T2 PalmReject

This project aims to improve palm rejection functionality for those running t2linux on their macbooks.

Grabs the physical trackpad, filters palm-shaped contacts, and forwards accepted contacts through a virtual multitouch touchpad so libinput keeps handling pointer acceleration, two-finger scrolling, clicking, and gestures.

Compatibility

Currently tested on:

• Hardware: 2020 Intel MacBook Air (A2179)
• Distro: arch
• Desktop Envio: Hyprland
• Input Stack: evdev, uinput, and libinput
• Service Manager: systemd

Safety warning

PalmReject exclusively grabs the real trackpad while it is running. If the virtual touchpad fails, pointer input can appear to stop.

Stop palmreject:

sudo systemctl stop palmreject.service

Remove it completely:

sudo ./uninstall.sh

Dependencies

Install standard Arch build tools and libinput utilities:

sudo pacman -S --needed base-devel libinput

brightnessctl is optional. When present and the tested keyboard-backlight device is detected, the installer can restore the keyboard backlight after resume.

Installation

Extract the archive and enter the directory:

tar -xzf T2_PalmReject-v1.0.0.tar.gz
cd T2_PalmReject-v1.0.0

First run a non-destructive check:

./install.sh --dry-run

Then install:

sudo ./install.sh

The installer:

1. Builds palmreject from source
2. Detects the Apple internal trackpad using stable /dev/input/by-id or /dev/input/by-path links
3. Writes /etc/palmreject.conf
4. Installs /usr/local/bin/palmreject
5. Installs and enables palmreject.service
6. Installs a suspend/resume hook that stops the service before sleep and restarts it after wake
7. Loads uinput and configures it to load at boot

To choose the device manually:

sudo ./install.sh --device /dev/input/by-id/YOUR-TRACKPAD-event-mouse

To skip keyboard-backlight restoration:

sudo ./install.sh --no-backlight

Service commands

systemctl status palmreject.service
sudo systemctl restart palmreject.service
sudo systemctl stop palmreject.service
journalctl -u palmreject.service -b

Uninstall

From the source directory:

sudo ./uninstall.sh

Preserve /etc/palmreject.conf while removing everything else:

sudo ./uninstall.sh --keep-config

Manual build

make
sudo ./palmreject /dev/input/by-id/YOUR-TRACKPAD-event-mouse

Stop the manual process with Ctrl+C before starting the systemd service.

Project layout

.
├── include/
│   └── virtual_touchpad.h
├── scripts/
│   └── detect-trackpad.sh
├── src/
│   ├── main.c
│   └── virtual_touchpad.c
├── systemd/
│   ├── palmreject.service
│   └── palmreject-sleep
├── install.sh
├── uninstall.sh
├── Makefile
├── VERSION
├── LICENSE
└── README.md

Current Limitations

• coordinate ranges and palm thresholds are hardcoded for the tested Apple trackpad
• limited support for thumbing
• pinch zooming is a little buggy

Architecture

Physical Apple trackpad
        |
        | EVIOCGRAB
        v
T2 PalmReject classifier
        |
        | fingers forwarded; palms globally blocked
        v
Virtual multitouch touchpad
        |
        v
libinput -> compositor/desktop

License

T2 PalmReject is licensed under the GNU General Public License v3.0 only. See LICENSE for the complete terms.

Copyright (C) 2026 Ryan C.

Developed by Ryan C. with assistance from ChatGPT during prototyping and packaging.