[PATCH] Add new IMAGE_CLASSES variable for classes for image generation

[Matthew McClintock <msm@freescale.com>]

Allows us to import classes only for images and not to the global
namespace

Signed-off-by: Matthew McClintock <msm@freescale.com>
---
This is a resend

 meta-yocto/conf/local.conf.sample |    6 ++++++
 meta/classes/image.bbclass        |    3 ++-
 2 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/meta-yocto/conf/local.conf.sample b/meta-yocto/conf/local.conf.sample
index da3f8df..5e59ad4 100644
--- a/meta-yocto/conf/local.conf.sample
+++ b/meta-yocto/conf/local.conf.sample
@@ -163,6 +163,12 @@ EXTRA_IMAGE_FEATURES = "debug-tweaks"
 # NOTE: mklibs also needs to be explicitly enabled for a given image, see local.conf.extended
 USER_CLASSES ?= "image-mklibs image-prelink"
 
+# Additional image generation features
+#
+# The following is a list of classes to import to use in the generation of images
+# currently an example class is image_types_uboot
+# IMAGE_CLASSES ?= "image_types_uboot"
+
 #
 # Runtime testing of images
 #
diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index 05f4331..e932879 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -111,7 +111,8 @@ def get_devtable_list(d):
         str += " %s" % bb.which(bb.data.getVar('BBPATH', d, 1), devtable)
     return str
 
-inherit image_types
+IMAGE_CLASSES = "image_types"
+inherit ${IMAGE_CLASSES}
 
 IMAGE_POSTPROCESS_COMMAND ?= ""
 MACHINE_POSTPROCESS_COMMAND ?= ""
-- 
1.7.6.1