# Build Variables

Setting Host and Target

During the building of the cross-compile tools you will need to set a few variables that will be dependent on your particular needs. The first variable will be the triplet of the host machine, which will be put into the `CLFS_HOST` variable. To account for the possibility that the host and target are the same arch, as cross-compiling won't work when host and target are the same, part of the triplet needs to be changed slightly to add "cross". Set `CLFS_HOST` using the following command:

    export CLFS_HOST=$(echo ${MACHTYPE} | sed -e 's/-[^-]*/-cross/')

Now you will need to set the triplet for the target architecture. Set the target variable using the following command:

    export CLFS_TARGET="[target triplet]"

Replace [target triplet] with the appropriate machine triplet using the table at the bottom of the page.

Copy settings to the Environment

Now add these to `~/.bashrc`, just in case you have to exit and restart building later:

    cat >> ~/.bashrc << EOF
    export CLFS_HOST="${CLFS_HOST}"
    export CLFS_TARGET="${CLFS_TARGET}"
    EOF

## Processor Type and Target Triplets

Processor | Target Triplet
386 Compatibles | Not Supported By Glibc
486 Compatibles | i486-pc-linux-gnu
Pentium, K6, 586 Compatibles | i586-pc-linux-gnu
Pentium II, Pentium III, Pentium 4 | i686-pc-linux-gnu
Athlon, Duron | i686-pc-linux-gnu