Merge branch 'develop' of JF/PineTime into master

1 files changed, 56 insertions, 16 deletions

diff --git a/doc/buildWithDocker.md b/doc/buildWithDocker.md
index 705c6d9..7a2f372 100644
--- a/doc/buildWithDocker.md
+++ b/doc/buildWithDocker.md
@@ -1,33 +1,73 @@
 # Build the project using Docker
-A [Docker image (Dockerfile)](../docker) containing all the build environment is available for X86_64 and AMD64 architectures. This image makes the build of the firmware and the generation of the DFU file for OTA.
 
-## Build the image
-The image is not (yet) available on DockerHub, you need to build it yourself, which is quite easy. The following commands must be run from the root of the project.
+A [Docker image (Dockerfile)](../docker) containing all the build environment is available for X86_64 and AMD64 architectures. These images make the build of the firmware and the generation of the DFU file for OTA quite easy, as well as preventing clashes with any other toolchains or development environments you may have installed.
+
+Based on Ubuntu 18.04 with the following build dependencies:
+
+* ARM GCC Toolchain
+* nRF SDK
+* MCUBoot
+* adafruit-nrfutil
+
+## Run a container to build the project
+
+The `infinitime-build` image contains all the dependencies you need. The default `CMD` will compile sources found in `/sources`, so you need only mount your code. 
+
+This example  will build the firmware, generate the MCUBoot image and generate the DFU file. Outputs will be written to **<project_root>/build/output**:
 
-If you are running on a x86_64 computer : 
+```bash
+cd <project_root> # e.g. cd ./work/Pinetime
+docker run --rm -it -v $(pwd):/sources infinitime-build
 ```
-docker image build -t infinitime-build --build-arg USER_ID=$(id -u) --build-arg GROUP_ID=$(id -g) docker/x86_64/
+
+If you only want to build a single CMake target, you can pass it in as the first parameter to the build script. This means calling the script explicitly as it will override the `CMD`. Here's an example For `pinetime-app`:
+
+```bash
+docker run --rm -it -v $(pwd):/sources infinitime-build /opt/build.sh pinetime-app
 ```
 
-And if your are running on an ARM64 device (tested on RaspberryPi4 and Pine64 PineBookPro):
+The image is built using 1000:1000 for the user id and group id. If this is different to your user or group ids (run `id -u` and `id -g` to find out what your id values are if you are unsure), you will need to override them via the `--user` parameter in order to prevent permission errors with the output files (and the cmake build cache).
+
+Running with this image is the same as above, you just specify the ids to `docker run`
+
+```bash
+docker run --rm -it -v $(pwd):/sources --user $(id -u):$(id -g) pfeerick/infinitime-build
 ```
-docker image build -t infinitime-build --build-arg USER_ID=$(id -u) --build-arg GROUP_ID=$(id -g) docker/arm64/
+
+Or you can specify your user id and group id (by number, not by name) directly:
+
+```bash
+docker run --rm -it -v $(pwd):/sources --user 1234:1234 infinitime-build
 ```
 
-This operation will take some time. It builds a Docker image based on Ubuntu, install some packages, download the ARM toolchain, the NRF SDK, MCUBoot and adafruit-nrfutil.
+## Using the image from Docker Hub
 
-When this is done, a new image named *infinitime-build* is available.
+The image is avaiable via Docker Hub for both the amd64 and arm64v8 architectures at [pfeerick/infinitime-build](https://hub.docker.com/repository/docker/pfeerick/infinitime-build).
 
-## Run a container to build the project:
+It can be pulled (downloaded) using the following command:
 
-```
-docker run --rm -v <project_root>:/sources infinitime-build
+```bash
+docker pull pfeerick/infinitime-build
 ```
 
-Replace *<project_root>* by the path of the root of the project on your computer. For example:
+The default `latest` tag *should* automatically identify the correct image architecture, but if for some reason Docker does not, you can specify it manually:
 
-```
-docker run --rm -v /home/jf/git/PineTime:/sources infinitime-build
+* For AMD64 (x86_64) systems: `docker pull pfeerick/infinitime-build:amd64`
+
+* For ARM64v8 (ARM64/aarch64) systems: `docker pull pfeerick/infinitime-build:arm64v8`
+
+## Build the image
+
+You can build the image yourself if you like!
+
+The following commands must be run from the root of the project. This operation will take some time but, when done, a new image named *infinitime-build* is available.
+
+```bash
+docker image build -t infinitime-build ./docker
 ```
 
-This will start a container, build the firmware and generate the MCUBoot image and the DFU file. The output of the build is stored in **<project_root>/built/output**.
\ No newline at end of file
+The `PUID` and `PGID` build arguments are used to set the user and group ids used in the container, meaning you will not need to specify it later unless they change for some reason. Specifying them is not mandatory, as this can be over-ridden at build time via the `--user` flag, but doing so will make the command you need to run later a bit shorter. In the below examples, they are set to your current user id and group id automatically. You can specify them manually, but they must be specified by number, not by name.
+
+```bash
+docker image build -t infinitime-build --build-arg PUID=$(id -u) --build-arg PGID=$(id -g) ./docker
+```