README: autoupdater

README.md

@@ -36,11 +36,36 @@ be done when only patches have changed), but doesn't rebuild the toolchain unnec
 So all in all, to update and rebuild a Gluon build tree, the following commands should be used:
 
     git pull
+    (cd site && git pull)
     make update
     make cleanall
     make
 
 
+# The autoupdater
+
+Gluon contains an automatic update system which can be configured in the site configuration.
+
+By default, the autoupdater is disabled (as it is usually not helpful to have unexpected updates
+during development), but it can be enabled by setting the variable GLUON_BRANCH when building
+to override the default branch set in the set in the site configuration.
+
+A manifest file for the updater can be generated with `make manifest`. A signing script (using
+ecdsautils) can by found in the `contrib` directory.
+
+A fully automated nightly build could use the following commands:
+
+    git pull
+    (cd site && git pull)
+    make update
+    make cleanall
+    make -j5 GLUON_BRANCH=experimental
+    make manifest GLUON_BRANCH=experimental
+    contrib/sign.sh $SECRETKEY images/sysupgrade/experimental.manifest
+    cp -r images /where/to/put/this/experimental
+    mv /where/to/put/this/experimental/experimental.manifest /where/to/put/this/experimental/manifest
+
+
 # Development
 
 **Gluon IRC channel: `#gluon` in hackint**