general polishing and clarification of text

1 files changed, 37 insertions, 33 deletions

diff --git a/README.adoc b/README.adoc
index d7a8fbb..f8e8ada 100644
--- a/README.adoc
+++ b/README.adoc
@@ -1,46 +1,50 @@
 = meta-updater
 
-This layer enables over-the-air updates with OSTree and RVI SOTA client.
+This layer enables over-the-air updates (OTA) with https://github.com/ostreedev/ostree[OSTree] and https://github.com/advancedtelematic/rvi_sota_client[RVI SOTA client].
 
-https://github.com/ostreedev/ostree[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.
+https://github.com/ostreedev/ostree[OSTree] is a tool for atomic full file system upgrades with rollback capability. OSTree has several advantages over traditional dual-bank systems, but the most important one is that it minimizes network bandwidth and data storage footprint by sharing files with the same contents across file system deployments.
 
-https://github.com/advancedtelematic/rvi_sota_client[RVI SOTA client] adds authentication and provisioning capabilities to OTA and is integrated with OSTree.
+https://github.com/advancedtelematic/rvi_sota_client[RVI SOTA client] adds authentication and provisioning capabilities to OTA and is integrated with OSTree. It connects to https://github.com/advancedtelematic/rvi_sota_server[RVI SOTA server].
 
 == Build
 
 === Quickstart
 
-https://github.com/advancedtelematic/garage-quickstart-rpi[ATS Garage Quickstart] is an example yocto-based project combining stadard poky distribution with OSTree capabilities. For detailed getting started tutorial see https://github.com/advancedtelematic/garage-quickstart-rpi/blob/master/README.adoc[README].
+If you don't already have a Yocto project that you want to add OTA to, you can use the https://github.com/advancedtelematic/garage-quickstart-rpi[ATS Garage Quickstart] project to rapidly get up and running on a Raspberry Pi. It takes a standard https://www.yoctoproject.org/tools-resources/projects/poky[poky] distribution, and adds OTA and OSTree capabilities. For a detailed getting started tutorial see the https://github.com/advancedtelematic/garage-quickstart-rpi/blob/master/README.adoc[README].
 
 === Adding meta-updater capabilities to your build
 
-If you already have a Yocto-base project and you want to add atomic filesystem updates to it you need to do just three things:
+If you already have a Yocto-based project and you want to add atomic filesystem updates to it, you just need to do three things:
 
-1.  Clone meta-updater layer and add it to your https://www.yoctoproject.org/docs/2.1/ref-manual/ref-manual.html#structure-build-conf-bblayers.conf[conf/bblayers.conf].
-2.  Clone BSP integration layer (meta-updater-$\{PLATFORM}, e.g. meta-updater-raspberrypi) and add it to your conf/bblayers.conf. If your board isn't yet supported, you could write BSP integration work yourself. See <<Supported boards>> section for the details.
-3.  Set up your https://www.yoctoproject.org/docs/2.1/ref-manual/ref-manual.html#var-DISTRO[distro]. If you are using "poky", the default distro in Yocto, you can change it in your conf/local.conf to "poky-sota". Alternatively if you are using your own or third party distro configuration, you can add 'require conf/distro/sota.conf.inc' to it, thus combining capabilities of your distro with meta-updater features.
+1.  Clone the `meta-updater` layer and add it to your https://www.yoctoproject.org/docs/2.1/ref-manual/ref-manual.html#structure-build-conf-bblayers.conf[bblayers.conf].
+2.  Clone BSP integration layer (meta-updater-$\{PLATFORM}, e.g. https://github.com/advancedtelematic/meta-updater-raspberrypi[meta-updater-raspberrypi]) and add it to your conf/bblayers.conf. If your board isn't supported yet, you could write a BSP integration for it yourself. See the <<Adding support for your board>> section for the details.
+3.  Set up your https://www.yoctoproject.org/docs/2.1/ref-manual/ref-manual.html#var-DISTRO[distro]. If you are using "poky", the default distro in Yocto, you can change it in your conf/local.conf to "poky-sota". Alternatively, if you are using your own or third party distro configuration, you can add 'require conf/distro/sota.conf.inc' to it, thus combining capabilities of your distro with meta-updater features.
 
-You can then build your image as usual (bitbake ). After building the root file system bitbake will then create an https://ostree.readthedocs.io/en/latest/manual/adapting-existing/[OSTree-enabled version] of it, commit it to your local OSTree repo and optionally push it to a remote server. Additionally a live disk image will be created (normally named $\{IMAGE_NAME}.-sdimg-ota e.g. core-image-raspberrypi3.rpi-sdimg-ota). You can control this behaviour though <<SOTA-related variables in local.conf,OSTree-related variables in your local.conf>>.
+You can then build your image as usual, with bitbake. After building the root file system, bitbake will then create an https://ostree.readthedocs.io/en/latest/manual/adapting-existing/[OSTree-enabled version] of it, commit it to your local OSTree repo and (optionally) push it to a remote server. Additionally, a live disk image will be created (normally named $\{IMAGE_NAME}.-sdimg-ota e.g. core-image-raspberrypi3.rpi-sdimg-ota). You can control this behaviour through <<variables in your local.conf,OSTree-related variables in your local.conf>>.
 
 === Build with OpenIVI
 
 === Build in AGL
 
-With AGL you can just add agl-sota feature while configuring your build environment as in
+With AGL you can just add agl-sota feature while configuring your build environment:
 
 ....
 source meta-agl/scripts/aglsetup.sh -m porter agl-demo agl-appfw-smack agl-devel agl-sota
 ....
 
