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+meta-sota
+=========
+
+This layer enables over-the-air updates with OSTree and RVI SOTA client.
+
+[OSTree](https://github.com/ostreedev/ostree) is a tool for atomic full file
+system upgrades with rollback capability. Main advantage of OSTree compared
+to traditional dual partition model is that OSTree minimizes network bandwidth
+and data storage footprint by sharing files with the same contents across file
+system deployments.
+
+[RVI SOTA client](https://github.com/advancedtelematic/rvi_sota_client) adds
+authentication and provisioning capabilities to OTA and is integrated with
+OSTree.
+
+Build
+-----
+
+With AGL you can just add agl-sota feature while configuring your build
+environment as in
+
+    source meta-agl/scripts/aglsetup.sh -m porter agl-demo agl-appfw-smack agl-devel agl-sota
+
+you can then just run
+
+    bitbake agl-demo-platform
+
+and get as a result "ostree_repo" folder in your images directory
+(tmp/deploy/images/${MACHINE}/ostree_repo) containing your OSTree repository
+with rootfs committed as an OSTree deployment, 'otaimg' bootstrap image which
+is an OSTree physical sysroot as a burnable filesystem image and optionally
+some machine-dependent live images (e.g. '*.rpi-sdimg-ota' for Raspberry Pi or
+'*.porter-sdimg-ota' Renesas Porter board).
+
+Although aglsetup.sh hooks provide reasonable defaults for SOTA-related
+variables you may want to tune some of them.
+
+SOTA-related variables in local.conf
+------------------------------------
+
+* OSTREE_REPO - path to your OSTree repository.
+  Defaults to "${DEPLOY_DIR_IMAGE}/ostree_repo"
+* OSTREE_BRANCHNAME - the branch your rootfs will be committed to.
+  Defaults to "agl-ota"
+* OSTREE_OSNAME - OS deployment name on your target device. For more
+  information about deployments and osnames see
+  [OSTree documentation](https://ostree.readthedocs.io/en/latest/manual/deployment/)
+  Defaults to "agl".
+* OSTREE_INITRAMFS_IMAGE - initramfs/initrd image that is used as a proxy while
+  booting into OSTree deployment. Do not change this setting unless you are
+  sure that your initramfs can serve as such proxy.
+* OSTREE_REMOTE_URL - when set adds pushing your ostree commit to a remote
+  repo. Defaults to an empty string.
+* OSTREE_REMOTE_USER and OSTREE_REMOTE_PASSWORD - should be set if
+  OSTREE_REMOTE_URL is set. Used to authenticate to the server set in
+  OSTREE_REMOTE_URL. Both default to an empty string.
+
+Usage
+-----
+
+### OSTree ###
+OSTree includes its own simple http server. It just exposes the whole OSTree
+repository to the network so that any remote device can pull data from it to
+device's local repository. To use OSTree http server you need OSTree installed
+on your build machine. Alternatively, you could run version built inside Yocto
+using bitbake's [devshell](http://www.openembedded.org/wiki/Devshell).
+
+To expose your repo run ostree trivial-httpd using any free port.
+
+    ostree trivial-httpd tmp/deploy/images/qemux86-64/ostree_repo -P 57556
+
+You can then run from inside your device or QEMU emulation, provided your
+network is set up correctly.
+
+    # agl-remote identifies the remote server in your local repo
+    ostree remote add --no-gpg-verify agl-remote http://192.168.7.1:57556 agl-ota
+    
+    # agl-ota is a branch name in the remote repo, set in OSTREE_BRANCHNAME
+    ostree pull agl-remote agl-ota
+    
+    # agl is OS name as set in OSTREE_OSNAME
+    ostree admin deploy --os=agl agl-remote:agl-ota
+
+After restart you should boot into the newly deployed OS image.
+
+E.g. for the raspberrypi3 you can try this sequence:
+
+    # add remote
+    ostree remote add --no-gpg-verify agl-snapshot https://download.automotivelinux.org/AGL/snapshots/master/latest/raspberrypi3/deploy/images/raspberrypi3/ostree_repo/ agl-ota
+    
+    # pull
+    ostree pull agl-snapshot agl-ota
+    
+    # deploy
+    ostree admin deploy --os=agl agl-snapshot:agl-ota
+
+### SOTA tools ###
+SOTA tools now contains only one tool, garage-push that lets you push the
+changes in OSTree repository generated by bitbake process. It communicates with
+an http server capable of querying files with HEAD requests and uploading them
+with POST requests. garage-push is used as following:
+
+    garage-push --repo=/path/to/ostree-repo --ref=mybranch --url=https://my.ostree.server/ --user=username --password=password
+
+You can set OSTREE_REMOTE_URL, OSTREE_REMOTE_USER and OSTREE_REMOTE_PASSWORD in
+your local.conf to make your build results be automatically synchronized with a
+remote server.