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RedBear-OS/local/recipes/libs/libinput/source/doc/user/trackpoints.rst
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vasilito f31522130f fix: comprehensive boot warnings and exceptions — fixable silenced, unfixable diagnosed
Build system (5 gaps hardened):
- COOKBOOK_OFFLINE defaults to true (fork-mode)
- normalize_patch handles diff -ruN format
- New 'repo validate-patches' command (25/25 relibc patches)
- 14 patched Qt/Wayland/display recipes added to protected list
- relibc archive regenerated with current patch chain

Boot fixes (fixable):
- Full ISO EFI partition: 16 MiB → 1 MiB (matches mini, BIOS hardcoded 2 MiB offset)
- D-Bus system bus: absolute /usr/bin/dbus-daemon path (was skipped)
- redbear-sessiond: absolute /usr/bin/redbear-sessiond path (was skipped)
- daemon framework: silenced spurious INIT_NOTIFY warnings for oneshot_async services (P0-daemon-silence-init-notify.patch)
- udev-shim: demoted INIT_NOTIFY warning to INFO (expected for oneshot_async)
- relibc: comprehensive named semaphores (sem_open/close/unlink) replacing upstream todo!() stubs
- greeterd: Wayland socket timeout 15s → 30s (compositor DRM wait)
- greeter-ui: built and linked (header guard unification, sem_compat stubs removed)
- mc: un-ignored in both configs, fixed glib/libiconv/pcre2 transitive deps
- greeter config: removed stale keymapd dependency from display/greeter services
- prefix toolchain: relibc headers synced, _RELIBC_STDLIB_H guard unified

Unfixable (diagnosed, upstream):
- i2c-hidd: abort on no-I2C-hardware (QEMU) — process::exit → relibc abort
- kded6/greeter-ui: page fault 0x8 — Qt library null deref
- Thread panics fd != -1 — Rust std library on Redox
- DHCP timeout / eth0 MAC — QEMU user-mode networking
- hwrngd/thermald — no hardware RNG/thermal in VM
- live preload allocation — BIOS memory fragmentation, continues on demand
2026-05-05 20:20:37 +01:00

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.. _trackpoints:
==============================================================================
Trackpoints and Pointing Sticks
==============================================================================
This page provides an overview of trackpoint handling in libinput, also
referred to as Pointing Stick or Trackstick. The device itself is usually a
round plastic stick between the G, H and B keys with a set of buttons below
the space bar.
.. figure:: button-scrolling.svg
:align: center
A trackpoint
libinput always treats the buttons below the space bar as the buttons that
belong to the trackpoint even on the few laptops where the buttons are not
physically wired to the trackpoint device anyway, see :ref:`t440_support`.
.. _trackpoint_buttonscroll:
------------------------------------------------------------------------------
Button scrolling on trackpoints
------------------------------------------------------------------------------
Trackpoint devices have :ref:`button_scrolling` enabled by default. This may
interfer with middle-button dragging, if middle-button dragging is required
by a user then button scrolling must be disabled.
.. _trackpoint_range:
------------------------------------------------------------------------------
Motion range on trackpoints
------------------------------------------------------------------------------
It is difficult to associate motion on a trackpoint with a physical
reference. Unlike mice or touchpads where the motion can be
measured in mm, the trackpoint only responds to pressure. Without special
equipment it is impossible to measure identical pressure values across
multiple laptops.
The values provided by a trackpoint are motion deltas, usually corresponding
to the pressure applied to the trackstick. For example, pressure towards the
screen on a laptop provides negative y deltas. The reporting rate increases
as the pressure increases and once events are reported at the maximum rate,
the delta values increase. The figure below shows a rough illustration of
this concept. As the pressure
decreases, the delta decrease first, then the reporting rate until the
trackpoint is in a neutral state and no events are reported. Trackpoint data
is hard to generalize, see
`Observations on trackpoint input data
<https://who-t.blogspot.com/2018/06/observations-on-trackpoint-input-data.html>`_
for more details.
.. figure:: trackpoint-delta-illustration.svg
:align: center
Illustration of the relationship between reporting rate and delta values on a trackpoint
The delta range itself can vary greatly between laptops, some devices send a
maximum delta value of 30, others can go beyond 100. However, the useful
delta range is a fraction of the maximum range. It is uncomfortable to exert
sufficient pressure to even get close to the maximum ranges.
libinput provides a :ref:`Magic Trackpoint Multiplier
<trackpoint_multiplier>` to normalize the trackpoint input data.