image_types: add IMAGE_ROOTFS_EXTRA_SPACE

[YOCTO #886]

This address 2 needs after the IMAGE_ROOTFS_SIZE is cleaned up, by
removing the _ext2/3 overrides it allows for a cleaner override
using IMAGE_ROOTFS_SIZE to create a large rootfs, or by setting the
IMAGE_ROOTFS_EXTRA_SPACE, will allow for extra space allocated in Kilobytes
above the base size (determined by du of the rootfs * IMAGE_OVERHEAD_FACTOR,
default of 1.3).

(From OE-Core rev: 367934ada7c081ba3fc95f02dc14c7d6f97bfccb)

Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 18028f3001..35fd6f864f 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -350,6 +350,10 @@ IMAGE_LINK_NAME = "${IMAGE_BASENAME}-${MACHINE}"
 # This option allows for a precentage overage of the actaul image size rather than a
 # fixed extra space
 IMAGE_OVERHEAD_FACTOR ?= 1.3
+# This option allow for adding addition space in K above and beyond what the 
+# IMAGE_OVERHEAD_FACTOR might add. To set a fixed size then overrideing IMAGE_ROOTFS_SIZE
+# with the max size one wants should do the trick
+IMAGE_ROOTFS_EXTRA_SPACE = "0"
 
 EXTRA_IMAGEDEPENDS = ""