bitbake.conf, local.conf.sample: Disable ccache by default

This moves the current CCACHE over to local.conf.sample and documents
when it's useful to enable.

Signed-off-by: Tom Rini <tom_rini@mentor.com>

diff --git a/conf/bitbake.conf b/conf/bitbake.conf
index 0119294..69d00e2 100644 (file)
--- a/conf/bitbake.conf
+++ b/conf/bitbake.conf
@@ -420,7 +420,7 @@ export PATH
 # Build utility info.
 ##################################################################
 
-CCACHE = "${@bb.which(bb.data.getVar('PATH', d, 1), 'ccache') and 'ccache '}"
+CCACHE ?= ""
 TOOLCHAIN_OPTIONS = ""
 TOOLCHAIN_PATH ?= "${CROSS_DIR}"
 TOOLCHAIN_SYSPATH ?= "${TOOLCHAIN_PATH}/${TARGET_SYS}"

diff --git a/conf/local.conf.sample b/conf/local.conf.sample
index 6f2fea6..60c10e4 100644 (file)
--- a/conf/local.conf.sample
+++ b/conf/local.conf.sample
@@ -123,6 +123,11 @@ IMAGE_FSTYPES = "jffs2 tar"
 # (Note that this rootfs is NOT usuable as NFS export.)
 # IMAGE_KEEPROOTFS = "1"
 
+# Uncomment this to enable the use of ccache when building.  Due to
+# the nature of our builds this is only helpful in cases when one
+# is rebuilding a recipe or set of recipes, repeatedly.
+# CCACHE = "${@bb.which(bb.data.getVar('PATH', d, 1), 'ccache') and 'ccache '}"
+
 # Uncomment this to disable the parse cache (not recommended).
 # CACHE = ""