Gentoo on a GPD Pocket 3

Introduction

The GPD Pocket 3 represents the third generation of GPD’s ultra-mobile PC (UMPC) series, featuring Intel Tiger Lake architecture and a unique convertible tablet design. This manual is intended to help users configure Gentoo distribution of the GNU/Linux operating system for GPD Pocket 3 handheld computer.

Unlike mainstream laptops, the GPD Pocket 3 presents specific challenges for Linux users: portrait-oriented display requiring rotation, specialized input devices including touchscreen and digitizer, and unique hardware components that require careful kernel configuration. This guide addresses these challenges with proven solutions tested on real hardware.

It’s supposed that users are skilled enough to install bare system from stage, compile kernel from source code, apply patches, and have experience with Gentoo’s Portage system. Basic familiarity with X11 configuration and hardware troubleshooting is also recommended.

Hardware Compatibility: This guide has been tested with the Intel i3-1125G4 variant. Users with the Intel N6000 model may need to adapt certain configurations as noted throughout the document.

This article and all information and products in it are provided on an "as is" basis, without warranty of any kind, either express or implied. Your use of this article is at your own risk.

Content

Hardware info

Brief hardware description from the manufacturer: GPD Pocket 3 (local backup of the page).

Type Name
Technical info
CPU Intel® Core™ i3-1125G4 (Tiger Lake) Base frequency: 0,9GHz@12W, 2.0Ghz@28W; Max frequency: 3.7GHz/1 core, 3.3Ghz/all cores; 4 cores, 8 threads; TDP: 12-28W; Features: x86-64, SSE4.2, AVX512, AES, IVT; L2 cache: 8MB. [1], [2], [3]
RAM Micron Technology 16GB dual channel, LPDDR4X-4267
Video Intel UHD Graphics G4 (Tiger Lake) EU: 48, Clock speed: 0.4-1.25Ghz; 600-1100 GFLOPS; OpenGL support: 4.6; Multimedia codecs (decode) [4] : MPEG-2, MPEG-4 AVC, VC-1 / WMV9, HEVC, VP9, AV-1, JPEG. Device id: 8086:9a78 (rev 01); [5], [6]
Storage device Custom: WD Black SN850X M.2 NVME SSD Capacity: 2TB; Seq. R/W speed: 2.6/3.4 GB/s;
Audio Realtek Semiconductor Co. ALC269VC 4 channels, 24-bit I/O; DAC max sample rate: 192kHz; EAX 1.0 & 2.0, Direct Sound 3D, A3D; Device id: 8086:a0c8 [7]
Ethernet Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller Speed: 10M/100M/1Gbps/2.5Gbps; Device id: 10ec:8125 (rev 05); [8]
WiFi & Bluetooth Intel® Wi-Fi 6E AX210 Bands: 2.4, 5, 6GHz; Protocols: 802.11ax; Max speed: 2.4 Gbps; Bluetooth Version 5.3; PCI Device id: 8086:2725 (rev 1a); USB Device id: 8087:0032; [9]
Web camera Alcor Micro Corp. USB 2.0 Camera Maximum resolution of 1600×1200 at 30fps; Device id: 058f:5608;
Accelerometer Memsic MXC4005XC 3-Axis Accelerometer
Keyboard & touchpad HAILUCK CO.,LTD USB KEYBOARD Mouse Device id: 258a:000c
Touchscreen & digitizer Goodix GXTP7380 Device id: 27c6:0113, compatible with Microsoft Surface Pen
Fingerprint reader Focaltech FTE3600 Connected via SPI bus
Thunderbolt 4 Intel Corporation Tiger Lake-LP Thunderbolt 4 USB Controller Device id: 8086:9a13;

