Setup an external toolchain with Yocto

You can use the sourcery g++ toolchain, but it requires custom tuning arguments to control selection of the multilib in the external toolchain sysroots, so you should switch to a separate layer and override the tuning files in question.

For example.

If you want to see an example of external toolchain stuff that works, see the meta-sourcery layer.

Watch this presentation about how to setup an external toolchain with oe-core.

• Example with Linaro toolchain

#
# Setting the following variables will enable the use of the Linaro toolchain. If not set
#     you will build using gcc built by Yocto. EXTERNAL_TOOLCHAIN must be set to the path
#     where the linaro toolchain exists and should have subdirectories named lib, bin, etc
#

TCLIBC = "external-linaro-toolchain"
TCMODE = "external-linaro"
EXTERNAL_TOOLCHAIN = "/home/rpjday/altera-linux/linaro/gcc-linaro-arm-linux-gnueabihf-4.7-2012.11-20121123_linux"