Some errors with the Makefiles on Mac OSX

I am having some issues with the Makefiles in the kernel and libc folders. The first issue is the first three lines of the files, I couldn't get your version to work for some reason but this worked for me:

DEFAULT_HOST=$(shell ../default-host.sh)
HOST?=$(DEFAULT_HOST)
HOSTARCH=$(shell ../target-triplet-to-arch.sh $(HOST))

The only other issue I encountered was the --preserve=timestamps not working when copying the headers, I suppose because the default cp doesn't have that option. Everything else is great. I'm on OSX 10.11, if it's relevant.