This is clearer and less fragile than trying to make relative calls
work. In particular, the old approach failed if _start was not
== HVMLOADER_PHYSICAL_ADDRESS. This was the case for some modern
toolchains which reorder functions.
Signed-off-by: Keir Fraser <keir@xen.org>
it to interrogate Xen version information. Also add support
for HVM hypercall execution on 64-bit host.
Signed-off-by: Steven Smith <ssmith@xensource.com>
Signed-off-by: Keir Fraser <keir@xensource.com>