References

  1. Intel® Core™ i3-1125G4 Processor
  2. Tiger Lake – Wikipedia
  3. Intel Core i3-1125G4 Processor – Benchmarks and Specs – NotebookCheck.net Tech
  4. Intel Graphics Technology – Wikipedia
  5. List of Intel graphics processing units – Wikipedia
  6. Intel Tiger Lake-U Xe Graphics G4 48 EUs GPU – Benchmarks and Specs – NotebookCheck.net Tech
  7. ALC269 HIGH DEFINITION AUDIO CODEC WITHE MBEDDED CLASS-D SPEAKER AMPLIFIER DATASHEET
  8. RTL8168 INTEGRATED GIGABIT ETHERNET CONTROLLER FOR PCI EXPRESS APPLICATIONS DATASHEET
  9. Intel® Wi-Fi 6E AX210

Logs

Linux support summary

Subsystem Feature Status
Input Keyboard Works perfectly
Optical pointer Works perfectly
Touchscreen Works perfectly
Digitizer Works perfectly
Digitizer pen buttons Works perfectly
Video Integrated display Works perfectly
2D graphics Works perfectly
3D acceleration Works perfectly
Video decoding acceleration Works perfectly
HDMI output Minor issues
Audio Internal speaker Works perfectly
Microphone Works perfectly
Audio out jack Works perfectly
Headphones mute speaker Works perfectly
Networking Ethernet Works perfectly
WiFi Works perfectly
Bluetooth Untested
ACPI Lid button Works perfectly
Power button Works perfectly
Brightness control Works perfectly
AC and battery Works perfectly
Power management Suspend to RAM Works perfectly
Suspend to disk Works perfectly
CPU frequency scaling Works perfectly
Other Web camera Works perfectly
Fingerprint reader Not supported

Kernel

The kernel config for version 6.15.4 is available here. Few notes regarding the kernel config:

  • It’s optimized for GPD Pocket 3 (i3-1125G4). Most options not required by this device are turned off. The total number of enabled options is 1450, the size of the compiles binary image is 12M. You may need to enable additional options like filesystems or drivers for peripheral devices.
  • This config produces monolith kernel, which does not require any modules, firmwares or even a command line. But prior building this kernel you need install the firmware files, which are provided by these two packages:
    • sys-kernel/linux-firmware. In order to install only the firmware files which are relevant for GPD Pocket 3, enable these two USE flags: redistributable savedconfig and save this file as /etc/portage/savedconfig/sys-kernel/linux-firmware/linux-firmware.conf
    • net-wireless/wireless-regdb
  • Mitigation of Spectre and Meltdown vulnerabilities is disabled (CONFIG_PAGE_TABLE_ISOLATION). Consider for yourself what is more important for you: performance of security.
  • This config assumes that nvme0n1p5 is the root partition and nvme0n1p4 is the swap partition. If your partition layout is different, you will need to edit these parameters:
    • CONFIG_CMDLINE="root=/dev/nvme0n1p5 fbcon=rotate:1 video=DSI-1:panel_orientation=right_side_up quiet i915.enable_guc=3"
    • CONFIG_PM_STD_PARTITION="/dev/nvme0n1p4"

Please note that systems equipped with the Intel N6000 processor require a tailored kernel configuration and specific firmware binaries: install the appropriate Intel N6000 microcode package (e.g., intel-microcode for N6000), and adjust the P-State driver settings to match the lower-power P-Core performance characteristics, etc.

Kernel Version Recommendation

Users running kernels older than 6.15.4 have reported the following issues, all resolved in 6.15.4 and later releases:

  1. X11 video stability – Xorg server crashes in applications when 3D acceleration is enabled, while disabling 3D results in unacceptably slow performance on Tiger Lake platforms. In order for the video subsystem to work stably and with full functionality in the X server, a recent xe driver is required (as described in the Video section)

  2. PCIe DMA timeouts – Problems on the Realtek RTL8125 Ethernet controller 1.

  3. Suspend/resume hangs Erratic behavior causing hangs during S3 entry 2.

  4. SOF audio routing Incomplete sound routing with ALC269 codecs under SOF, resulting in no audio output 3.

Therefore it is strongly recommended to build and install kernel version 6.15.4 or newer to ensure full hardware compatibility.

