We have some header files that relate to our specific hardware that we need to get placed in qnx_target/usr/include. 
There's no source files to compile in this case.

I can't find an example of a project directory which just contains headers. They all contain assembly or .c source files
 to compile.

For example, I want to create:

  src/hardware/foo/public/bar/xyzzy.h

...and have xyzzy.h copied to qnx_target/usr/include/bar as part of the hinstall processing.

It's not clear to me which make file "triggers" the hinstall processing.

I started with creating a basic Makefile in the foo directory that just contained:

LIST=foo
include recurse.mk

But it seems like I need a common.mk and a lower directory to include it.

I could just place the files in src/hardware/startup/lib/public, but didn't really want to use that approach.