LLVM Embedded Toolchain for Arm

The LLVM Embedded Toolchain for Arm allows Cortex-M developers to build projects with the clang compiler.

Pre-built binaries are available for Windows (x86_64), macOS (x86_64 and Apple Silicon), and Linux (x86_64 and AArch64) hosts.

How do I install the LLVM Embedded Toolchain for Arm on Windows?

Copy and paste the URL below into your browser to download the latest release from GitHub:

    

        
        
https://github.com/ARM-software/LLVM-embedded-toolchain-for-Arm/releases/download/release-18.1.3/LLVM-ET-Arm-18.1.3-Windows-x86_64.zip

    

Unzip the download to a location of your choice on your host machine.

Open Windows Control Panel and add the LLVM bin directory to the Path.

Open a Command Prompt and test your installation .

How do I install the LLVM Embedded Toolchain for Arm on macOS?

Copy and paste the URL below into your browser to download the latest release from GitHub:

    

        
        
https://github.com/ARM-software/LLVM-embedded-toolchain-for-Arm/releases/download/release-18.1.3/LLVM-ET-Arm-18.1.3-Darwin-universal.dmg

    

Install the toolchain by clicking on the dmg file and following the instructions.

Add the LLVM bin directory to your PATH:

    

        
        
export PATH=/Applications/LLVM-ET-Arm-18.1.3-Darwin-universal/bin:$PATH

    

The toolchain binaries may be quarantined. Navigate to the bin directory and use the xattr command to remove the quarantine:

    

        
        
cd /Applications/LLVM-ET-Arm-18.1.3-Darwin-universal/bin
find . -type f -perm +0111 | xargs xattr -d com.apple.quarantine

    

You can now test your installation .

How do I install the LLVM Embedded Toolchain for Arm on Linux?

The information below assumes Ubuntu Linux on an AArch64 host. Modify the filenames and paths as needed for other hosts.

Download the latest release using wget:

    

        
        
wget https://github.com/ARM-software/LLVM-embedded-toolchain-for-Arm/releases/download/release-18.1.3/LLVM-ET-Arm-18.1.3-Linux-AArch64.tar.xz

    

Open a terminal application and use tar to extract the file:

    

        
        
tar xfJ LLVM-ET-Arm-18.1.3-Linux-AArch64.tar.xz -C $HOME

    

Add the LLVM bin directory to your PATH:

    

        
        
export PATH=$HOME/LLVM-ET-Arm-18.1.3-Linux-AArch64/bin:$PATH

    

How do I test the LLVM Embedded Toolchain installation?

You can now test your installation.

How do I verify the clang installation?

Use the --version option to verify the correct compiler is being invoked:

    

        
        
clang --version

    

You should observe output similar to:

    

        
        clang version 18.1.3
Target: aarch64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/ubuntu/LLVM-ET-Arm-18.1.3-Linux-AArch64/bin

        
    

How do I build a simple application with clang?

Use a text editor to create an example source file with the name hello.c and the code below:

    

        
        
#include <stdio.h>

int main()
{
  printf("hello");
  return 0;
}

    

A number of compiler options are needed. See Using the toolchain for full details.

To build for Armv6-M:

    

        
        
clang --target=armv6m-none-eabi -fno-exceptions -fno-rtti -lcrt0-semihost -lsemihost -T picolibc.ld -o hello_v6m hello.c

    

To build for Armv7-M:

    

        
        
clang --target=armv7m-none-eabi -fno-exceptions -fno-rtti -lcrt0-semihost -lsemihost -T picolibc.ld -o hello_v7m hello.c

    

How do I run the example applications?

The applications can be run on Fixed Virtual Platforms (FVP) .

To run the Armv6-M example on Cortex-M0 FVP:

    

        
        
FVP_MPS2_Cortex-M0 -a hello_v6m

    

To run the Armv7-M example on Cortex-M3 FVP:

    

        
        
FVP_MPS2_Cortex-M3 -a hello_v7m

    

You will see the hello message on the console (as well as other diagnostic output from the FVP):

    

        
        telnetterminal1: Listening for serial connection on port 5000
telnetterminal2: Listening for serial connection on port 5002
telnetterminal0: Listening for serial connection on port 5001
hello
Info: /OSCI/SystemC: Simulation stopped by user.