MLECO-1860: Support for Arm GNU Embedded Toolchain

This patch enables compilation of ML use cases bare-metal applications
using Arm GNU Embedded Toolchain. The GNU toolchain can be used instead
of the Arm Compiler that was already supported.

The GNU toolchain is also set as the default toolchain when building
applications for the MPS3 target.

Note: The version of GNU toolchain must be 10.2.1 or higher.

Change-Id: I5fff242f0f52d2db6c75d292f9fa990df1aec978
Signed-off-by: Kshitij Sisodia <kshitij.sisodia@arm.com>

1 files changed, 26 insertions, 79 deletions

diff --git a/docs/use_cases/img_class.md b/docs/use_cases/img_class.md
index 0102409..68a5285 100644
--- a/docs/use_cases/img_class.md
+++ b/docs/use_cases/img_class.md
@@ -1,16 +1,17 @@
 # Image Classification Code Sample
 
-- [Introduction](#introduction)
-  - [Prerequisites](#prerequisites)
-- [Building the code sample application from sources](#building-the-code-sample-application-from-sources)
-  - [Build options](#build-options)
-  - [Build process](#build-process)
-  - [Add custom input](#add-custom-input)
-  - [Add custom model](#add-custom-model)
-- [Setting-up and running Ethos-U55 code sample](#setting-up-and-running-ethos-u55-code-sample)
-  - [Setting up the Ethos-U55 Fast Model](#setting-up-the-ethos-u55-fast-model)
-  - [Starting Fast Model simulation](#starting-fast-model-simulation)
-  - [Running Image Classification](#running-image-classification)
+- [Image Classification Code Sample](#image-classification-code-sample)
+  - [Introduction](#introduction)
+    - [Prerequisites](#prerequisites)
+  - [Building the code sample application from sources](#building-the-code-sample-application-from-sources)
+    - [Build options](#build-options)
+    - [Build process](#build-process)
+    - [Add custom input](#add-custom-input)
+    - [Add custom model](#add-custom-model)
+  - [Setting-up and running Ethos-U55 code sample](#setting-up-and-running-ethos-u55-code-sample)
+    - [Setting up the Ethos-U55 Fast Model](#setting-up-the-ethos-u55-fast-model)
+    - [Starting Fast Model simulation](#starting-fast-model-simulation)
+    - [Running Image Classification](#running-image-classification)
 
 ## Introduction
 
@@ -76,72 +77,24 @@ On Linux, execute the following command to build **only** Image Classification a
 Model when providing only the mandatory arguments for CMake configuration:
 
 ```commandline
-cmake \
-    -DTARGET_PLATFORM=mps3 \
-    -DTARGET_SUBSYSTEM=sse-300 \
-    -DCMAKE_TOOLCHAIN_FILE=./scripts/cmake/bare-metal-toolchain.cmake \
-    -DUSE_CASE_BUILD=img_class ..
+cmake ../ -DUSE_CASE_BUILD=img_class
 ```
 
-Toolchain option `CMAKE_TOOLCHAIN_FILE` points to the toolchain specific file to set the compiler and platform specific
-parameters.
-
 To configure a build that can be debugged using Arm-DS, we can just specify
-the build type as `Debug`:
+the build type as `Debug` and use the `Arm Compiler` toolchain file:
 
 ```commandline
-cmake \
-    -DTARGET_PLATFORM=mps3 \
-    -DTARGET_SUBSYSTEM=sse-300 \
-    -DCMAKE_TOOLCHAIN_FILE=scripts/cmake/bare-metal-toolchain.cmake \
+cmake .. \
+    -DCMAKE_TOOLCHAIN_FILE=scripts/cmake/toolchains/bare-metal-armclang.cmake \
     -DCMAKE_BUILD_TYPE=Debug \
-    -DUSE_CASE_BUILD=img_class ..
-```
-
-To configure a build that can be debugged using a tool that only supports
-DWARF format 3 (Modeldebugger for example), we can use:
-
-```commandline
-cmake \
-    -DTARGET_PLATFORM=mps3 \
-    -DTARGET_SUBSYSTEM=sse-300 \
-    -DCMAKE_TOOLCHAIN_FILE=scripts/cmake/bare-metal-toolchain.cmake \
-    -DCMAKE_BUILD_TYPE=Debug \
-    -DARMCLANG_DEBUG_DWARF_LEVEL=3 \
-    -DUSE_CASE_BUILD=img_class ..
-```
-
-> **Note:** If building for different Ethos-U55 configurations, see
->[Configuring build for different Arm Ethos-U55 configurations](../sections/building.md#Configuring-build-for-different-Arm-Ethos-U55-configurations):
-
-If the TensorFlow source tree is not in its default expected location,
-set the path using `TENSORFLOW_SRC_PATH`.
-Similarly, if the Ethos-U55 driver is not in the default location,
-`ETHOS_U55_DRIVER_SRC_PATH` can be used to configure the location. For example:
-
-```commandline
-cmake \
-    -DTARGET_PLATFORM=mps3 \
-    -DTARGET_SUBSYSTEM=sse-300 \
-    -DCMAKE_TOOLCHAIN_FILE=scripts/cmake/bare-metal-toolchain.cmake \
-    -DTENSORFLOW_SRC_PATH=/my/custom/location/tensorflow \
-    -DETHOS_U55_DRIVER_SRC_PATH=/my/custom/location/core_driver \
-    -DUSE_CASE_BUILD=img_class ..
+    -DUSE_CASE_BUILD=img_class
 ```
 
