### 4.1 Global configuration file ¶

The global configuration file is where all the target specific configuration variables for a site are set. For example, a centralized testing lab where multiple developers have to share an embedded development board. There are settings for both remote hosts and remote targets. Below is an example of a global configuration file for a Canadian cross environment. A Canadian cross is a toolchain that is built on, runs on, and targets three different system triplets (for example, building a Solaris-hosted MIPS R4000 toolchain on a GNU/Linux system). This example is based on a configuration once used at Cygnus.

Example global configuration file

    # Make sure we look in the right place for the board description files.
    lappend boards_dir "/nfs/cygint/s1/cygnus/dejagnu/boards"

    verbose "Global config file: target_triplet is $target_triplet" 2
    global target_list

    switch -glob -- $target_triplet {
        "native" {
            set target_list "unix"
        }
        "sparc64-*elf" {
            set target_list "sparc64-sim"
        }
        "mips-*elf" {
            set target_list "mips-sim wilma barney"
        }
        "mips-lsi-elf" {
            set target_list "mips-lsi-sim{,soft-float,el}"
        }
    }

In this case, we have support for several cross compilers, that all run on this host. To run DejaGnu tests on tools hosted on operating systems that do not run Expect, DejaGnu can be run on the build machine and connect to the remote host to run all the tests. As you can see, all one does is set the variable `target_list` to the list of targets and options to test.

In this example, simple cases like sparc64-elf only require setting the name of the single board configuration file. The mips-elf target is more complicated and sets the list to three target boards. mips-sim is a symbolic name for a simulator “board” and wilma and barney are symbolic names for physical boards. Symbolic names are covered in the Adding a new board section. The more complicated example is the entry for mips-lsi-elf. This one runs the tests with multiple iterations using all possible combinations of the `--soft-float` and the `--el` (little endian) options. The braced string includes an initial comma so that the set of combinations includes no options at all. Needless to say, this last target example is mostly specific to compiler testing.