Re: [oe-core][PATCHv9 0/6] Display manager proposal for x11 and wayland

[Randolph Sapp <rs@ti.com>]

On Thu Sep 18, 2025 at 5:39 PM CDT, Randolph Sapp via lists.openembedded.org wrote:
> On Thu Sep 18, 2025 at 5:35 PM CDT, Joshua Watt wrote:
>> On Thu, Sep 18, 2025 at 4:31 PM Randolph Sapp <rs@ti.com> wrote:
>>>
>>> On Thu Sep 18, 2025 at 5:25 PM CDT, Joshua Watt wrote:
>>> > On Thu, Sep 18, 2025 at 3:49 PM Randolph Sapp via
>>> > lists.openembedded.org <rs=ti.com@lists.openembedded.org> wrote:
>>> >>
>>> >> From: Randolph Sapp <rs@ti.com>
>>> >>
>>> >> We've recently run into some issues with weston-init attempting to start Weston
>>> >> prior to all drm devices being registered. There's not really a good, scriptable
>>> >> mechanism to listen in to device registration events that works with the
>>> >> existing weston-init package. Well, at least one that doesn't involve polling
>>> >> files or introducing more dependency on the init system being used.
>>> >
>>> > It's not clear how switching to emptty actually solves that problem; I
>>> > don't see anything in my (brief) look at the emptty code that would
>>> > lead me to believe it actually cares about any drm devices being
>>> > present or handles devices showing up dynamically. Can you maybe
>>> > elaborate more on this?
>>>
>>> It doesn't currently have any tests to wait for the DRM device. I still need to
>>> look into adding that, but what it currently does is add a retry event counter
>>> and a small delay between retries that is better than the current console
>>> implementations. Especially considering authentication is handled separately
>>> from this retry process.
>>>
>>> By centralizing display manager specific code, common checks and fallback logic
>>> can be more easily implemented in the future. I'm hoping this lays the
>>> groundwork to let me address some other issues I've seen in multi-card
>>> environments as well.
>>
>> For the systemd parts, is it also possible to solve this with e.g.
>>
>> Requires=dev-dri-card0.device
>> After=dev-dri-card0.device
>>
>> (or similar) ? Seems like anything emptty would be doing would be a
>> reimplementation of the logic that already exists in systemd to do
>> that.
>
> It gets messy. A udev rule needs to be made to make systemd track that device.
> In a multi-card environment a device without an actual display may be picked.
> Systemd cannot directly solve the issue on it's own.

Additionally, there are more init systems supported here than just systemd...

