Handbook

Wi-Fi
Desktop hotkeys
Audio
Battery
Keymap
SSH
Updates
Kernel rollback
Kernel command line
Display timings

Wi-Fi

The built-in Wi-Fi adapter is enabled on boot. You can configure your network using nmtui in the terminal (on the desktop, this is also found in the menu under Settings > NetworkManager). If your netbook shipped with the older 802.11g adapter rather than the 802.11n variant, you may need to ensure your router allows legacy 802.11g clients.

Desktop hotkeys

The desktop profile ships with a few system-wide hotkeys. These can be overridden per-user by editing ~/.icewm/keys:

Keys	Action
Super+Up / Super+Down	Display brightness
Super+= / Super+-	Volume
Alt+Ctrl+T	Terminal
Alt+Ctrl+B	Web browser

On these netbooks, the Super key corresponds to the key printed with a Zzz sleep icon, located exactly where the Windows key normally sits. If a window opens off-screen, hold Alt and drag to move it.

Audio

Run alsamixer in the terminal for the full set of audio controls. The available controls vary by codec.

To make a USB sound card the default audio device, create ~/.asoundrc with the two lines below, using the card number shown by aplay -l.

defaults.pcm.card 1
defaults.ctl.card 1

The standard profile does not include audio utilities by default. To add them, run sudo apt install alsa-utils.

Battery

These netbooks measure the battery indirectly, by timing a simple RC circuit whose scale varies from unit to unit, so the driver calibrates itself against the one fixed voltage reference the board provides: the low-battery alarm. On a fresh install, only the charging state is reported. The charge percentage appears once the battery has drained down to the alarm for the first time, and works normally thereafter.

While plugged in, the charger's voltage masks the battery's own, so the percentage cannot update. Instead, it keeps the last reading taken on battery, if any, and shows full once charging completes. Calibration happens entirely on its own, repeats at every later alarm, and persists across reboots and updates.

Keymap

The keymap chosen during setup applies to both the console and the desktop. Layouts that cannot type Latin keep us alongside, switched with Alt+Shift. To change it later, run sudo dpkg-reconfigure keyboard-configuration and reboot.

SSH

Dropbear provides the SSH server, with host keys uniquely generated on first boot. Because Dropbear lacks SFTP support, file transfers must use SCP (scp -O on newer OpenSSH clients, which default to SFTP) or the FISH protocol.

Updates

Every image is preconfigured with the signed WMT OS APT repository at apt.wmt-os.org, pinned above Debian. Upgrading works the same as on any Debian-based system:

sudo apt update && sudo apt upgrade

When a new kernel installs, it builds its U-Boot files automatically and takes effect on the next reboot, keeping the previous kernel safely as a rollback.

Kernel rollback

If a kernel update causes issues, the boot partition carries a script to revert to the previous kernel:

Windows or Windows CE: Run rollback.cmd.
Linux or macOS: Run sh /path/to/rollback.sh.

The script displays the current and previous kernels and prompts you to switch between them. Re-run it to switch back.

Kernel command line

Extra arguments can be passed to the kernel at boot by setting EXTRA_CMDLINE in /etc/default/wmt-boot:

EXTRA_CMDLINE="loglevel=7"

Run sudo wmt-deploy-boot to apply the change, which takes effect on the next reboot. The arguments are appended to the built-in boot arguments and persist across kernel updates. Rolling back to the previous kernel also restores its original arguments.

Display timings

The kernel reads the panel timings from the bootloader's lcdparam variable automatically. They can be overridden by passing wmt_panel.lcd on the kernel command line:

EXTRA_CMDLINE="wmt_panel.lcd=1,30000,8,800,480,48,40,40,3,29,13"

The fields are the version (always 1), pixel clock in kHz, color depth (unused), width, height, horizontal sync width, back porch, and front porch, then the vertical sync width, back porch, and front porch.