This simple stub allows you to extend your kernel with an easy message to identify its boot mode. Should work with any Xen-compatible kernel; but isn't needed if your kernel is new enough.
- ARM32: 3.7+ will print this out for you, so this isn't needed!
- ARM64: 4.3+ will print this out for you, so this isn't needed!
- Earlier kernels: try this!
As the relevant mode information isn't exported, this stub has to be linked into your kernel. Luckily, that's fairly easy. Copy this source file to the "drivers/misc" folder of your kernel source tree, and then add it to the relevant Makefile.
# Copy the file in...
$ cp hypcheck.o <kernel-path>/drivers/misc/
# ... add it to our build...
$ echo "obj-y += hypcheck.o" >> <kernel-path>/drivers/misc/Makefile
# ... and (re)build our kernel.
$ cd <kernel-path>
$ make