Add content to README.md (#9)

.github/workflows/ci.yml

@@ -76,3 +76,18 @@ jobs:
         run: |
           git-secrets --register-aws
           git-secrets --scan
+  link-verifier:
+    runs-on: ubuntu-18.04
+    steps:
+      - uses: actions/checkout@v2
+      - name: Setup Python for link verifier action
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.8'
+      - name: Check Links
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        uses: FreeRTOS/CI-CD-GitHub-Actions/link-verifier@main
+        with:
+          path: ./
+          include-file-types: .c,.h,.dox

README.md

@@ -1,44 +1,67 @@
 ## coreSNTP Library
 
-This repository contains the coreSNTP library, a client library to use the Simple Network Time Protocol (SNTP), that is specified in [RFC 4330](https://tools.ietf.org/html/rfc4330), to synchronize client devices with network time.
-According to the SNTPv4 specification, "_To an NTP or SNTP server, NTP and SNTP clients are indistinguishable; to an NTP or SNTP client, NTP and SNTP servers are indistinguishable._", thereby, allowing SNTP clients to request time from NTP servers. 
+**Note:** This library is under development.
 
-## Reference example
+This repository contains the coreSNTP library, a client library to use Simple Network Time Protocol (SNTP) to synchronize device clocks with internet time. This library implements the SNTPv4 specification defined in [RFC 4330](https://tools.ietf.org/html/rfc4330).
 
+An SNTP client can request time from both NTP and SNTP servers. According to the SNTPv4 specification, "_To an NTP or SNTP server, NTP and SNTP clients are indistinguishable; to an NTP or SNTP client, NTP and SNTP servers are indistinguishable._", thereby, allowing SNTP clients to request time from NTP servers. 
+
+## Cloning this repository
+This repo uses [Git Submodules](https://git-scm.com/book/en/v2/Git-Tools-Submodules) to bring in dependent components.
+
+To clone using HTTPS:
+```
+git clone https://github.com/FreeRTOS/coreSNTP.git --recurse-submodules
+```
+Using SSH:
+```
+git clone [email protected]:FreeRTOS/coreSNTP.git --recurse-submodules
+```
+
+If you have downloaded the repo without using the `--recurse-submodules` argument, you need to run:
+```
+git submodule update --init --recursive
+```
 
 ## Building the library
 
-## Building unit tests
+You can build the coreSNTP source files that are in the [source](source/) directory, and add [source/include](source/include) to your compiler's include path.
+
+If using CMake, the [coreSntpFilePaths.cmake](coreSntpFilePaths.cmake) file contains the above information of the source files and the header include path from this repository.
+
+## Building Unit Tests
 
-### Checkout Unity Submodule
-By default, the submodules in this repository are configured with `update=none` in [.gitmodules](.gitmodules), to avoid increasing clone time and disk space usage of other repositories (like [amazon-freertos](https://github.com/aws/amazon-freertos) that submodules this repository).
+### Checkout CMock Submodule
 
-To build unit tests, the submodule dependency of Unity is required. Use the following command to clone the submodule:
+To build unit tests, the submodule dependency of CMock is required. Use the following command to clone the submodule:
 ```
-git submodule update --checkout --init --recursive --test/unit-test/Unity
+git submodule update --checkout --init --recursive test/unit-test/CMock
 ```
 
-### Platform Prerequisites
+### Unit Test Platform Prerequisites
 
 - For running unit tests
-    - C89 or later compiler like gcc
-    - CMake 3.13.0 or later
-- For running the coverage target, gcov is additionally required.
+    - **C90 compiler** like gcc
+    - **CMake 3.13.0 or later**
+    - **Ruby 2.0.0 or later** is additionally required for the CMock test framework (that we use).
+- For running the coverage target, **gcov** and **lcov** are additionally required.
 
-### Steps to build Unit Tests
+### Steps to build **Unit Tests**
 
-1. Go to the root directory of this repository. (Make sure that the **Unity** submodule is cloned as described [above](#checkout-unity-submodule).)
+1. Go to the root directory of this repository. (Make sure that the **CMock** submodule is cloned as described [above](#checkout-cmock-submodule))
 
-1. Create build directory: `mkdir build && cd build`
+1. Run the *cmake* command: `cmake -S test -B build`
 
-1. Run *cmake* while inside build directory: `cmake -S ../test`
-
-1. Run this command to build the library and unit tests: `make all`
+1. Run this command to build the library and unit tests: `make -C build all`
 
 1. The generated test executables will be present in `build/bin/tests` folder.
 
-1. Run `ctest` to execute all tests and view the test run summary.
+1. Run `cd build && ctest` to execute all tests and view the test run summary.
 
 ## Contributing
 
 See [CONTRIBUTING.md](./.github/CONTRIBUTING.md) for information on contributing.
+
+## License
+
+This library is licensed under the MIT License. See the [LICENSE](LICENSE) file.