• Robbie Cao's avatar
    armv8r64-extras/xen-devicetree: Exclude evtchn if only 1 domain · b1eda310
    Robbie Cao authored
    The event channel is established statically for communication between
    two domains. There is no need to define event channels in device tree
    if only one domain is running on Xen. Also, since the event channel
    must describe the foreign-evtchn phandle connected to in the device
    tree, this is missing in the case of only one domain running on Xen,
    which causes the device tree overlay to fail.
    Based on the above reason, this patch adds a switch to enable the
    description of evtchn in the device tree. Whether it is enabled or not
    is determined by the 'XEN_DOM0LESS_DOMAINS' configuration: if only one
    domain runs on Xen, evtchn will be excluded from the device tree.
    This functionality is achieved by:
    1. Wrap the evtchn node in '#if VAR / #endif'
    2. The value of VAR (0 or 1) is determined by XEN_DOM0LESS_DOMAINS
    3. Use cpp (c preprocessor) to generate dts that meet the conditions
    Issue-Id: SCM-5451
    Signed-off-by: default avatarRobbie Cao <robbie.cao@arm.com>
    Change-Id: I9c96f0b9de502757a1f29c6f022addb842990bee