Add a Getting Started guide to CKW README

Resolves: COMPMID-6299

Change-Id: I3b9c464e8cdc6c081472ec0aa6b738c7ccb18b49
Signed-off-by: Jakub Sujak <jakub.sujak@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/9759
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Gian Marco Iodice <gianmarco.iodice@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 57 insertions, 13 deletions

diff --git a/compute_kernel_writer/README.md b/compute_kernel_writer/README.md
index 951e6bea6b..8a24fe20ec 100644
--- a/compute_kernel_writer/README.md
+++ b/compute_kernel_writer/README.md
@@ -1,42 +1,86 @@
 # Compute Kernel Writer
 
-Project description to follow.
+Compute Kernel Writer is a tile-based, just-in-time code writer for deep learning and computer vision applications.
+This tool offers a C++ interface to allow developers to write functions without a return type (called "kernels")
+using their preferred programming language (at the moment, only OpenCL is supported). 
+The library is specifically designed to be lightweight and to offer an intuitive API for efficient code writing.
 
 ## Getting started
 
+The fastest way to get started with Compute Kernel Writer is to build and run the test suite.
+The following subsections show you how to do this.
+
+### Dependencies
+
+This project requires the following dependencies, obtainable via your preferred package manager, to be installed and available on your system.
+
+* `build-essential`
+* `cmake >= 3.14`
+* (Optional) `ninja-build`
+
+In addition, the guide makes use of the following toolchains:
+
+* (Optional) `Arm GNU toolchain` available to download from the [Arm Developer](https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads) website
+* (Optional) `Android NDK toolset` available to download from the [Android Developer](https://developer.android.com/ndk/downloads/index.html) website
 
 ### Building and running tests
 
-The fastest way to get started with Compute Kernel Writer is to build and run the test suite.
+#### Native compilation
 
-#### Compile natively on Linux x86_64
+You can quickly compile the library on your computer by using the following commands:
 
 ```shell
-mkdir build && cd build
-CC=gcc CXX=g++ cmake -G Ninja -DBUILD_SHARED_LIBS=ON -DCMAKE_BUILD_TYPE=Release -DCKW_ENABLE_OPENCL=ON -DCKW_ENABLE_ASSERTS=ON -DCKW_BUILD_TESTING=ON ..
+mkdir -p build && cd build
+CXX=g++ cmake -G Ninja -DBUILD_SHARED_LIBS=ON -DCMAKE_BUILD_TYPE=Release -DCKW_ENABLE_OPENCL=ON -DCKW_ENABLE_ASSERTS=ON -DCKW_BUILD_TESTING=ON -S ..
 cmake --build .
 ```
 
-#### Cross-compile to Linux aarch64
+The preceding commands build the library in release mode (`-DCMAKE_BUILD_TYPE=Release`) and targets OpenCL code generation (`-DCKW_ENABLE_OPENCL=ON`). 
+In addition, code assertions are enabled (`-DCKW_ENABLE_ASSERTS=ON`) and the test suite is built (`-DCKW_BUILD_TESTING=ON`). 
+Alternatively, choose to build a static instead of a shared library by setting `-DBUILD_SHARED_LIBS=OFF`.
+
+#### Cross-compile to Linux AArch64
+
+The Arm GNU toolchain can be used to cross-compile the project to a Linux system with an AArch64 processor, like a Raspberry Pi, using an x86_64 Linux host machine.
 
 ```shell
-mkdir build && cd build
-cmake -G Ninja -DBUILD_SHARED_LIBS=ON -DCMAKE_BUILD_TYPE=Release -DCKW_ENABLE_OPENCL=ON -DCKW_ENABLE_ASSERTS=ON -DCKW_BUILD_TESTING=ON -DCMAKE_TOOLCHAIN_FILE=../cmake/toolchains/gcc_linux_aarch64.toolchain.cmake ..
+mkdir -p build && cd build
+CXX=aarch64-none-linux-gnu-g++ cmake -G Ninja -DBUILD_SHARED_LIBS=ON -DCMAKE_BUILD_TYPE=Release -DCKW_ENABLE_OPENCL=ON -DCKW_ENABLE_ASSERTS=ON -DCKW_BUILD_TESTING=ON -S ..
 cmake --build .
 ```
 
-#### Cross-compile to Android aarch64
+The build configuration is identical to the previous step but now requires specifying the target triple in the CXX compiler (`CXX=aarch64-none-linux-gnu-g++`) to generate binaries for the target platform.
+
+#### Cross-compile to Android AArch64
 
-Cross-compiling to the Android platform requires the toolchain CMake file downloaded in the [Android NDK](https://developer.android.com/ndk).
+Cross-compiling for Android systems requires the Android NDK toolset. The downloaded NDK contains the toolchain file necessary for cross-compiling the project.
 
 ```shell
-mkdir build && cd build
-cmake -G Ninja -DBUILD_SHARED_LIBS=ON -DCMAKE_BUILD_TYPE=Release -DCKW_ENABLE_OPENCL=ON -DCKW_ENABLE_ASSERTS=ON -DCKW_BUILD_TESTING=ON -DCMAKE_TOOLCHAIN_FILE=<NDK>/build/cmake/android.toolchain.cmake ..
+mkdir -p build && cd build
+cmake -G Ninja -DBUILD_SHARED_LIBS=ON -DCMAKE_BUILD_TYPE=Release -DCKW_ENABLE_OPENCL=ON -DCKW_ENABLE_ASSERTS=ON -DCKW_BUILD_TESTING=ON -DCMAKE_TOOLCHAIN_FILE=<NDK>/build/cmake/android.toolchain.cmake -S ..
 cmake --build .
 ```
 
-#### Run the validation suite
+This build re-uses the same build configuration as before, but this time does not require specifying the CXX compiler as this (and other target-specific information) is handled by the toolchain file (`-DCMAKE_TOOLCHAIN_FILE`).
+
+#### Run the validation test suite
+
+Confirm the project has been built successfully by running the validation test suite.
 
 ```shell
 ./ckw_validation
 ```
+
+### List of build options
+
+This project can be configured with the following build options. Enable options by passing them to the CMake command, preceded with `-D`.
+
+| Option               | Description                                                                                                                               |
+|:---------------------|:------------------------------------------------------------------------------------------------------------------------------------------|
+| BUILD_SHARED_LIBS    | Controls whether to build static or shared libraries.                                                                                     |
+| CMAKE_BUILD_TYPE     | The project build type or configuration. Choose from Release or Debug. <br/>The release build will always build for smallest binary size. |
+| CKW_ENABLE_OPENCL    | Enable OpenCL code generation.                                                                                                            |
+| CKW_ENABLE_ASSERTS   | Enable assertions. Always enabled for Debug builds.                                                                                       |
+| CKW_BUILD_TESTING    | Build the validation test suite.                                                                                                          |
+| CKW_CCACHE           | Use compiler cache for faster recompilation.                                                                                              |
+| CMAKE_TOOLCHAIN_FILE | When cross-compiling, set this variable to the path of the CMake toolchain file.                                                          |