building/toolchains.rst

.. _toolchains:

##########
Toolchains
##########
OP-TEE uses both 32bit as well as 64bit toolchains and it is even possible to
mix them in some configurations. In theory you should be able to compile OP-TEE
with the Arm toolchains that are coming with your Linux distribution. But
instead of using those directly, we instead download the toolchains directly
from Arm.

Download/install
****************
We propose two ways to download the toolchains, both will put the toolchains
under the same path(s).

1. Direct download
==================
Go the `Arm GCC download page`_ and download the "`AArch32 target with soft
float (arm-linux-gnueabi)`" for 32bit builds and the "`AArch64 GNU/Linux target
(aarch64-linux-gnu)`" for 64bit builds. When the downloads have finished, you
will untar them to a location that you later on will export to your ``$PATH``.
Here is an example

.. code-block:: bash

    $ mkdir -p $HOME/toolchains
    $ cd $HOME/toolchains

    # Download 32bit toolchain
    $ wget https://developer.arm.com/-/media/Files/downloads/gnu-a/8.2-2019.01/gcc-arm-8.2-2019.01-x86_64-arm-linux-gnueabi.tar.xz
    $ mkdir aarch32
    $ tar xf gcc-arm-8.2-2019.01-x86_64-arm-linux-gnueabi.tar.xz -C aarch32 --strip-components=1

    # Download 64bit toolchain
    $ wget https://developer.arm.com/-/media/Files/downloads/gnu-a/8.2-2019.01/gcc-arm-8.2-2019.01-x86_64-aarch64-linux-gnu.tar.xz
    $ mkdir aarch64
    $ tar xf gcc-arm-8.2-2019.01-x86_64-aarch64-linux-gnu.tar.xz -C aarch64 --strip-components=1

2. Using build.git
==================
As an alternative, you can let :ref:`build`.git download them for you, but this
of course involves getting a git that you might not otherwise use.

.. code-block:: bash

    $ cd $HOME
    $ git clone https://github.com/OP-TEE/build.git
    $ cd build
    $ make -f toolchain.mk -j2


Export PATH
***********
If you have downloaded the toolchains as described above, you should have them
at ``$HOME/toolchains/{aarch32/aarch64}``, so now we just need to export the
paths and then you are ready to starting compiling OP-TEE components.

.. code-block:: bash

    $ export PATH=$PATH:$HOME/toolchains/aarch32/bin:$HOME/toolchains/aarch64/bin

.. _Arm GCC download page: https://developer.arm.com/open-source/gnu-toolchain/gnu-a/downloads