Booting the kernel

Since the described kernel does not require a command line, you can boot it directly from the EFI firmware. You no longer need to install and configure a bootloader.

mount /dev/nvme0n1p1 /mnt/boot
cp arch/x86_64/boot/bzImage /mnt/boot/EFI/Boot/bootx64.efi
umount /mnt/boot
efibootmgr -c -d /dev/nvme0n1 -p1 -L 'Gentoo' -l '\EFI\Boot\bootx64.efi'

After that you can make Gentoo the default boot option via editing BIOS setting Boot -> Boot Option Priorities.

Input

There are various xorg input device drivers. libinput is one of them, and it’s the default driver in Gentoo. This driver works fine with GPD Pocket 3.

In order to use this driver, add ‘libinput’ to the INPUT_DEVICES variable, see make.conf as example.

Keyboard

Down below you can see xorg.conf.d file for the keyboard.

10keyboard.conf

    Section "InputClass"
        Identifier          "keyboard-all"
        Driver              "libinput"
        Option              "XkbRules"                  "evdev"
        Option              "XkbModel"                  "pc105"
        Option              "XkbLayout"                 "us,ru"
        Option              "XkbVariant"                ",winkeys"
        Option              "XkbOptions"                "grp:alt_shift_toggle,terminate:ctrl_alt_bksp"
        MatchIsKeyboard     "on"
        MatchDevicePath     "/dev/input/event*"
    EndSection

Fn+Printsc and Fn+Insert by default generate correct key symbol for display brightness control: XF86MonBrightnessUp and XF86MonBrightnessDown;
Fn+[, Fn+] and Fn+\ г generate standard key symbols for audio control: XF86AudioRaiseVolume, XF86AudioLowerVolume and XF86AudioMute;

All we need to do is to assign proper actions to the symnames. The rc.xml is an example of such bindings. This configuration file has some additional key binding, which you may find interesting:

Alt+d– Toggles DPMS state of connected displays via xset. See dpms.sh for details.
The Power button generates XF86PowerOff as expected. This key code is assigned to show an information dialog (tray.sh), which contains current time and date, battery status and level, brightness, CPU frequencies and governors, etc.

            13.08 Wednesday 13:11

    Paused: 01-5 Jahre (Single Version).mp3
    Battery: Discharging, 75%, 07:10:58 remaining
    Brightness: 25
    Temp: CPU 36|33|37|33°C, SSD 37°C, Eth 37°C
    Freq: 3.17GHz|2.92GHz|3.07GHz|2.71GHz, powersave
    RAM: 76% free
    Network: eth0 wlan0, wireless is on

Fn+- generates the Menu key symbol.
Fn+= is the fan switch. It is 100% hardware and does not generate a scancode, ACPI or udev event.
Fn+space enables/disables keyboard backlight. It is also 100% hardware and does not require any software configurations.
Del key during boot enters BIOS setup.
Fn+6 (or F7) during boot opens boot device selection menu.

Touchscreen

Down below you can see xorg.conf.d file for the touchscreen.

22touchscreen.conf

    Section "InputClass"
      Identifier    "calibration"
      Driver        "wacom"
      MatchProduct  "GXTP7380"
      Option        "TransformationMatrix" "0 1 0 -1 0 1 0 0 1"
      Option        "Button2" "3"
    EndSection

If you want to change the touchscreen orientation automatically, see the Accelerometer section.

Digitizer & Stylus

The digitizer GXTP7380 works out of the box with the kernel version 6.15.4 and the wacom X11 input driver. Down below you can see xorg.conf.d file for the digitizer.

23pen.conf

    Section "InputClass"
      Identifier "Wacom N-Trig class"
      MatchProduct "HID 1b96:0001|N-Trig Pen|N-Trig DuoSense|27C6:0113"
      MatchDevicePath "/dev/input/event*"
      Driver "wacom"
      Option "Button2" "3"
    EndSection

Pressure sensitivity also works fine as demonstrated on the screenshot below.

