UEFI

Overview

The UEFI display/input driver offers support for using LVGL to create UIs in UEFI environments.

Prerequisites

You need the following UEFI protocols available:

  • EFI_LOADED_IMAGE_PROTOCOL_GUID: for file system support (used to determine the file system used to load the application)

  • EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID: for file system support

  • EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL_GUID: for keyboard support

  • EFI_SIMPLE_POINTER_PROTOCOL_GUID: for mouse support

  • EFI_ABSOLUTE_POINTER_PROTOCOL_GUID: for touch support

  • EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID: for drawing

  • EFI_EDID_ACTIVE_PROTOCOL_GUID: for drawing (optional)

Configuration

  1. Enable the UEFI driver support in lv_conf.h:

#define LV_USE_UEFI  1

  • Enable the memory core functions, which are wrappers around AllocatePool and FreePool (using memory of type EfiBootServicesData) if you do not wan't to use your own implementations

#define LV_UEFI_USE_MEMORY_SERVICES  1

  1. Enable file system support for the volume the application was loaded from (defaults to drive letter E):

#define LV_USE_FS_UEFI  1

  1. Include UEFI type definitions. There are predefined includes for EDK2 and GNU-EFI:

#define LV_USE_UEFI_INCLUDE <lvgl/src/drivers/uefi/lv_uefi_edk2.h>
// or
#define LV_USE_UEFI_INCLUDE <lvgl/src/drivers/uefi/lv_uefi_gnu_efi.h>

Usage

A minimal example:

#include "lvgl/lvgl.h"
#include "lvgl/examples/lv_examples.h"
#include "lvgl/demos/lv_demos.h"

EFI_STATUS EFIAPI EfiMain(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
{
    lv_uefi_init(ImageHandle, SystemTable);
    lv_init();

    if (!lv_is_initialized()) return EFI_NOT_READY;

    EFI_HANDLE handle = lv_uefi_display_get_active();
    if (!handle) handle = lv_uefi_display_get_any();
    if (!handle) {
        lv_deinit();
        return EFI_UNSUPPORTED;
    }

    lv_display_t *display = lv_uefi_display_create(handle);
    lv_display_set_default(display);

    lv_group_t *group = lv_group_create();
    lv_group_set_default(group);

    lv_obj_t *cursor = lv_image_create(lv_layer_top());
    lv_image_set_src(cursor, "E:cursor.png");

    lv_indev_t *indev;

    indev = lv_uefi_simple_text_input_indev_create();
    lv_indev_set_group(indev, group);
    lv_uefi_simple_text_input_indev_add_all(indev);

    indev = lv_uefi_simple_pointer_indev_create(NULL);
    lv_uefi_simple_pointer_indev_add_all(indev);
    lv_indev_set_cursor(indev, cursor);

    indev = lv_uefi_absolute_pointer_indev_create(NULL);
    lv_uefi_absolute_pointer_indev_add_all(indev);

    lv_demo_widgets();

    size_t counter = 0;
    while (counter < 10000) {
        counter++;
        gBS->Stall(1000);
        lv_tick_inc(1);
        lv_timer_handler();
    }

    return EFI_SUCCESS;
}