13.6 Specifying the System Type

There may be some features configure cannot figure out automatically, but needs to determine by the type of host the package will run on. Usually configure can figure that out, but if it prints a message saying it cannot guess the host type, give it the `--build=type' option. type can either be a short name for the system type, such as `sun4', or a canonical name which has the form:

cpu-company-system

where system can have one of these forms:

os kernel-os

See the file `config.sub' for the possible values of each field. If `config.sub' isn't included in this package, then this package doesn't need to know the host type.

If you are building compiler tools for cross-compiling, you should use the `--target=type' option to select the type of system they will produce code for.

If you want to use a cross compiler, that generates code for a platform different from the build platform, you should specify the host platform (i.e., that on which the generated programs will eventually be run) with `--host=type'. In this case, you should also specify the build platform with `--build=type', because, in this case, it may not be possible to guess the build platform (it sometimes involves compiling and running simple test programs, and this can't be done if the compiler is a cross compiler).