Virtual keyboard

I case you want to use a virtual keyboard, consider matchbox-keyboard.

The custom ebuild with the lastest version of the program is available here: matchbox-keyboard-999999.ebuild.
I use a custom keyboard layout. which is displayed on the screenshot below. The layout config file is here: keyboard.xml.
This keyboard works best with special settings of windows manager. In case you use OpenBox I recommend the following settings:

<applications>
  <application class="matchbox-keyboard">
    <decor>yes</decor>
    <layer>above</layer>
    <position>
      <x>center</x>
      <y>-0%</y>
    </position>
    <size>
      <height>30%</height>
      <width>100%</width>
    </size>
    <skip_pager>no</skip_pager>
    <skip_taskbar>no</skip_taskbar>
  </application>
</applications>

A desktop panel is very useful when the hardware keyboard is hidded. For example, it can be used to toggle the virtual keyboard. It looks like the device does not include a sensor to detect that the device is converted into tablet mode (please let me know if I’m wrong). Therefore I configured the autorotation script to launch the desktop panel (I prefer lxpanel) when the device is rotated. See the Accelerometer section for details.

Here is my config file for lxpanel. And here is the script I use to toggle the virtual keyboard: toggle_keyboard.sh.

Video

Kernel

The native orientation of the integrated display is portrait. Therefore the framebuffer console needs to be rotated. In order to configure correct orientation, add ‘fbcon=rotate:3’ to the kernel command line:

    CONFIG_CMDLINE="root=/dev/nvme0n1p5 fbcon=rotate:1 video=DSI-1:panel_orientation=right_side_up quiet i915.enable_guc=3"

X11 configuration

The VIDEO_CARDS variable should be set to ‘intel’. The global USE should include ‘dri’, see make.conf as example.

The modesetting driver (which is built into xorg-server) works fine, therefore it’s safe to get rid of the old xf86-video-intel driver. Down below you can see xorg.conf.d files for the UHD graphics.

30device.conf

    Section "Device"
      Identifier    "Intel Graphics"
      Driver        "modesetting"
    EndSection

40monitor.conf

    Section "Monitor"
      Identifier    "DSI-1"
      Option        "Rotate"                 "right"
      Option        "Primary"                "true"
    EndSection

    Section "Monitor"
      Identifier    "HDMI1"
      Option        "Disable"                "true"
    EndSection

    Section "Monitor"
      Identifier    "DP-1"
      Option        "Disable"                "true"
    EndSection

    Section "ServerFlags"
      Option "StandbyTime" "5"
    EndSection

DPI & scaling

It’s very easy to set correct DPI for the built-in display. Just add the following line to your ~/.Xdefaults:

    Xft.dpi: 144

However, this option will affect all displays connected to the device. If you use an external display, you may want to set different DPI.
One way to solve this issue is to use xrandr with the --scale option, for example:

    xrandr --output DSI-1 --scale 0.666667x0.666667

However, this will make the image a bit blurry. Please let me know if there is a way to set different DPI without blurring the image.

Here is a nice wrapup of the current X Server capabilities of handling mixed DPI: Mixed DPI and the X Window System.

Backlight

xbacklight currently does not work with the modesetting driver issue #47. The project acpilight provides a xbacklight drop in replacement which addresses the issue. In Gentoo this tool is provided by sys-power/acpilight.

Normally, users are prohibited to alter files in the sys filesystem. It’s advisable (and recommended) to setup an "udev" rule to allow users in the "video" group to set the display brightness. To do so, place a file in /etc/udev/rules.d/90-backlight.rules containing:

    SUBSYSTEM=="backlight", ACTION=="add", \
      RUN+="/bin/chgrp video /sys/class/backlight/%k/brightness", \
      RUN+="/bin/chmod g+w /sys/class/backlight/%k/brightness"

to setup the relevant permissions at boot time. These rules are very conservative: only the display brightness can be controlled, and nothing else. Do not set suid permissions on xbacklight.

