Seamless Switches from Clone Mode to VEXT Mode

Under normal circumstance, after system boot up and starting X, you may see programs or client applications loading information on the screen before the home screen is fully up and running. To make the program/client application loading screen invisible, Intel^® EMGD provides an option for you to retain the boot up splash screen and switch to the home screen through an escape function call when the home screen is ready.

This feature is implemented for a specific usage model only, where the system is expected to boot up in Clone mode with a splash/logo screen and continues to be shown on the display until the X-Window/Home screen is fully up and running in VEXT mode. The transition from Clone to VEXT display mode will be handled seamlessly.

To enable this feature, use CED to generate the EFI and the Linux driver with appropriate attributes set.

1. Configure and generate EFI with Clone mode configuration.

2. Configure and generate the Linux driver installation package with VEXT mode and seamless mode flag set.

a. For VEXT mode: configure the CED->Chipset Configuration Page -> Display Configuration Mode= Vertical Extended. If you like to edit the xorg.conf and user_config.c files directly, ensure that you specify the following attributes in the files:

• xorg.conf file: Option “ALL/1/General/DisplayConfig” “2”

• user_config.c file: DisplayConfig = 5 in the DRM configuration array

b. Seamless mode from EFI GOP to DRM: configure the CED-> EFI GOP Configuration Page -> Enable Seamless Mode = Checked (1). This configuration applies to the user_config.c file. If you like to edit the file directly, ensure that you specify the following attribute in the file:

user_config.c file: set the Seamless = 1 in the parameter configuration array

c. Seamless mode from DRM to X-Window: configure the CED-> EMGD Package Page->Linux Option Page -> Enable Seamless Mode Set for DRM->X transition = checked (1). This configuration applies to the xorg.conf file. If you like to edit the file directly, ensure that you specify the following attribute in the file:

xorg.conf file: option “ALL/1/General/SeamlessModeset” “1”

3. Ensure the resolution configured for clone mode and VEXT primary display are of the same resolution.

Seamless switches from Clone mode to VEXT mode work in such a way that EFI boots up the system in Clone mode and the DRM driver will check the configuration mentioned above in steps 1-3. If the requirement is fulfilled, the display plane register will be locked and the framebuffer content for both screens in Clone mode will be retained. The kernel mode driver will keep deferring plane register updates (for VEXT mode) until the client application sends an ESCAPE API to end it.

To unlock the display plane register, the client application sends ESCAPE API INTEL_ESCAPE_SHOW_DESKTOP to the X11 driver. After the plane registers are unlocked, the registers are updated and enable X rendered screens to display in VEXT mode.

Note: This feature is applicable only for system configurations with a combination of EFI with Clone mode and the graphics driver with VEXT mode configurations.