Use "??=" to set default ROOT_HOME. It can be overwrote by developer
with "?=" in any layer and at same time it also can be overwrote in
local.conf.
(From OE-Core rev:
902d3fa57d4659ee12aac80246dcaca5c45f9d8c)
Signed-off-by: Kang Kai <kai.kang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
USRBINPATH_class-nativesdk = "/usr/bin"
# Root home directory
-ROOT_HOME ?= "/home/root"
+ROOT_HOME ??= "/home/root"
##################################################################
# Architecture-dependent build variables.