HDMI output

HDMI output is supported by intel driver. You can use video-out.sh utility to toggle the HDMI output (via xrandr). The utility installs the external screen to the right of built-in screen. See the source code of video-out.sh for details.

3D acceleration

There are two available drivers: xf86-video-intel (obsolete driver) and the modesetting driver built into xorg-server (recommended).
The first one is significantly faster. glxgears shows approximately 5000 FPS using xf86-video-intel vs 3800 FPS using the modesetting driver.
However, xf86-video-intel is not recommeded by Gentoo commutiny, because this driver is obsolete and is no longer maintained by Intel. If you decide to use xf86-video-intel, you will need to update the X11 output name in xorg configuration files and the scripts like video-out.sh. xf86-video-intel provides eDP1, DP1, etc., while the modesetting drivers provides eDP-1, DP-1, etc. for the same outputs.

DRI works fine with default parameters.

The current modesetting driver from xf86-video-intel-1.20.11 with mesa-20.3.5 supports OpenGL-4.6. See glxinfo for details.

Video decoding acceleration

Intel UHD Graphics Xe G4 is able to decode a wide range of multimedia codecs [4]. The config parameters below describe how to enable hardware decoding via VA-API.

The global USE should include ‘vaapi’.

Custom USE flags:

    x11-libs/libva drm utils
    media-video/libva-utils drm vainfo
    x11-libs/libva-intel-media-driver set-as-default

Unmask the following packages:

    x11-libs/libva ~amd64
    x11-libs/libva-intel-driver ~amd64
    media-video/libva-utils ~amd64

Besides libva, you need a media player, which supports VA-API. You can use ‘mpv’, which does the job fine (except 4k ,see detail below). In this case, add the following config parameters to your mpv.conf

    vo=vaapi
    hwdec=vaapi-copy

You can check if hardware is configured properly by analyzing mpv output:

    Resuming playback. This behavior can be disabled with --no-resume-playback.
     (+) Video --vid=1 (*) (h264 1920x804 24.000fps)
     (+) Audio --aid=1 --alang=rus (*) (dts 6ch 48000Hz)
    Using hardware decoding (vaapi-copy).                         <<<--- THIS
    AO: [alsa] 48000Hz stereo 2ch float
    VO: [gpu] 1920x804 nv12
    AV: 00:00:24 / 02:00:38 (0%) A-V:  0.000
    Saving state.

or by viewing output of vainfo.

See also Components and Features of Intel(R) Media Driver for VAAPI.

Hardware decoding support allows the GPD Pocket 3 to play 4K 60fps video perfectly smoothly. For playback, users have a choice of several media players available. At minimum, the mpv and vlc players have been tested and successfully play 4K video.

Accelerometer

GPD Pocket 3 has a built-in accelerometer Memsic MXC4005XC. It can be used to change screen orientation automatically. If you are interested - read this section.

First of all, you need to install custom ebuild iio-sensor-proxy-2.0.ebuild, which provides iio-sensor-proxy daemon with optional systemd dependency.
Download the content of iio-sensor-proxy to /usr/local/portage/sys-apps/iio-sensor-proxy and install the package:

    cd /usr/local/portage/sys-apps/iio-sensor-proxy
    ebuild iio-sensor-proxy-2.0.ebuild digest
    emerge -av iio-sensor-proxy

Add iio-sensor-proxy to the default run level:

    rc-update add iio-sensor-proxy default

Download autorotate.sh to /usr/local/bin and setup the relevant permissions:

    chmod a+x /usr/local/bin/autorotate.sh

autorotate.sh is a small and dirty daemon written in Bash. You need to make it start when X11 session starts. If you use openbox WM, just add the following line to your ~/.config/openbox/autostart.sh:

    /usr/local/bin/autorotate.sh &

That's it. Restart X11 session and your screen, touchscreen and digitizer orientation will adjust automatically with the device orientation.

