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Native Display Mode Helper

MagicDesk Display Fixes is an independent, optional APK for firmware that exposes a monitor's complete DisplayPort timing list only to root. It is not a MagicDesk runtime dependency. Signed development builds are available from the rolling development prerelease.

The helper currently supports the Nubia display interface verified on the Z80 Ultra. It has no model allowlist. On each launch it checks for all required runtime evidence instead:

  • a wired Android external display is connected;
  • direct su access was granted by the user's superuser manager;
  • /sys/kernel/lcd_enhance/edid_modes is present and readable;
  • the node contains at least one valid advertised timing.

If any check fails, the helper changes nothing and reports the missing capability. It does not use or depend on Shizuku.

Operation

The launcher activity performs one bounded operation and then remains idle:

  1. Request direct root through su -c.
  2. Read and parse the firmware's advertised EDID timing list.
  3. Select the highest native resolution and its highest refresh rate, avoiding a cinema-aspect duplicate when an equivalent normal timing is present.
  4. Clear an old Android user-preferred mode for the connected display.
  5. Apply Nubia's normal display-refresh and HPD sequence.
  6. Wait until Android reports the requested timing in three consecutive observations.

The dimensions are never hardcoded and are never accepted from user input. The HPD node is restored to the connected state if the root command is interrupted after disconnecting it. No daemon, boot receiver, persistent root process, Shizuku binding, or Magisk module is installed.

The common EDID parser and native-mode selection policy live in the pure Java display-mode-core module. MagicDesk and the helper therefore cannot silently choose different native timings.

Use

  1. Connect the monitor or glasses while Android is already exposing a wired external display.
  2. Open MagicDesk Display Fixes and grant its one-time root request.
  3. Wait for Native mode applied or Native mode already active.
  4. In MagicDesk, leave Output mode at System / native, then start the external desktop normally.

Running the helper again is safe: it reports the mode as already active when the selected timing is already visible to Android. Disconnecting the display or rebooting may return ownership to the firmware, so the helper can be run again before a later MagicDesk session.

Build

./gradlew :display-fixes:assembleDebug

The APK is generated under display-fixes/build/outputs/apk/debug/. Normal CI builds and checks this module to prevent it from drifting. Pushes to main also publish the signed helper as DisplayFixes-development.apk. Tagged MagicDesk releases continue to publish only the main application unless a helper build is intentionally included.