NAME
    legato-qemu - launch qemu

DESCRIPTION
    Prepare an launch qemu to host an instance of Legato.
    Also fetch qemu images and check for updates.

ENVIRONMENT
    This script is parametrized through environment variables.
        OPT_TARGET: Platform to emulate
        OPT_PERSIST: Make changes to the image persistant or not
        OPT_KMESG: Kernel messages to console
        OPT_GDB: Launch GDB server to qemu
        OPT_SERIAL: Bearer for serial port
                    - (blank, default) = Serial to console
                    - telnet = Serial to telnet
        OPT_NET: Networking interface
                 - user (default) = simulated internal qemu networking
                 - tap = Uses a tap interface (requires priviledges)