How I got my Acer C720P Chromebook with SeaBios setup with Debian 13

c720p_debian13.md

downloaded debian-13.4.0-amd64-netinst.iso and placed onto a USB stick with:

sudo dd if=debian-13.0.0-amd64-netinst.iso of=/dev/sdX bs=4M status=progress oflag=sync

Installed:

• LXQt
• minimal system (no extra desktop environments, no SSH Server)

---

To get the keyboard top row shortcuts setup

Install required packages

.

To get the keyboard top row shortcuts setup

sudo apt update
sudo apt install xbindkeys xdotool brightnessctl

Shell script for handling brightness and volume with user-defined increment

mkdir -p ~/bin
cat > ~/bin/c720-toprow.sh <<'EOF'
#!/bin/bash
set -euo pipefail

STEP_BRIGHTNESS="${STEP_BRIGHTNESS:-1%}"
STEP_VOLUME="${STEP_VOLUME:-5%}"

case "${1:-}" in
  brightness_down)
    brightnessctl set "${STEP_BRIGHTNESS}-"
    ;;
  brightness_up)
    brightnessctl set "${STEP_BRIGHTNESS}+"
    ;;
  mute)
    pactl set-sink-mute @DEFAULT_SINK@ toggle
    ;;
  volume_down)
    pactl set-sink-volume @DEFAULT_SINK@ "-${STEP_VOLUME}"
    ;;
  volume_up)
    pactl set-sink-volume @DEFAULT_SINK@ "+${STEP_VOLUME}"
    ;;
esac
EOF

chmod +x ~/bin/c720-toprow.sh

xbindkeys to map keypresses to shell script

cat > ~/.xbindkeysrc <<'EOF'
# C720 Chromebook top row bindings
"~/bin/c720-toprow.sh brightness_down"
  F6

"~/bin/c720-toprow.sh brightness_up"
  F7

"~/bin/c720-toprow.sh mute"
  F8

"~/bin/c720-toprow.sh volume_down"
  F9

"~/bin/c720-toprow.sh volume_up"
  F10
EOF

auto-start xbindkeys

mkdir -p ~/.config/autostart
cat > ~/.config/autostart/xbindkeys.desktop <<'EOF'
[Desktop Entry]
Type=Application
Name=xbindkeys
Exec=xbindkeys
EOF

Xmodmap for back/forward/refresh keys, plus Search/Super + arrows for home/end/pgup/pgdown

cat > ~/.Xmodmap <<'EOF'
keycode 67 = XF86Back
keycode 68 = XF86Forward
keycode 69 = XF86Refresh

remove mod4 = Super_L
keycode 133 = Mode_switch
add mod5 = Mode_switch

keycode 111 = Up Up Prior Prior
keycode 113 = Left Left Home Home
keycode 114 = Right Right End End
keycode 116 = Down Down Next Next
EOF

auto-start Xmodmap

cat > ~/.config/autostart/xmodmap.desktop <<'EOF'
[Desktop Entry]
Type=Application
Name=Load Xmodmap
Exec=/usr/bin/xmodmap /home/$USER/.Xmodmap
EOF

If $USER does not expand there in LXQt on your system, use your real username instead.

Trackpad

tap-to-click

1. Open Preferences → Keyboard and Mouse
2. Go to Mouse and Touchpad tab
3. Enable: Tap to click
4. Apply

right-click

it seems the hardware only supports two-finger right-click.

bottom-right click is not possible

• This is just for documentation.

user@debian-c720p:~$ sudo apt install xinput

user@debian-c720p:~$ xinput list|grep -i pointer
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Cypress APA Trackpad (cyapa)              id=11   [slave  pointer  (2)]

user@debian-c720p:~$ xinput list-props "Cypress APA Trackpad (cyapa)"|grep "Click Method Enabled"
        libinput Click Method Enabled (314):    0, 1
        libinput Click Method Enabled Default (315):    0, 1

xinput set-prop "Cypress APA Trackpad (cyapa)" "libinput Click Method Enabled" 1 0 is ignored, so this supposedly means only two-finger right-click is possible.

RAM usage improvements

zram - RAM compression

1. Install zram-tools sudo apt install zram-tools

2. Configure for your hardware sudo nano /etc/default/zramswap

File should only contain (other than comments)

ALGO=lz4
PERCENT=100
PRIORITY=100

3. Restart zram sudo systemctl restart zramswap

4. Lower disk swap usage (Keep disk swap but make it rarely used):

echo 'vm.swappiness=10' | sudo tee /etc/sysctl.d/99-swappiness.conf
sudo sysctl -p /etc/sysctl.d/99-swappiness.conf

High-impact Firefox fixes (you need these)

In about:config:

1. Biggest win: reduce process count

dom.ipc.processCount = 2

2. Disable site isolation (huge on low RAM)

fission.autostart = false

3. Disable WebRender (your GPU is old)

layers.acceleration.force-enabled = false
gfx.webrender.all = false

4. Reduce browser history (previous page) cache (used for fast back/forward)

browser.sessionhistory.max_total_viewers = 6

5. Disable accessibility (screen readers and other assistive-tech)

accessibility.force_disabled = 1

Install uBlock Origin extension (mandatory)

Optional: trim background services (you have some bloat)

sudo systemctl disable --now ModemManager
sudo systemctl disable --now cups
sudo systemctl disable --now speech-dispatcher

---

Final Behavior

Top Row Keys

• F1 → Back
• F2 → Forward
• F3 → Refresh
• F6/F7 → Brightness (1% steps by default)
• F8/F9/F10 → Audio controls

Search Key (Chromebook key)

• Remapped to Mode_switch

Navigation (Chromebook-style)

• Search + Left → Home
• Search + Right → End
• Search + Up → Page Up
• Search + Down → Page Down

Touchpad

tap-to-click is enabled, two-finger right-click was enabled by default

Notes

• STEP_BRIGHTNESS and STEP_VOLUME can be adjusted in the script
• Using Mode_switch avoids conflicts with Firefox (Alt+Left = Back)
• xbindkeys is only used for brightness/audio — navigation handled at XKB level