As discussed in the BR developer days, we want to be more strict about API
changes in buildroot. I.e., we want to make it less likely that a user's
customizations break down after upgrading buildroot.
A first step is to make sure that the user is warned about API changes.
This patch introduces Makefile.legacy and Config.in.legacy, which will
issue clear error messages for such situations.
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>