Add timezone info package

[Eeems]

The reMarkable doesn't come with the full set of timezone information. So timezones listed by timedatectl as on the device are not actually selectable. We should add a package that contains the full set and likely install it by default.

[matteodelabre]

Note that the zoneinfo-* packages from Entware (of which zoneinfo-asia and zoneinfo-europe are installed by default) already install timezone information to /opt/share/timezone/. So we could simply defer to these packages by symlinking /usr/share/timezone to /opt/share/timezone. We also need to install zoneinfo-core for this to work (strangely, it is not installed by default), otherwise key files like /opt/share/timezone/zone.tab are missing.

[Eeems]

Hmm, but does this work nicely with timedatectl?

[matteodelabre]

Just tested it on my device and it works (both list-timezones and set-timezone).

[Eeems]

So I guess the tzdata package isn't needed?

[MechEng70]

RM2 here (without installing anything):

reMarkable: ~/ timedatectl set-timezone America/Los_Angeles
reMarkable: ~/ timedatectl
                      Local time: Tue 2021-01-05 08:12:21 PST
                  Universal time: Tue 2021-01-05 16:12:21 UTC
                        RTC time: Tue 2021-01-05 16:12:22
                       Time zone: America/Los_Angeles (PST, -0800)
       System clock synchronized: no
systemd-timesyncd.service active: yes
                 RTC in local TZ: no
reMarkable: ~/

[matteodelabre]

So I guess the tzdata package isn't needed?

@Eeems Yes. It seems to be redundant with the Entware packages. As an added bonus, installing timezone info to /opt saves space on the root partition.

RM2 here (without installing anything)

@MechEng70 America/Los_Angeles is shipped by default with the reMarkable. Try another timezone like Africa/Abidjan which although it is listed in timedatectl list-timezones should give you an error.

[Eeems]

Does zoneinfo-core contain zdump or zic?

[matteodelabre]

It looks like zoneinfo-* packages only contain zone definitions and no binaries.

[MechEng70]

@matteodelabre Confirmed that "Africa/Abidjan" does give an error on RM2.

reMarkable: ~/ timedatectl set-timezone Africa/Abidjan
Failed to set time zone: Invalid time zone 'Africa/Abidjan'

[matteodelabre]

@MechEng70 Thanks for testing!

[Eeems]

It looks like zoneinfo-* packages only contain zone definitions and no binaries.

Alright I'll take a quick look to see if entware has them elsewhere, if not I'll rename the package and only include those binaries.

[matteodelabre]

To make everything work smoothly, we’ll also need to create the symlink from /usr/share/timezone to /opt/share/timezone in the bootstrap script. But since we don’t have an uninstall script (maybe we ought to have one?), I’m not sure what is the best way to restore the rM-provided timezone data.

[Eeems]

The best way would be to pull it directly from an update archive to be honest. Perhaps we should be using a bind mount instead of symlinking? That way we don't have to worry about restoring?

[matteodelabre]

Good idea, I forgot about bind mounts. I'll open a PR to add this to the install script tomorrow.

[Eeems]

Good idea, I forgot about bind mounts. I'll open a PR to add this to the install script tomorrow.

Which PR is that ;P

[matteodelabre]

Is it tomorrow yet?

[Eeems]

Opened #213