This commit adds support of Xen Enlighten page and initial support for
Xen event channels. It is needed for future Xen PV drivers
implementation.
Now enlighten page is mapped to the prepared memory area on
PRE_KERNEL_1 stage. In case of success event channel logic gets
inited and can be used ASAP after Zephyr start. Current implementation
allows to use only pre-defined event channels (PV console/XenBus) and
works only in single CPU mode (without VCPUOP_register_vcpu_info).
Event channel allocation will be implemented in future versions.
Signed-off-by: Dmytro Firsov <dmytro_firsov@epam.com>
01a9b117fe