>>> >> I also see there is also a lot of scripting around starting X11,
>>> >> xserver-nodm-init, that (from my limited review) should experience the same
>>> >> issue.
>>> >>
>>> >> I'd like to introduce the following display manager for oe-core, emptty [1].
>>> >> This display manager is, as described upstream, a "Dead simple CLI Display
>>> >> Manager on TTY". It supports both x11 and wayland sessions, with togglable build
>>> >> parameters to completely remove x11 and pam dependencies. It's licensed MIT,
>>> >> which shouldn't be an issue for any users. (It is written in Go, if you have
>>> >> opinions about that.)
>>> >>
>>> >> With this, both weston-init and the xserver-nodm-init packages can be re-tuned
>>> >> to leverage this display manager and simply add a user and emptty config for an
>>> >> autologin session. This can resolve the current behavior across init systems
>>> >> without additional scripting, and move some development out of this layer.
>>> >>
>>> >> This lists myself as a maintainer of emptty as well as xserver-nodm-init and
>>> >> xuser-account since these are currently unassigned and I've reworked them
>>> >> significantly here.
>>> >>
>>> >> Sorry for the delay on this series. I found a few bugs in emptty that I wanted
>>> >> to address before submitting this officially.
>>> >>
>>> >> [1] https://github.com/tvrzna/emptty
>>> >>
>>> >> v2:
>>> >>         - Address spelling issues in commit messages
>>> >>         - Attempt to resolve some test related issues with weston
>>> >>         - Add additional logs to X11 related tests
>>> >> v3:
>>> >>         - Reset AUTOLOGIN_MAX_RETRY to the default value of 2. When running
>>> >>           under QEMU the first auth attempt almost always fails.
>>> >> v4:
>>> >>         - Add a tmpfile entry for the x11 domain socket directory.
>>> >>         - Remove some scripts associated with weston-init that were being
>>> >>           shipped with weston
>>> >> v5:
>>> >>         - Move tmpfile data to individual files
>>> >>         - Add explicit entries for these in the FILES variable
>>> >> v6:
>>> >>         - Do not attempt to ship a tmpfiles.d entry in libx11
>>> >> v7:
>>> >>         - Include a backported fix for go/runtime to address segfault issues
>>> >>           reported on x86 platforms in previous revisions
>>> >> v8:
>>> >>         - Sign-off backported patch
>>> >> v9:
>>> >>         - Resolve merge conflict in maintainers file
>>> >>
>>> >> Randolph Sapp (6):
>>> >>   libx11: create tmpfile dir for x11 domain socket
>>> >>   go: fix sigaction usage on i386 platforms
>>> >>   emptty: add version 0.14.0
>>> >>   weston-init: convert to virtual-emptty-conf
>>> >>   weston: remove deprecated weston-start scripts
>>> >>   xserver-nodm-init: convert to virtual-emptty-conf
>>> >>
>>> >>  .../conf/distro/include/default-providers.inc |   1 +
>>> >>  meta/conf/distro/include/maintainers.inc      |   6 +-
>>> >>  meta/lib/oeqa/runtime/cases/weston.py         |  18 +-
>>> >>  meta/lib/oeqa/runtime/cases/xorg.py           |   8 +
>>> >>  meta/recipes-devtools/go/go-1.25.0.inc        |   1 +
>>> >>  ...ng-cgo-on-386-call-C-sigaction-funct.patch | 248 ++++++++++++
>>> >>  meta/recipes-graphics/emptty/emptty-conf.bb   |  14 +
>>> >>  meta/recipes-graphics/emptty/emptty.inc       |  26 ++
>>> >>  .../recipes-graphics/emptty/emptty/emptty.tab |   1 +
>>> >>  meta/recipes-graphics/emptty/emptty/pamconf   |  10 +
>>> >>  meta/recipes-graphics/emptty/emptty_0.14.0.bb |  53 +++
>>> >>  meta/recipes-graphics/wayland/weston-init.bb  |  61 +--
>>> >>  .../wayland/weston-init/emptty.conf           |  77 ++++
>>> >>  .../recipes-graphics/wayland/weston-init/init |  54 ---
>>> >>  .../wayland/weston-init/weston-autologin      |  11 -
>>> >>  .../wayland/weston-init/weston-socket.sh      |  20 -
>>> >>  .../wayland/weston-init/weston-start          |  76 ----
>>> >>  .../wayland/weston-init/weston.env            |   0
>>> >>  .../wayland/weston-init/weston.service        |  71 ----
>>> >>  .../wayland/weston-init/weston.socket         |  14 -
>>> >>  .../weston/systemd-notify.weston-start        |   9 -
>>> >>  .../wayland/weston/xwayland.weston-start      |   6 -
>>> >>  .../recipes-graphics/wayland/weston_14.0.2.bb |  10 -
>>> >>  .../x11-common/xserver-nodm-init/X11/Xsession |  38 --
>>> >>  .../X11/Xsession.d/13xdgbasedirs.sh           |  19 -
>>> >>  .../X11/Xsession.d/89xdgautostart.sh          |   7 -
>>> >>  .../X11/Xsession.d/90XWindowManager.sh        |   7 -
>>> >>  .../x11-common/xserver-nodm-init/Xserver      |  25 --
>>> >>  .../xserver-nodm-init/capability.conf         |   2 -
>>> >>  .../xserver-nodm-init/default.desktop         |   5 +
>>> >>  .../xserver-nodm-init/emptty.conf.in          |  77 ++++
>>> >>  .../xserver-nodm-init/gplv2-license.patch     | 355 ------------------
>>> >>  .../x11-common/xserver-nodm-init/xserver-nodm |  75 ----
>>> >>  .../xserver-nodm-init/xserver-nodm.conf.in    |   7 -
>>> >>  .../xserver-nodm-init/xserver-nodm.service.in |  11 -
>>> >>  .../x11-common/xserver-nodm-init_3.0.bb       |  57 +--
>>> >>  meta/recipes-graphics/xorg-lib/libx11/99_x11  |   1 +
>>> >>  .../xorg-lib/libx11_1.8.12.bb                 |  15 +-
>>> >>  .../user-creation/xuser-account_0.1.bb        |   3 +-
>>> >>  39 files changed, 581 insertions(+), 918 deletions(-)
>>> >>  create mode 100644 meta/recipes-devtools/go/go/0001-runtime-when-using-cgo-on-386-call-C-sigaction-funct.patch
>>> >>  create mode 100644 meta/recipes-graphics/emptty/emptty-conf.bb
>>> >>  create mode 100644 meta/recipes-graphics/emptty/emptty.inc
>>> >>  create mode 100644 meta/recipes-graphics/emptty/emptty/emptty.tab
>>> >>  create mode 100644 meta/recipes-graphics/emptty/emptty/pamconf
>>> >>  create mode 100644 meta/recipes-graphics/emptty/emptty_0.14.0.bb
>>> >>  create mode 100644 meta/recipes-graphics/wayland/weston-init/emptty.conf
>>> >>  delete mode 100644 meta/recipes-graphics/wayland/weston-init/init
>>> >>  delete mode 100644 meta/recipes-graphics/wayland/weston-init/weston-autologin
>>> >>  delete mode 100755 meta/recipes-graphics/wayland/weston-init/weston-socket.sh
>>> >>  delete mode 100755 meta/recipes-graphics/wayland/weston-init/weston-start
>>> >>  delete mode 100644 meta/recipes-graphics/wayland/weston-init/weston.env
>>> >>  delete mode 100644 meta/recipes-graphics/wayland/weston-init/weston.service
>>> >>  delete mode 100644 meta/recipes-graphics/wayland/weston-init/weston.socket
>>> >>  delete mode 100644 meta/recipes-graphics/wayland/weston/systemd-notify.weston-start
>>> >>  delete mode 100644 meta/recipes-graphics/wayland/weston/xwayland.weston-start
>>> >>  delete mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/X11/Xsession
>>> >>  delete mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/X11/Xsession.d/13xdgbasedirs.sh
>>> >>  delete mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/X11/Xsession.d/89xdgautostart.sh
>>> >>  delete mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/X11/Xsession.d/90XWindowManager.sh
>>> >>  delete mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/Xserver
>>> >>  delete mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/capability.conf
>>> >>  create mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/default.desktop
>>> >>  create mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/emptty.conf.in
>>> >>  delete mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/gplv2-license.patch
>>> >>  delete mode 100755 meta/recipes-graphics/x11-common/xserver-nodm-init/xserver-nodm
>>> >>  delete mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/xserver-nodm.conf.in
>>> >>  delete mode 100644 meta/recipes-graphics/x11-common/xserver-nodm-init/xserver-nodm.service.in
>>> >>  create mode 100644 meta/recipes-graphics/xorg-lib/libx11/99_x11
>>> >>
>>> >> --
>>> >> 2.51.0
>>> >>
>>> >>
>>> >> 
>>> >>
>>>