[OE-core] [PATCH] image.bbclass: Always try to run populate-volatile.sh at rootfs time

[Mike Looijmans]

Any comments on this?

And if unacceptable, how about at least making 
"rootfs_populate_volatile_cache" available as a sort of library method so it 
doesn't get repeated at each image recipe?

On 12-08-15 09:00, Mike Looijmans wrote:
> Currently populate-volatile.sh will only run when "readonly-rootfs" is
> selected.
>
> Running this script is very useful even on read/write root filesystems,
> because it reduces the number of "fixup" actions at first boot of the
> device. That not only reduces boot time, it also reduces the flash space
> usage. Also, when the system happens to have a read-only filesystem
> because for example the "read-only" switch of the SD card was set, or
> because the filesystem had errors on it, it will still be able to boot.
>
> I've been manually adding these lines to each and every image recipe I've
> used, so I guess it's time to move this into core.
>
> Signed-off-by: Mike Looijmans <mike.looijmans at topic.nl>
> ---
>   meta/classes/image.bbclass | 18 +++++++++++++-----
>   1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
> index ff2ed0d..68deb84 100644
> --- a/meta/classes/image.bbclass
> +++ b/meta/classes/image.bbclass
> @@ -185,6 +185,9 @@ ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains_any("IMAGE_FEATURES", [ 'deb
>   # Create /etc/timestamp during image construction to give a reasonably sane default time setting
>   ROOTFS_POSTPROCESS_COMMAND += "rootfs_update_timestamp ; "
>
> +# Create the volatile cache. Required for read-only rootfs, useful for all sysvinit systems to reduce writes to the system
> +ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("DISTRO_FEATURES", "sysvinit", "rootfs_populate_volatile_cache;", "", d)}'
> +
>   # Tweak the mount options for rootfs in /etc/fstab if read-only-rootfs is enabled
>   ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "read_only_rootfs_hook; ", "",d)}'
>
> @@ -216,6 +219,16 @@ do_rootfs[cleandirs] += "${S}"
>   # task, so that we have a single fakeroot context for the whole process.
>   do_rootfs[umask] = "022"
>
> +
> +# Run populate-volatile.sh at rootfs time to set up basic files and
> +# directories to reduce writes at first boot and to support read-only
> +# rootfs.
> +rootfs_populate_volatile_cache() {
> +		if [ -x ${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh ]; then
> +			${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh
> +		fi
> +}
> +
>   # A hook function to support read-only-rootfs IMAGE_FEATURES
>   read_only_rootfs_hook () {
>   	# Tweak the mount option and fs_passno for rootfs in fstab
> @@ -226,11 +239,6 @@ read_only_rootfs_hook () {
>   		if [ -e ${IMAGE_ROOTFS}/etc/default/rcS ]; then
>   			sed -i 's/ROOTFS_READ_ONLY=no/ROOTFS_READ_ONLY=yes/' ${IMAGE_ROOTFS}/etc/default/rcS
>   		fi
> -		# Run populate-volatile.sh at rootfs time to set up basic files
> -		# and directories to support read-only rootfs.
> -		if [ -x ${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh ]; then
> -			${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh
> -		fi
>   		# If we're using openssh and the /etc/ssh directory has no pre-generated keys,
>   		# we should configure openssh to use the configuration file /etc/ssh/sshd_config_readonly
>   		# and the keys under /var/run/ssh.
>



Kind regards,

Mike Looijmans
System Expert

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