon on non-dualboot devices

On recovery based devices, the swupdate process is executed in the
recovery, so there is no need to have the swupdate daemon running on the
rootfs.

Add a on-target post installation script to disable the swupdate
bootscript on the normal rootfs. This has the side effect of failing in
the recovery initramfs because the initramfs does not have a complete
SysV init system. For that case add a rootfs postprocess function to
delete the postinst script.

Signed-off-by: Javier Viguera <javier.viguera@digi.com>

meta-digi-dey/recipes-core/images/dey-image-recovery-initramfs.bb

@@ -34,3 +34,9 @@ BAD_RECOMMENDATIONS += " \
 "
 
 export IMAGE_BASENAME = "dey-image-recovery-initramfs"
+
+initramfs_cleanup() {
+	# Delete SWUPDATE postinst script
+	rm -f ${IMAGE_ROOTFS}${sysconfdir}/rpm-postinsts/*swupdate*
+}
+ROOTFS_POSTPROCESS_COMMAND += "initramfs_cleanup; "

meta-digi-dey/recipes-support/swupdate/swupdate_2022.05.bbappend

@@ -28,3 +28,9 @@ do_install:append() {
 	install -d ${D}${bindir}/
 	install -m 0755 tools/swupdate-progress ${D}${bindir}/progress
 }
+
+pkg_postinst_ontarget:${PN}() {
+	if ${@bb.utils.contains('DISTRO_FEATURES','systemd','false','true',d)}; then
+		[ "$(fw_printenv -n dualboot 2>/dev/null)" = "no" ] && update-rc.d -f swupdate remove
+	fi
+}