41 lines
1.8 KiB
ReStructuredText
41 lines
1.8 KiB
ReStructuredText
.. SPDX-License-Identifier: CC-BY-SA-2.0-UK
|
|
|
|
Optionally Using an External Toolchain
|
|
**************************************
|
|
|
|
You might want to use an external toolchain as part of your development.
|
|
If this is the case, the fundamental steps you need to accomplish are as
|
|
follows:
|
|
|
|
- Understand where the installed toolchain resides. For cases where you
|
|
need to build the external toolchain, you would need to take separate
|
|
steps to build and install the toolchain.
|
|
|
|
- Make sure you add the layer that contains the toolchain to your
|
|
``bblayers.conf`` file through the
|
|
:term:`BBLAYERS` variable.
|
|
|
|
- Set the :term:`EXTERNAL_TOOLCHAIN` variable in your ``local.conf`` file
|
|
to the location in which you installed the toolchain.
|
|
|
|
The toolchain configuration is very flexible and customizable. It
|
|
is primarily controlled with the :term:`TCMODE` variable. This variable
|
|
controls which ``tcmode-*.inc`` file to include from the
|
|
``meta/conf/distro/include`` directory within the :term:`Source Directory`.
|
|
|
|
The default value of :term:`TCMODE` is "default", which tells the
|
|
OpenEmbedded build system to use its internally built toolchain (i.e.
|
|
``tcmode-default.inc``). However, other patterns are accepted. In
|
|
particular, "external-\*" refers to external toolchains. One example is
|
|
the Mentor Graphics Sourcery G++ Toolchain. Support for this toolchain resides
|
|
in the separate ``meta-sourcery`` layer at
|
|
https://github.com/MentorEmbedded/meta-sourcery/.
|
|
See its ``README`` file for details about how to use this layer.
|
|
|
|
Another example of external toolchain layer is
|
|
:yocto_git:`meta-arm-toolchain </meta-arm/tree/meta-arm-toolchain/>`
|
|
supporting GNU toolchains released by ARM.
|
|
|
|
You can find further information by reading about the :term:`TCMODE` variable
|
|
in the Yocto Project Reference Manual's variable glossary.
|