README: add initial readme file

Signed-off-by: Sean Cross <sean@xobs.io>

README.md

@@ -0,0 +1,47 @@
+# Ion Mobility Yocto Manifest
+
+Yocto repository to build and deploy a root filesystem image for Ion Mobility.
+
+## Prerequisites
+
+You must have all prerequisites for Yocto, plus the `repo` command.
+
+**TODO** Determine prerequisites for Yocto.
+
+You must also install [Google `repo`](https://gerrit.googlesource.com/git-repo/#install), which can be as simple as:
+
+```sh
+$ mkdir -p ~/.bin
+$ PATH="${HOME}/.bin:${PATH}"
+$ curl https://storage.googleapis.com/git-repo-downloads/repo > ~/.bin/repo
+$ chmod a+rx ~/.bin/repo
+```
+
+## Getting Started
+
+1. Clone the repository and sync it:
+
+```sh
+$ mkdir yocto
+$ cd yocto
+$ repo init -u ssh://git@github.com/Ion-Mobility-Systems/yocto-manifest.git -b main -m ion-mobility-yocto-gatesgarth.xml
+$ repo sync
+```
+
+2. Enter the Yocto environment. This must be done every time you start to work on Yocto.
+
+```sh
+$ ./enter-env.sh
+```
+
+The first time you do this, you will be prompted to accept the NXP EULA.
+
+When you are in the environment, the string `(yocto) ` is prefixed to your prompt.
+
+3. Build an image. This can be done by building any available image. For example, `ion-demo-image`:
+
+```sh
+$ bitbake ion-demo-image
+```
+
+The resulting image file in `tmp/deploy/images/gridania-evt2-soc` may be written to an SD card or otherwise inspected.

ion-mobility-yocto-gatesgarth.xml

@@ -31,10 +31,9 @@
   <project name="meta-python2" path="sources/meta-python2" remote="python2" revision="c43c29e57f16af4e77441b201855321fbd546661"/>
   <project name="meta-qt5" path="sources/meta-qt5" remote="QT5" revision="8d5672cc6ca327576a814d35dfb5d59ab24043cb"/>
   <project name="meta-rust" path="sources/meta-rust" remote="rust" revision="53bfa324891966a2daf5d36dc13d4a43725aebed"/>
-  <project name="meta-ionmobility" path="sources/meta-ionmobility" remote="ionmobilitysystems" revision="8b2ff1fb59cfbe8b43b0426766a217a492806047">
+  <project name="meta-ionmobility" path="sources/meta-ionmobility" remote="ionmobilitysystems" revision="0b059427325021dbd0fd73d1725c59e6375a3e9d">
     <linkfile src="tools/ion-setup-release.sh" dest="ion-setup-release.sh"/>
     <linkfile src="tools/enter-env.sh" dest="enter-env.sh"/>
-    <!--<linkfile src="README" dest="README-IMXBSP"/>-->
   </project>
   <project name="meta-flutter" path="sources/meta-flutter" remote="jwinarske" revision="a794c540ea61d1b48613a4c28105d109e061a339"/>
   <project name="meta-timesys" path="sources/meta-timesys" remote="Timesys" revision="00f81fbdf7fba2a09ff83d14fc3b040e9ae63b42"/>