1. Prerequisite¶

This document describes the software requirements for building RMM for AArch64 target platforms.

It may possible to build RMM with combinations of software packages that are different from those listed below, however only the software described in this document can be officially supported.

2. Build Host¶

The RMM officially supports a limited set of build environments and setups. In this context, official support means that the environments listed below are actively used by team members and active developers, hence users should be able to recreate the same configurations by following the instructions described below. In case of problems, the RMM team provides support only for these environments, but building in other environments can still be possible.

We recommend at least Ubuntu 20.04 LTS (x64) for build environment. The arm64/AArch64 Ubuntu and other Linux distributions should also work fine, provided that the necessary tools and libraries can be installed.

3. Tool & Dependency overview¶

The following tools are required to obtain and build RMM:

Tool dependencies¶
Name	Version	Component
C compiler	see Setup Toolchain	Firmware
CMake	>=3.15.0	Firmware, Documentation
GNU Make	>4.0	Firmware, Documentation
Python	3.x	Firmware, Documentation
Perl	>=5.26	Firmware, Documentation
ninja-build		Firmware (using Ninja Generator)
Sphinx	>=2.4,<3.0.0	Documentation
sphinxcontrib-plantuml		Documentation
sphinx-rtd-theme		Documentation
Git		Firmware, Documentation
Graphviz dot	>v2.38.0	Documentation
docutils	>v2.38.0	Documentation

4. Setup Toolchain¶

To compile RMM code for an AArch64 target, at least one of the supported AArch64 toolchains have to be available in the build environment.

Currently, the following compilers are supported:

GCC (aarch64-none-elf-) >= 10.2-2020.11 (from the Arm Developer website)
Clang+LLVM >= 14.0.0 (from the LLVM Releases website)

The respective compiler binary must be found in the shell’s search path. Be sure to add the bin/ directory if you have downloaded a binary version. The toolchain to use can be set using RMM_TOOLCHAIN parameter and can be set to either llvm or gnu. The default toolchain is gnu.

For non-native AArch64 target build, the CROSS_COMPILE environment variable must contain the right target triplet corresponding to the AArch64 GCC compiler. Below is an example when RMM is to be built for AArch64 target on a non-native host machine and using GCC as the toolchain.

export CROSS_COMPILE=aarch64-none-elf-
export PATH=<path-to-aarch64-gcc>/bin:$PATH

Please note that AArch64 GCC must be included in the shell’s search path even when using Clang as the compiler as LLVM does not include some C standard headers like stdlib.h and needs to be picked up from the include folder of the AArch64 GCC. Below is an example when RMM is to be built for AArch64 target on a non-native host machine and using LLVM as the toolchain.

export CROSS_COMPILE=aarch64-none-elf-
export PATH=<path-to-aarch64-gcc>/bin:<path-to-clang+llvm>/bin:$PATH

The CROSS_COMPILE variable is ignored for fake_host build and the native host toolchain is used for the build.

5. Package Installation (Ubuntu-20.04 x64)¶

If you are using the recommended Ubuntu distribution then we can install the required packages with the following commands:

Install dependencies:

sudo apt-get install -y git build-essential python3 python3-pip make ninja-build
sudo snap install cmake

Verify cmake version:

cmake --version

Note

Please download cmake 3.19 or later version from https://cmake.org/download/.

Add CMake path into environment:

export PATH=<CMake path>/bin:$PATH

6. Install python dependencies¶

Note

The installation of Python dependencies is an optional step. This is required only if building documentation.

RMM’s docs/requirements.txt file declares additional Python dependencies. Install them with pip3:

pip3 install --upgrade pip
cd <rmm source folder>
pip3 install -r docs/requirements.txt

7. Getting the RMM Source¶

Source code for RMM is maintained in a Git repository hosted on TrustedFirmware.org. To clone this repository from the server, run the following in your shell:

git clone --recursive https://git.trustedfirmware.org/TF-RMM/tf-rmm.git

7.1. Additional steps for Contributors¶

If you are planning on contributing back to RMM, your commits need to include a Change-Id footer as explained in Mandated Trailers. This footer is generated by a Git hook that needs to be installed inside your cloned RMM source folder.

The TF-RMM Gerrit page under trustedfirmware.org contains a Clone with commit-msg hook subsection under its Download header where you can copy the command to clone the repo with the required git hooks. Please use the SSH option to clone the repository on your local machine.

If needed, you can also manually install the hooks separately on an existing repo:

curl -Lo $(git rev-parse --git-dir)/hooks/commit-msg https://review.trustedfirmware.org/tools/hooks/commit-msg
chmod +x $(git rev-parse --git-dir)/hooks/commit-msg

You can read more about Git hooks in the githooks page of the Git hooks documentation.

8. Install Cppcheck and dependencies¶

Note

The installation of Cppcheck is an optional step. This is required only if using the Cppcheck static analysis.

Follow the public documentation to install Cppcheck either from the official website https://cppcheck.sourceforge.io/#download or from the official github https://github.com/danmar/cppcheck/

If you own a valid copy of a MISRA rules file:

sudo mkdir /usr/local/share/Cppcheck/misra
sudo cp -a <path to the misra rules file>/<file name> /usr/local/share/Cppcheck/misra/misra.rules

9. Performing an Initial Build¶

The RMM sources can be compiled using multiple CMake options.

For detailed instructions on build configurations and examples see RMM Build Examples.

A typical build command for the FVP platform using GCC toolchain is shown below:

cmake -DRMM_CONFIG=fvp_defcfg -S ${RMM_SOURCE_DIR} -B ${RMM_BUILD_DIR}
cmake --build ${RMM_BUILD_DIR}

10. Running the RMM¶

The RMM is part of the CCA software stack and relies on EL3 Firmware to load the binary at boot time appropriately. It needs both EL3 Firmware and Non-Secure Host to be present at runtime for its functionality. The EL3 Firmware must comply to RMM-EL3 Communication Specification and is typically the TF-A. The Non-Secure Host can be an RME aware hypervisor or an appropriate Test utility running in Non-Secure world which can interact with RMM via Realm Management Interface (RMI).

The TF-A project includes build and run instructions for an RME enabled system on the FVP platform as part of TF-A RME documentation. The rmm.img binary is provided to the TF-A bootloader to be packaged in FIP using RMM build option in TF-A.

If RMM is built for the fake_host architecture (see RMM Fake Host Build), then the generated rmm.elf binary can run natively on the Host machine. It does this by emulating parts of the system as described in RMM Fake host architecture design.