Sound

Supported by CONFIG_SND_HDA_INTEL. I recommend to compile alsa-lib with all plugins (ALSA_PCM_PLUGINS, see make.conf as example).

In general ALSA supports the Realtek ALC269 quite well: both internal speaker and mic work fine as well as headphones jacks. ALSA mutes the speaker when headphones jack is used.

Networking

Ethernet

Supported by CONFIG_R8169. Requires firmware rtl_nic/rtl8125b-2.fw. Configured via default gentoo net config. Here is an example of eth0 definition with static IP. See Gentoo Network Configuration for details.

ethtool may be used to detect whether ethernet cable is plugged or not.

WiFi

WiFi is also supported by kernel (CONFIG_IWLWIFI). The driver requires binary firmware iwlwifi-ty-a0-gf-a0-89.ucode' and 'iwlwifi-ty-a0-gf-a0.pnvm.

WiFi connection can be configured via wpa_supplicant. See Wireless Networking for details.

The iwl driver supports power management, which is enabled by default. You can check whether power management is turned on using iwconfig:

    wlan0     IEEE 802.11  ESSID:"vm"  
              Mode:Managed  Frequency:2.462 GHz  Access Point: 46:73:9D:8F:76:BA   
              Bit Rate=144.4 Mb/s   Tx-Power=22 dBm   
              Retry short limit:7   RTS thr:off   Fragment thr:off
              Power Management:on
              Link Quality=70/70  Signal level=-38 dBm  
              Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
              Tx excessive retries:0  Invalid misc:962   Missed beacon:0

This file provides the temperature of the WiFi chip:

    /sys/devices/virtual/thermal/thermal_zone1/temp

Bluetooth

Bluetooth should be supported by modern Linux kernels. However, we did not have the need to configure Bluetooth, so this functionality remains untested for now.
Nevertheless, if you want to configure it, the driver requires binary firmware intel/ibt-0041-0041.sfi. Enable the use of this firmware in the kernel (parameter CONFIG_EXTRA_FIRMWARE).

rfkill

GPD Pocket 3 does not have a hardware rfkill switch. But you can configure software button using the rfkill tool. See toggle_wireless.sh as example. The script toggles wireless connectivity for Wi-Fi, Bluetooth, and other radio devices.

ACPI

In order to handle ACPI events, you need to install the ACPI daemon and add it to the boot runlevel:

emerge -av acpid
rc-update add acpid boot

All ACPI events are configured in the default.sh. Here is a short description of the ACPI events handled by default.sh:

  • Power - Generates keycode 192 (XF86Launch0) via acpi_fakekey, which shows the system info window. You can uncomment one line in the script to turns the system off instead.
  • Lid - Suspends to RAM if the display is not turned off via locked via dpms.sh. See 00dpms for details.
  • AC plug in/out - Switches cpufreq governor to performance when AC gets connected and to powersave when AC gets disconnected.

Besides the events handled in default.sh, acpid also catches the following ones:

  • video/brightnessdown BRTDN 00000087 00000000 K
  • video/brightnessup BRTUP 00000086 00000000 K
  • button/volumedown VOLDN 00000080 00000000 K
  • button/volumeup VOLUP 00000080 00000000 K
  • button/mute MUTE 00000080 00000000 K
  • jack/headphone HEADPHONE plug
  • jack/microphone MICROPHONE plug
  • jack/microphone MICROPHONE unplug
  • jack/headphone HEADPHONE unplug

All multimedia keys generate scancode and are described in the Input section. However, you can write a handler for the respective keyboard events. The main advantage of ACPI hot keys is that they're not dependent on WM (which handles multimedia keys) and work even in console and SDL programs.

You can use the acpi command to monitor the AC and battery information:

    #acpi -abit
    Battery 0: Charging, 85%, 73:00:00 until charged
    Battery 0: design capacity 3947 mAh, last full capacity 3478 mAh = 88%
    Adapter 0: on-line

ACPI does not provide any information about Fan and Cooling. It looks like the Fan can only be controlled by hardware.

