Re: [PATCH 3/3] Empty image: filesystem allocation

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Fri, 2015-09-11 at 12:26 -0500, Benjamin Esquivel wrote:
> Hi Alejandro,
> 
> On Wed, 2015-08-26 at 16:57 -0500, Alex Franco wrote:
> > Increase sparse image block size when ROOTFS_SIZE is smaller than
> > the minimum needed for ext4 to fit into it.
> > 
> > [YOCTO #7664]
> > 
> > Signed-off-by: Alex Franco <alejandro.franco@linux.intel.com>
> > ---
> >  meta/classes/image_types.bbclass | 10 +++++++++-
> >  1 file changed, 9 insertions(+), 1 deletion(-)
> > 
> > diff --git a/meta/classes/image_types.bbclass
> > b/meta/classes/image_types.bbclass
> > index 35ceb7b..61ce222 100644
> > --- a/meta/classes/image_types.bbclass
> > +++ b/meta/classes/image_types.bbclass
> > @@ -49,8 +49,16 @@ oe_mkext234fs () {
> >  		extra_imagecmd=$@
> >  	fi
> >  
> > +	# If generating an empty image the size of the sparse block
> > should be large
> > +	# enough to allocate an ext4 filesystem using 4096 bytes per
> > inode, this is
> > +	# about 60K, so dd needs a minimum count of 60, with bs=1024
> > (bytes per IO)
> > +	eval local COUNT=\"0\"
> > +	eval local MIN_COUNT=\"60\"
> > +	if [ $ROOTFS_SIZE -lt $MIN_COUNT ]; then
> > +		eval COUNT=\"$MIN_COUNT\"
> > +	fi
> >  	# Create a sparse image block
> > -	dd if=/dev/zero
> > of=${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.$fstype seek=$ROOTFS_SIZE
> > count=0 bs=1k
> > +	dd if=/dev/zero
> > of=${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.$fstype seek=$ROOTFS_SIZE
> > count=$COUNT bs=1024
> Variable references enclosed in {} are less prone to misinterpretation.

They are however more likely to get expanded by bitbake before you'd
expect them to be unfortunately :(

Cheers,

Richard


> >  	mkfs.$fstype -F $extra_imagecmd
> > ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.$fstype -d ${IMAGE_ROOTFS}
> >  }
> >  
> > -- 
> > 2.5.0
> >