To build the bruno toolchain:

TOOLCHAIN_DIR=<path-to-toolchain-slash-bruno>
BUILD_INFO_DIR=$TOOLCHAIN_DIR/Build.Info

mkdir <some_dir_somewhere>
cd <some_dir_somewhere>

git clone git://git.buildroot.net/buildroot
cd buildroot
git checkout 2016.02

for patch_file in `ls $BUILD_INFO_DIR/*.patch`; do patch -p1 -i $patch_file; done

cp $BUILD_INFO_DIR/defconfig .config

make
(this will bring up menuconfig, just exit and save)
make -j12

rm -r $TOOLCHAIN_DIR/usr
cp -r output/host/usr $TOOLCHAIN_DIR/usr

cd $TOOLCHAIN_DIR

# Let buildroot access the toolchain thru /bin instead of /usr/bin.
rm -r bin
mkdir bin
cd bin
cp ../Build.Info/proxy .
for file in $(ls -l ../usr/bin | grep -- "-> toolchain-wrapper" | awk '{print $9}'); do echo $file; ln -s proxy $file; done
for file in $(ls -l ../usr/bin | grep -v toolchain-wrapper | grep -v "\\.br_real" | awk '{print $9}'); do ln -s ../usr/bin/$file $file; done

cd $TOOLCHAIN_DIR

# Copy/link .so files to legacy locations:
ln -s ../usr/lib/libstdc++.so usr/mipsel-buildroot-linux-uclibc/sysroot/lib/libstdc++.so
cp usr/mipsel-buildroot-linux-uclibc/lib/libstdc++.la usr/mipsel-buildroot-linux-uclibc/sysroot/lib/.
ln -s libdl.so.1 usr/mipsel-buildroot-linux-uclibc/sysroot/lib/libdl.so.0
ln -s librt.so.1 usr/mipsel-buildroot-linux-uclibc/sysroot/lib/librt.so.0
ln -s libpthread.so.1 usr/mipsel-buildroot-linux-uclibc/sysroot/lib/libpthread.so.0
ln -s libm.so.1 usr/mipsel-buildroot-linux-uclibc/sysroot/lib/libm.so.0
ln -s libc.so.1 usr/mipsel-buildroot-linux-uclibc/sysroot/lib/libc.so.0

git add .
git commit