CPU frequency scaling

Supported by CONFIG_X86_INTEL_PSTATE The default governor can be selected via options CONFIG_CPU_FREQ_DEFAULT_GOV_*.

Install sys-power/cpupower packages in order to monitor or control frequency scaling:

    $ cpupower frequency-info 
    analyzing CPU 0:
      driver: intel_pstate
      CPUs which run at the same hardware frequency: 0
      CPUs which need to have their frequency coordinated by software: 0
      maximum transition latency:  Cannot determine or is not supported.
      hardware limits: 400 MHz - 3.70 GHz
      available cpufreq governors: performance powersave
      current policy: frequency should be within 400 MHz and 3.70 GHz.
                      The governor "performance" may decide which speed to use
                      within this range.
      current CPU frequency: Unable to call hardware
      current CPU frequency: 1.48 GHz (asserted by call to kernel)
      boost state support:
        Supported: yes
        Active: yes

Suspending

Suspend-to-RAM

Suspend-to-RAM (aka sleep or ACPI S3 state) is supported by CONFIG_SUSPEND and works flawlessly.

Suspend-to-disk

In order to use native Linux hibernator, you need to enable CONFIG_HIBERNATION and specify your swap partition either in CONFIG_PM_STD_PARTITION or in the resume kernel parameter.

ACPI subsystem in GPD Pocket 3 does not generate an event when battery capacity changes. Therefore in order to perform automatic hibernation when battery capacity goes beyond critical level, we need a daemon monitoring the battery capacity level. One simple way to implement this is to use a cron daemon with a simple script checking the battery level.

You can use low_battery_handler.sh to check the battery level and hibernate when the battery level is less than or equal to 3%.

There are various cron implementations available in the Gentoo repository, which slightly differ in configuration. In case of dcron, do the following as root.

    emerge -av dcron
    rc-update add dcron boot
    crontab -e

Add the following line to opened cron configuration file:

    * * * * * /usr/local/bin/low_battery_handler.sh

That's it. Your Pocket 3 should now hibernate automatically on low battery.

Power Management Utilities

You can use pm-utils package (the power management utilities) in order to run user supplied scripts on suspend and resume. Additionally, you may be interested in the following:

Important Note: Although pm-utils is officially considered deprecated and hasn't been developed since 2013, it remains a practical tool for users who need a simple and working sleep/wake management system without unnecessary complexity. Major distributions (Arch, Debian, Gentoo) are migrating to elogind/systemd-logind, but pm-utils continues to function successfully on systems with traditional init systems.

Why pm-utils nonetheless: Unlike elogind, which requires proper configuration of D-Bus, polkit, seat management and can conflict with other power management daemons, pm-utils presents a simple model with clear hooks in /etc/pm/sleep.d/ and works "out of the box" with minimal configuration. This is especially relevant for OpenRC users or other alternative init systems, where elogind integration may require additional debugging.

Recommendation: If pm-utils solves power management tasks without issues, there's no need to migrate to elogind just for the sake of being "modern." However, it's worth considering that new desktop environments and applications may gradually lose compatibility with pm-utils, expecting the presence of the org.freedesktop.login1 D-Bus interface.

Here you can find a modern ebuild for building pm-utils along with patches containing fixes and minor improvements.

