Hi Henning,

One use-case on our side is the generation of SWUpdate image. Our helper 
class uses do_ext4_image to generate the file-system image we later embed 
into the .swu file

Hope that helps
Cedric

On Tuesday, February 19, 2019 at 10:25:58 AM UTC+1, Henning Schild wrote:
>
> Hi, 
>
> did you do some research on ext4-usage, we might be able to just drop 
> it and use wic instead. The qemus will have to switch from i.e. 
> root=/dev/sda to /dev/sda1 ... sounds easy enough. As far as i can tell 
> they are the only users in Isar. And outside a raw ext4 partition does 
> not seem to be too useful either, we could always keep it as 
> "deprecated" if we are afraid of that move. 
>
> Henning 
>
> On Mon, 18 Feb 2019 14:04:29 +0100 
> "[ext] claudius....@siemens.com <javascript:>" <claudius....@siemens.com 
> <javascript:>> 
> wrote: 
>
> > From: Claudius Heine <c...@denx.de <javascript:>> 
> > 
> > EXT4_IMAGE_FILE does no longer contain the full path to the ext4 image 
> > in the deploy directory. 
> > 
> > Signed-off-by: Claudius Heine <c...@denx.de <javascript:>> 
> > --- 
> >  meta-isar/classes/rpi-sdimg.bbclass |  2 +- 
> >  meta/classes/ext4-img.bbclass       | 31 
> > +++++++++++------------------ 2 files changed, 13 insertions(+), 20 
> > deletions(-) 
> > 
> > diff --git a/meta-isar/classes/rpi-sdimg.bbclass 
> > b/meta-isar/classes/rpi-sdimg.bbclass index 91b09cd..4e5d170 100644 
> > --- a/meta-isar/classes/rpi-sdimg.bbclass 
> > +++ b/meta-isar/classes/rpi-sdimg.bbclass 
> > @@ -15,7 +15,7 @@ BOOT_SPACE ?= "40960" 
> >  IMAGE_ROOTFS_ALIGNMENT = "4096" 
> >   
> >  SDIMG = "${DEPLOY_DIR_IMAGE}/${PN}.rpi-sdimg" 
> > -SDIMG_ROOTFS = "${EXT4_IMAGE_FILE}" 
> > +SDIMG_ROOTFS = "${DEPLOY_DIR_IMAGE}/${EXT4_IMAGE_FILE}" 
> >   
> >  do_rpi_sdimg () { 
> >      # Align partitions 
> > diff --git a/meta/classes/ext4-img.bbclass 
> > b/meta/classes/ext4-img.bbclass index 29e5f77..2620de9 100644 
> > --- a/meta/classes/ext4-img.bbclass 
> > +++ b/meta/classes/ext4-img.bbclass 
> > @@ -1,30 +1,23 @@ 
> >  # This software is a part of ISAR. 
> >  # Copyright (C) 2015-2017 ilbers GmbH 
> >   
> > -EXT4_IMAGE_FILE = "${DEPLOY_DIR_IMAGE}/${IMAGE_FULLNAME}.ext4.img" 
> > +EXT4_IMAGE_FILE = "${IMAGE_FULLNAME}.ext4.img" 
> > + 
> > +IMAGER_INSTALL += "e2fsprogs" 
> >   
> >  do_ext4_image[stamp-extra-info] = "${DISTRO}-${MACHINE}" 
> >   
> >  # Generate ext4 filesystem image 
> >  do_ext4_image() { 
> > -    rm -f ${EXT4_IMAGE_FILE} 
> > - 
> > -    dd if=/dev/zero of=${EXT4_IMAGE_FILE} bs=1k count=${ROOTFS_SIZE} 
> > - 
> > -    sudo mkfs.ext4 -F ${EXT4_IMAGE_FILE} 
> > - 
> > -    mkdir -p ${WORKDIR}/mnt 
> > -    sudo mount -o loop ${EXT4_IMAGE_FILE} ${WORKDIR}/mnt 
> > -    _do_ext4_image_cleanup() { 
> > -        ret=$? 
> > -        sudo umount ${WORKDIR}/mnt 2>/dev/null || true 
> > -        sudo rmdir ${WORKDIR}/mnt 2>/dev/null || true 
> > -        (exit $ret) || bb_exit_handler 
> > -    } 
> > -    trap '_do_ext4_image_cleanup' EXIT 
> > -    sudo cp -r ${IMAGE_ROOTFS}/* ${WORKDIR}/mnt 
> > -    _do_ext4_image_cleanup 
> > +    rm -f '${DEPLOY_DIR_IMAGE}/${EXT4_IMAGE_FILE}' 
> > + 
> > +    truncate -s ${ROOTFS_SIZE}K 
> > '${DEPLOY_DIR_IMAGE}/${EXT4_IMAGE_FILE}' + 
> > +    image_do_mounts 
> > + 
> > +    sudo chroot ${BUILDCHROOT_DIR} /sbin/mke2fs ${MKE2FS_ARGS} \ 
> > +                -F -d '${PP_ROOTFS}' 
> > '${PP_DEPLOY}/${EXT4_IMAGE_FILE}' } 
> >   
> > -addtask ext4_image before do_build after do_copy_boot_files 
> > +addtask ext4_image before do_build after do_copy_boot_files 
> > do_install_imager_deps do_ext4_image[prefuncs] = 'set_image_size' 
>
>