lib/oe/image.py: check the rootfs size against IMAGE_ROOTFS_MAXSIZE

* Check the rootfs size against IMAGE_ROOTFS_MAXSIZE (if set)
* Add comments for IMAGE_ROOTFS_SIZE to not confuse with IMAGE_ROOTFS_MAXSIZE

[YOCTO #2610]

(From OE-Core rev: 6acd4fc8d5e642b5c6c75fcc40dd8f37caf7ddcf)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
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 311e9a04c4..f4870d52a9 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -688,6 +688,10 @@ IMAGE_FSTYPES ?= "tar.gz"
 INITRAMFS_FSTYPES ?= "cpio.gz"
 DEFAULT_TASK_PROVIDER ?= "packagegroup-base"
 MACHINE_TASK_PROVIDER ?= "${DEFAULT_TASK_PROVIDER}"
+
+# The size in Kbytes for the generated image if it is larger than
+# the required size (du -ks IMAGE_ROOTFS * IMAGE_OVERHEAD_FACTOR),
+# and no effect if less than it.
 IMAGE_ROOTFS_SIZE ?= "65536"
 
 # Forcefully set CACHE now so future changes to things like