local.conf.sample: use ?= to assign BB_ENV_EXTRAWHITE variables

Use ?= so that the BB_ENV_EXTRAWHITE variables can be overridden from
the environment.

[YOCTO #4367]

Signed-off-by: Jesse Zhang <sen.zhang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

3 files changed, 6 insertions, 6 deletions

diff --git a/meta-yocto/conf/local.conf.sample b/meta-yocto/conf/local.conf.sample
index 1abe2247b9..2d89282198 100644
--- a/meta-yocto/conf/local.conf.sample
+++ b/meta-yocto/conf/local.conf.sample
@@ -17,12 +17,12 @@
 # These two options control how much parallelism BitBake should use. The first 
 # option determines how many tasks bitbake should run in parallel:
 #
-#BB_NUMBER_THREADS = "4"
+#BB_NUMBER_THREADS ?= "4"
 # 
 # The second option controls how many processes make should run in parallel when
 # running compile tasks:
 #
-#PARALLEL_MAKE = "-j 4"
+#PARALLEL_MAKE ?= "-j 4"
 #
 # For a quad-core machine, BB_NUMBER_THREADS = "4", PARALLEL_MAKE = "-j 4" would
 # be appropriate for example.
diff --git a/meta-yocto/conf/local.conf.sample.extended b/meta-yocto/conf/local.conf.sample.extended
index 3dc73fbec6..07e5cf553a 100644
--- a/meta-yocto/conf/local.conf.sample.extended
+++ b/meta-yocto/conf/local.conf.sample.extended
@@ -82,7 +82,7 @@
 # Use "external-MODE" to use the precompiled external toolchains where MODE
 # is the type of external toolchain to use e.g. eabi. You need to ensure 
 # the toolchain you want to use is included in an appropriate layer
-# TCMODE = "external-eabi"
+# TCMODE ?= "external-eabi"
 
 # mklibs library size optimization is more useful to smaller images,
 # and less useful for bigger images. Also mklibs library optimization
diff --git a/meta-yocto/conf/site.conf.sample b/meta-yocto/conf/site.conf.sample
index b2d01d0c59..c551e8fb0c 100644
--- a/meta-yocto/conf/site.conf.sample
+++ b/meta-yocto/conf/site.conf.sample
@@ -19,10 +19,10 @@ SCONF_VERSION = "1"
 # To use git with a proxy, you must use an external git proxy command, such as
 # the one provided by scripts/oe-git-proxy.sh. To use this script, copy it to
 # your PATH and uncomment the following:
-#GIT_PROXY_COMMAND="oe-git-proxy"
-#ALL_PROXY="socks://socks.example.com:1080"
+#GIT_PROXY_COMMAND ?= "oe-git-proxy"
+#ALL_PROXY ?= "socks://socks.example.com:1080"
 #or
-#ALL_PROXY="https://proxy.example.com:8080"
+#ALL_PROXY ?= "https://proxy.example.com:8080"
 # If you wish to use certain hosts without the proxy, specify them in NO_PROXY.
 # See the script for details on syntax.