1 files changed, 55 insertions, 0 deletions
diff --git a/conf/swupd/swupd-config.inc b/conf/swupd/swupd-config.inc
new file mode 100644
index 0000000..bb9eaa5
--- /dev/null
+++ b/conf/swupd/swupd-config.inc
@@ -0,0 +1,55 @@
+# The "format" needs to be bumped for different reasons:
+# - the output of the swupd-server changes in a way that
+#   a swupd-client currently installed on devices  will not
+#   understand it (example: changing file names or using
+#   a new compression method for archives)
+# - the content of the distro changes such that a device
+#   cannot update directly to the latest build (example:
+#   the distro changes the boot loader and some swupd postinst
+#   helper which knows about that change must be installed on
+#   the device first before actually switching)
+#
+# meta-swupd handles the first case with SWUPD_TOOLS_FORMAT.
+# The default value matches the default versions of the swupd-server
+# and swupd-client. Distros can override this if they need to pick
+# non-default versions of the tools, but that is not tested.
+#
+# Distros need to handle the second case by preparing and releasing
+# a build that devices can update to (i.e. the version URL the devices
+# check must have that update), then make the incompatible change and
+# in the next build bump the SWUPD_DISTRO_FORMAT.
+#
+# In both cases, SWUPD_FORMAT gets bumped. meta-swupd notices that
+# and then prepares a special transitional update:
+# - the rootfs is configured to use the new SWUUPD_FORMAT and
+#   OS_VERSION
+# - a fake OS_VERSION-1 release is built using a swupd-server that is
+#   compatible with the swupd-client before the bump
+# - the OS_VERSION release then is the first one using the new format
+#
+# This way, devices are forced to update to OS_VERSION-1 because that
+# will forever be the "latest" version for their current format.
+# Once they have updated, the device really is on OS_VERSION, configured
+# to use the new format, and the next update check will see future
+# releases again.
+#
+# For this to work, "swupd-client" should always be invoked without
+# explicit format parameter.
+SWUPD_TOOLS_FORMAT ?= "4"
+SWUPD_DISTRO_FORMAT ?= "0"
+SWUPD_FORMAT = "${@ str(int('${SWUPD_TOOLS_FORMAT}') + int('${SWUPD_DISTRO_FORMAT}')) }"
+
+
+# This version number *must* map to VERSION_ID in /etc/os-release and *must* be
+# a non-negative integer that fits in an int.
+OS_VERSION ??= "${DISTRO_VERSION}"
+
+python () {
+    ver = d.getVar('OS_VERSION', True) or 'invalid'
+    try:
+        ver = int(ver)
+    except ValueError:
+        bb.fatal("Invalid value for OS_VERSION (%s), must be a non-negative integer value." % ver)
+    if ver <= 0 or ver > 2147483647:
+        bb.fatal('OS_VERSION outside of valid range (> 0, <= 2147483647): %d' % ver)
+}