[OE-core] [PATCH] rootfs-postcommands: generate /var/lib/systemd/clock

[Peter Kjellerstedt]

> -----Original Message-----
> From: openembedded-core-bounces at lists.openembedded.org
> [mailto:openembedded-core-bounces at lists.openembedded.org] On Behalf Of
> Khem Raj
> Sent: den 16 juni 2016 16:38
> To: Jan Remmet
> Cc: openembedded-core at lists.openembedded.org
> Subject: Re: [OE-core] [PATCH] rootfs-postcommands: generate
> /var/lib/systemd/clock
> 
> 
> > On Jun 16, 2016, at 7:17 AM, Jan Remmet <J.Remmet at phytec.de> wrote:
> >
> > On Wed, Jun 15, 2016 at 12:14:17PM -0700, Khem Raj wrote:
> >>
> >>> On Jun 15, 2016, at 6:36 AM, Jan Remmet <J.Remmet at phytec.de> wrote:
> >>>
> >>> systemd timesyncd check /var/lib/systemd/clock instead of
> >>> /etc/timestamp.
> >>> If this file is missing it defaults to TIME_EPOCH. It's set while
> >>> configuring systemd.
> >>>
> >>> Signed-off-by: Jan Remmet <j.remmet at phytec.de>
> >>> ---
> >>> meta/classes/rootfs-postcommands.bbclass | 6 ++++++
> >>> 1 file changed, 6 insertions(+)
> >>>
> >>> diff --git a/meta/classes/rootfs-postcommands.bbclass
> b/meta/classes/rootfs-postcommands.bbclass
> >>> index db8b551..0c7b764 100644
> >>> --- a/meta/classes/rootfs-postcommands.bbclass
> >>> +++ b/meta/classes/rootfs-postcommands.bbclass
> >>> @@ -234,6 +234,12 @@ python write_image_manifest () {
> >>> # sane default time setting
> >>> rootfs_update_timestamp () {
> >>> 	date -u +%4Y%2m%2d%2H%2M%2S >${IMAGE_ROOTFS}/etc/timestamp
> >>> +
> >>> +	if ${@bb.utils.contains("DISTRO_FEATURES", "systemd", "true",
> "false", d)}; then
> >>> +		# touch needs timestamp as [[CC]YY]MMDDhhmm[.ss]
> >>> +		TS=$(sed 's/[.]*/&./13' ${IMAGE_ROOTFS}/etc/timestamp)
> >>> +		touch -t $TS ${IMAGE_ROOTFS}/var/lib/systemd/clock
> >>> +	fi
> >>> }
> >>
> >> i wonder if this will work with read only rootfs.
> > I found no special handling for systemd and /var/lib if
> > IMAGE_FEATURES read-only-rootfs is used.

If read-only-rootfs is used, then /var/lib is a bind mount to 
/var/volatile/lib (which is a tmpfs). This is handled by the
volatile-binds recipe.

> > If timesyncd didn't find /var/lib/systemd/clock it defaults to the
> > configure time value und try to write /var/lib/systemd/clock. On 
> > read-only it will silently fail.
> > So I don't see a problem here.
> 
> It fixes one case when rootfs is r/w but create another behavior when
> its r/o in r/o case /var/lib/systemd must be mounted r/w during boot.
> So the timesyncd service should check for that directory to exist I 
> have a hunch if thats checked then this patch may not be needed
> 
> >
> > Jan

//Peter