-Also, `CMSIS_SRC_PATH` parameter can be used to override the CMSIS sources used for compilation used by TensorFlow by
-default. For example, to use the CMSIS sources fetched by the ethos-u helper script, we can use:
-
-```commandline
-cmake \
-    -DTARGET_PLATFORM=mps3 \
-    -DTARGET_SUBSYSTEM=sse-300 \
-    -DCMAKE_TOOLCHAIN_FILE=scripts/cmake/bare-metal-toolchain.cmake \
-    -DTENSORFLOW_SRC_PATH=../ethos-u/core_software/tensorflow \
-    -DETHOS_U55_DRIVER_SRC_PATH=../ethos-u/core_software/core_driver \
-    -DCMSIS_SRC_PATH=../ethos-u/core_software/cmsis \
-    -DUSE_CASE_BUILD=img_class ..
-```
+Also see:
+- [Configuring with custom TPIP dependencies](../sections/building.md#Configuring-with-custom-TPIP-dependencies)
+- [Using Arm Compiler](../sections/building.md#using-arm-compiler)
+- [Configuring the build for simple_platform](../sections/building.md#Configuring-the-build-for-simple_platform)
+- [Working with model debugger from Arm FastModel Tools](../sections/building.md#Working-with-model-debugger-from-Arm-FastModel-Tools)
 
 > **Note:** If re-building with changed parameters values, it is highly advised to clean the build directory and re-run
 >the CMake command.
@@ -200,12 +153,9 @@ cp custom_image1.bmp /tmp/custom_images/
 Next set `img_class_FILE_PATH` to the location of this folder when building:
 
 ```commandline
-cmake \
+cmake .. \
     -Dimg_class_FILE_PATH=/tmp/custom_images/ \
-    -DTARGET_PLATFORM=mps3 \
-    -DTARGET_SUBSYSTEM=sse-300 \
-    -DCMAKE_TOOLCHAIN_FILE=scripts/cmake/bare-metal-toolchain.cmake \
-    -DUSE_CASE_BUILD=img_class ..
+    -DUSE_CASE_BUILD=img_class
 ```
 
 The images found in the `img_class_FILE_PATH` folder will be picked up and automatically converted to C++ files during
@@ -249,13 +199,10 @@ Then, you must set `img_class_MODEL_TFLITE_PATH` to the location of the Vela pro
 An example:
 
 ```commandline
-cmake \
+cmake .. \
     -Dimg_class_MODEL_TFLITE_PATH=<path/to/custom_model_after_vela.tflite> \
     -Dimg_class_LABELS_TXT_FILE=<path/to/labels_custom_model.txt> \
-    -DTARGET_PLATFORM=mps3 \
-    -DTARGET_SUBSYSTEM=sse-300 \
-    -DCMAKE_TOOLCHAIN_FILE=scripts/cmake/bare-metal-toolchain.cmake \
-    -DUSE_CASE_BUILD=img_class ..
+    -DUSE_CASE_BUILD=img_class
 ```
 
 > **Note:** Clean the build directory before re-running the CMake command.