Enable multiple custom toolchains

Change-Id: Ifcde6cbfe2782a7456f2b55386748227f593122a
Prepare Mackay ROM script with info

Change-Id: If0d39ab673397462dc43d6bec48f6142d802fe2b
Move the final messages to a more logical place

Change-Id: If9215f4d5c1938c6dfa68651a4ad1ad2bbb36b19