-you can then just run
+you can then run
 
 ....
 bitbake agl-demo-platform
 ....
 
-and get as a result "ostree_repo" folder in your images directory (tmp/deploy/images/$\{MACHINE}/ostree_repo) containing your OSTree repository with rootfs committed as an OSTree deployment, 'otaimg' bootstrap image which is an OSTree physical sysroot as a burnable filesystem image and optionally some machine-dependent live images (e.g. '_.rpi-sdimg-ota' for Raspberry Pi or '_.porter-sdimg-ota' Renesas Porter board).
+and get as a result an "ostree_repo" folder in your images directory (tmp/deploy/images/$\{MACHINE}/ostree_repo). It will contain
 
-Although aglsetup.sh hooks provide reasonable defaults for SOTA-related variables you may want to tune some of them.
+* your OSTree repository, with the rootfs committed as an OSTree deployment,
+* an '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.
 
 == Supported boards
 
@@ -52,51 +56,51 @@ Currently supported platforms are
 
 === Adding support for your board
 
-If your board isn't yet supported you can add board integration code yourself. The main purpose of this code is to provide a bootloader that will get use of https://ostree.readthedocs.io/en/latest/manual/atomic-upgrades/[OSTree's boot directory] In meta-updater integration layers finished so far it is done by
+If your board isn't supported yet, you can add board integration code yourself. The main purpose of this code is to provide a bootloader that will be able to use https://ostree.readthedocs.io/en/latest/manual/atomic-upgrades/[OSTree's boot directory]. In the meta-updater integration layers we have written so far, the basic steps are:
 
-1.  Making the board boot into http://www.denx.de/wiki/U-Boot[U-Boot]
-2.  Making U-boot import variables from /boot/loader/uEnv.txt and load the kernel with initramfs and kernel command line arguments according to what is set this file.
+1.  Make the board boot into http://www.denx.de/wiki/U-Boot[U-Boot]
+2.  Make U-boot import variables from /boot/loader/uEnv.txt and load the kernel with initramfs and kernel command line arguments according to what is set in this file.
 
 You may take a look into https://github.com/advancedtelematic/meta-updater-minnowboard[Minnowboard] or https://github.com/advancedtelematic/meta-updater-raspberrypi[Raspberry Pi] integration layers for examples.
 
-It is still possible to make other loaders work with OSTree as well.
+Although we have used U-Boot so far, other boot loaders can be configured work with OSTree as well.
 
 == 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 "ota"
-* OSTREE_OSNAME - OS deployment name on your target device. For more information about deployments and osnames see https://ostree.readthedocs.io/en/latest/manual/deployment/[OSTree documentation] Defaults to "poky".
-* 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_PUSH_CREDENTIALS - when set adds pushing your ostree commit to a remote repo. sota-tools will then use credentials in the file pointed to by this variable.
+* OSTREE_OSNAME - OS deployment name on your target device. For more information about deployments and osnames see the https://ostree.readthedocs.io/en/latest/manual/deployment/[OSTree documentation]. Defaults to "poky".
+* 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 a proxy.
+* OSTREE_PUSH_CREDENTIALS - when set, your ostree commit will be pushed to a remote repo as a bitbake step. This should be the path to a JSON credentials file in https://github.com/advancedtelematic/sota-tools#credentials[the format accepted by garage-push].
 
 == 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 http://www.openembedded.org/wiki/Devshell[devshell].
+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 the OSTree http server, you will need OSTree installed on your build machine. (Alternatively, you could run version built inside Yocto using bitbake's http://www.openembedded.org/wiki/Devshell[devshell].)
 
-To expose your repo run ostree trivial-httpd using any free port.
+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.
+You can then run ostree from inside your device by adding your repo:
 
 ....
 # 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
+ostree remote add --no-gpg-verify my-remote http://192.168.7.1:57556 ota
 
-# agl-ota is a branch name in the remote repo, set in OSTREE_BRANCHNAME
-ostree pull agl-remote agl-ota
+# ota is a branch name in the remote repo, set in OSTREE_BRANCHNAME
+ostree pull my-remote ota
 
-# agl is OS name as set in OSTREE_OSNAME
-ostree admin deploy --os=agl agl-remote:agl-ota
+# poky is OS name as set in OSTREE_OSNAME
+ostree admin deploy --os=poky my-remote:ota
 ....
 
-After restart you should boot into the newly deployed OS image.
+After restarting, you will boot into the newly deployed OS image.
 
-E.g. for the raspberrypi3 you can try this sequence:
+For example, on the raspberry pi you can try this sequence:
 
 ....
 # add remote
@@ -111,10 +115,10 @@ 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:
+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. In particular, this can be used with http://www.atsgarage.com/[ATS Garage]. garage-push is used as follws:
 
 ....
-garage-push --repo=/path/to/ostree-repo --ref=mybranch --credentials=~/.sota-tools.json --user=username --password=
+garage-push --repo=/path/to/ostree-repo --ref=mybranch --credentials=/path/to/credentials.json
 ....
 
-You can set OSTREE_PUSH_CREDENTIALS in your local.conf to make your build results be automatically synchronized with a remote server. Credentials are stored in JSON format which is described in https://github.com/advancedtelematic/sota-tools/blob/master/README.adoc[sota-tools documentation]
+You can set OSTREE_PUSH_CREDENTIALS in your local.conf to make your build results be automatically synchronized with a remote server. Credentials are stored in the JSON format described in the https://github.com/advancedtelematic/sota-tools#credentials[sota-tools README].