Hi Davy,
Export the needed variables to the environment and add the path to the toolchain to the $PATH variable:
export CROSS_COMPILE=arm-linux-gnueabihf-
export ARCH=arm
export PATH=$PATH:/usr/local/ti-sdk-am335x-evm/linux-devkit/sysroots/i686-arago-linux/usr/bin
Then verify everything is exported correctly:
which arm-linux-gnueabihf-gcc
This should point to the correct file in the toolchain folder.
Then build your U-Boot:
make am335x_evm
Best regards,
Miroslav
