4.3. Apple macOS — RTEMS User Manual 5.4-rc2 (21st August 2026) documentation

# 4.3. Apple macOS

Apple’s macOS is fully supported. You need to download and install a recent version of the Apple developer application Xcode. Xocde is available in the App Store. Make sure you install the Command Line Tools add on available for download within Xcode and once installed open a Terminal shell and enter the command `cc` and accept the license agreement.

The normal prefix when working on macOS as a user is under your home directory. Prefixes of `$HOME/development/rtems` or `$HOME/rtems` are suitable.

Choose an Installation Prefix details using Prefixes to manage the installation.

## 4.3.1. Catalina

In the macOS Catalina 10.15 Release Notes Apple deprecated several scripting language runtimes such as Python 2.7. See also Xcode 11 Release Notes. Due to the deprecated Python 2.7 support, we recommend to install and use the latest Python 3 release from python.org.

## 4.3.2. Sierra

The RSB works on Sierra with the latest Xcode.

## 4.3.3. Mavericks

The RSB works on Mavericks and the GNU tools can be built for RTEMS using the Mavericks clang LLVM tool chain. You will need to build and install a couple of packages to make the RSB pass the `sb-check`. These are CVS and XZ. You can get these tools from a packaging tool for macOS such as MacPorts or HomeBrew.

I do not use third-party packaging on macOS and prefer to build the packages from source using a prefix of `/usr/local`. There are good third-party packages around however they sometimes bring in extra dependence and that complicates my build environment and I want to know the minimal requirements when building tools. The following are required:

. The XZ package’s home page is http://tukaani.org/xz/ and I use version

  5.0.5. XZ builds and installs cleanly.