Web camera

To support the camera, the following kernel options are required: CONFIG_USB_VIDEO_CLASS, CONFIG_MEDIA_CAMERA_SUPPORT, CONFIG_VIDEO_V4L2_I2C, CONFIG_VIDEOBUF2_V4L2.
The camera functionality can be tested using the following ffmpeg command:

    ffmpeg -f video4linux2 -i /dev/v4l/by-id/usb-Alcor_Micro__Corp._USB_2.0_Camera-video-index0 -input_format mjpeg -framerate 30 -vf "format=yuv420p" -f xv display

Known issues

  1. Fingerprint reader is not supported.
  2. The kernel shows the following ACPI error messages during bootup:

    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.SEN4], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC._QF1 due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.SEN4], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC._QF1 due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.SEN4], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC._QF1 due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.SEN4], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC._QF1 due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.SEN4], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC._QF1 due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.SEN4], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC._QF1 due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.SEN4], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC._QF1 due to previous error (AE_NOT_FOUND) (20240827/psparse-529)
    ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.SEN4], AE_NOT_FOUND (20240827/psargs-332)
    ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC._QF1 due to previous error (AE_NOT_FOUND) (20240827/psparse-529)

These ACPI BIOS errors occur during Linux boot due to missing ACPI object references in the laptop's firmware tables. The errors indicate USB controller issues with _SB.UBTC.RUCC symbols and embedded controller problems with _SB.PC00.LPCB.HEC.SEN4 thermal sensor definitions.

Root Cause: The BIOS firmware contains incomplete ACPI table definitions where USB controllers and embedded controllers reference non-existent objects. This is a common manufacturer defect where ACPI tables violate standards but don't affect Windows functionality, so vendors don't fix them.

Impact Assessment: These errors are typically cosmetic and don't affect laptop functionality. Such ACPI errors rarely cause practical problems in the industry. In this author's practical experience, no operational consequences have been observed - USB ports work normally, hibernation functions properly, and thermal management operates correctly despite the error messages appearing consistently in kernel logs.

The Linux kernel handles missing ACPI objects gracefully by falling back to alternative enumeration methods, making these particular AE_NOT_FOUND errors largely harmless in real-world usage scenarios.

Benchmarks

Here are few relevant benchmarks:

Test conditions Results
Bootup (from EFI boot menu to X11 WM) 11 sec
Suspend-to-disk aka hibernate (linux-6.15.4, only X11 WM, no apps running) 8 sec
Resume from suspend-to-disk (from EFI boot menu, linux-6.15.4) 9 sec
Suspend-to-RAM (linux-6.15.4) 3 sec
Resume from suspend-to-RAM (linux-6.15.4) 2 sec
SSD read speed (WD Black SN850X, hdparm) 2600 MB/s
SSD write speed (WD Black SN850X, dd, bs=1M) 3400 MB/s
WiFi download speed (with AP based on Atheros QCA988x) ~450 Mbit/s
WiFi upload speed (with AP based on Atheros QCA988x) ~90 Mbit/s
Quake 3 (1920x1200, high quality, xorg-server-21.1.18, mesa-25.1.7) 137 fps
glxgears (6.15.4, xorg-server-21.1.18, mesa-25.1.7) 4000 fps
Idle consumption (minimal brightness, no wireless) 3.4 W

History of changes

Sept 29 2025
First public release.

NoName P8 – a remarkable UMPC

The P8 is a modern 8-inch UMPC from an unknown manufacturer. It has a swivel hinge display and is convertible into a tablet. The device is sold on Aliexpress under a variety of little-known brands. The device is notable for the fact that at its price of $250, it offers an interesting specification. There are no completely failed characteristics. For specifications, see the item description.

In terms of build quality, the device is, of course, inferior to the flagship devices from One-NetbooK. But in general, the quality is quite good and no worse than, for example, the Fujitsu U810. See the photos in the gallery below.

And in terms of performance, the P8 even surpasses some competitors, which are many times more expensive. For details, see Benchmarking NoName P8.
PassMark Performance Test results

This price-performance ratio makes the NoName P8 stand out from the modern line of UMPC devices.

Kohjinsha SR – a UMPC with internal DVD writer

When you think of removable storage media for handheld computers, something like the items presented in the previous blog post usually comes to mind: Removable storage and RAM for handheld computers.
But there is one UMPC that is notably different in this regard – this is the Kohjinsha SR (SR8KP06A). This 7-inch handheld is equipped with a CD/DVD writer.
Specifications of the device are available here.