[PATCH v6 1/5] build: Env var to enable expert config options

[Jonathan Creekmore <jonathan.creekmore@gmail.com>]

Add an additional environment variable, defaulting to disabled,
that enables the CONFIG_EXPERT configuration option. The purpose
of the CONFIG_EXPERT configuration option is to make non-standard
Kconfig options visible during the configuration process. The
CONFIG_EXPERT option is not, itself, visible during the Kconfig
configuration process, so typical users will never see it nor
any of the non-standard configuration options.

CC: Ian Campbell <ian.campbell@citrix.com>
CC: Ian Jackson <ian.jackson@eu.citrix.com>
CC: Jan Beulich <jbeulich@suse.com>
CC: Keir Fraser <keir@xen.org>
CC: Tim Deegan <tim@xen.org>
Signed-off-by: Jonathan Creekmore <jonathan.creekmore@gmail.com>
Reviewed-by: Doug Goldstein <cardoe@cardoe.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 xen/Kconfig  | 4 ++++
 xen/Makefile | 1 +
 2 files changed, 5 insertions(+)

diff --git a/xen/Kconfig b/xen/Kconfig
index ffe3f45..fa8b27c 100644
--- a/xen/Kconfig
+++ b/xen/Kconfig
@@ -22,3 +22,7 @@ config DEFCONFIG_LIST
 	string
 	option defconfig_list
 	default "$ARCH_DEFCONFIG"
+
+config EXPERT
+	string
+	option env="XEN_CONFIG_EXPERT"
diff --git a/xen/Makefile b/xen/Makefile
index 3699b20..e03e79b 100644
--- a/xen/Makefile
+++ b/xen/Makefile
@@ -11,6 +11,7 @@ export XEN_DOMAIN	?= $(shell ([ -x /bin/dnsdomainname ] && /bin/dnsdomainname) |
 export XEN_BUILD_DATE	?= $(shell LC_ALL=C date)
 export XEN_BUILD_TIME	?= $(shell LC_ALL=C date +%T)
 export XEN_BUILD_HOST	?= $(shell hostname)
+export XEN_CONFIG_EXPERT ?= n
 
 export BASEDIR := $(CURDIR)
 export XEN_ROOT := $(BASEDIR)/..
-- 
2.6.4