Comment 8 for bug 1507738

Reviewed: https://review.openstack.org/254759
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=35c7f81fa80c44e22d660d0d57f2419430408f43
Submitter: Jenkins
Branch: stable/liberty

commit 35c7f81fa80c44e22d660d0d57f2419430408f43
Author: Lucas Alvares Gomes <email address hidden>
Date: Fri Oct 9 11:26:13 2015 +0100

    iPXE: Fix assumption that ${mac} is the MAC of the NIC it's booting

    The ${mac} variable not necessarily points to the MAC address of the NIC
    we are booting from. This patch updates the boot.ipxe script to make it
    more robust by interating over all NICs found in the machine and boot
    from the first one capable of booting (the one that contains a
    configuration file in the server). If no NICs are capable of booting the
    script will fail just like before telling the user that the network boot
    failed because we couldn't find any configuration for the present NICs.

    In case the inc command is not found, the boot.ipxe will fall back to
    the old behavior.

    This backport is the combination of 2 commits (squashed):

    (cherry picked from commit 1c28eb79a5d1b25fb685e2f48449c51e905766b5)
    (cherry picked from commit f968e1a22d3ed928278a04f0da9124678474ff0a)

    We need to squash both patches because they must merge at the same time
    to avoid breakages.

    Closes-Bug: #1507738
    Closes-Bug: #1504482
    Change-Id: I5b8f0740fa42f611e84b66dc7f6578cffe02760a