src/boot/efi/graphics.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright © 2013 Intel Corporation
 *   Authored by Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
 */

#include <efi.h>
#include <efilib.h>

#include "graphics.h"
#include "util.h"

#define EFI_CONSOLE_CONTROL_GUID \
        &(EFI_GUID) { 0xf42f7782, 0x12e, 0x4c12, { 0x99, 0x56, 0x49, 0xf9, 0x43, 0x4, 0xf7, 0x21 } }

EFI_STATUS graphics_mode(BOOLEAN on) {

        struct _EFI_CONSOLE_CONTROL_PROTOCOL;

        typedef enum {
                EfiConsoleControlScreenText,
                EfiConsoleControlScreenGraphics,
                EfiConsoleControlScreenMaxValue,
        } EFI_CONSOLE_CONTROL_SCREEN_MODE;

        typedef EFI_STATUS (EFIAPI *EFI_CONSOLE_CONTROL_PROTOCOL_GET_MODE)(
                struct _EFI_CONSOLE_CONTROL_PROTOCOL *This,
                EFI_CONSOLE_CONTROL_SCREEN_MODE *Mode,
                BOOLEAN *UgaExists,
                BOOLEAN *StdInLocked
        );

        typedef EFI_STATUS (EFIAPI *EFI_CONSOLE_CONTROL_PROTOCOL_SET_MODE)(
                struct _EFI_CONSOLE_CONTROL_PROTOCOL *This,
                EFI_CONSOLE_CONTROL_SCREEN_MODE Mode
        );

        typedef EFI_STATUS (EFIAPI *EFI_CONSOLE_CONTROL_PROTOCOL_LOCK_STD_IN)(
                struct _EFI_CONSOLE_CONTROL_PROTOCOL *This,
                CHAR16 *Password
        );

        typedef struct _EFI_CONSOLE_CONTROL_PROTOCOL {
                EFI_CONSOLE_CONTROL_PROTOCOL_GET_MODE GetMode;
                EFI_CONSOLE_CONTROL_PROTOCOL_SET_MODE SetMode;
                EFI_CONSOLE_CONTROL_PROTOCOL_LOCK_STD_IN LockStdIn;
        } EFI_CONSOLE_CONTROL_PROTOCOL;

        EFI_CONSOLE_CONTROL_PROTOCOL *ConsoleControl = NULL;
        EFI_CONSOLE_CONTROL_SCREEN_MODE new;
        EFI_CONSOLE_CONTROL_SCREEN_MODE current;
        BOOLEAN uga_exists;
        BOOLEAN stdin_locked;
        EFI_STATUS err;

        err = LibLocateProtocol(EFI_CONSOLE_CONTROL_GUID, (VOID **)&ConsoleControl);
        if (EFI_ERROR(err))
                /* console control protocol is nonstandard and might not exist. */
                return err == EFI_NOT_FOUND ? EFI_SUCCESS : err;

        /* check current mode */
        err = uefi_call_wrapper(ConsoleControl->GetMode, 4, ConsoleControl, &current, &uga_exists, &stdin_locked);
        if (EFI_ERROR(err))
                return err;

        /* do not touch the mode */
        new  = on ? EfiConsoleControlScreenGraphics : EfiConsoleControlScreenText;
        if (new == current)
                return EFI_SUCCESS;

        err = uefi_call_wrapper(ConsoleControl->SetMode, 2, ConsoleControl, new);

        /* some firmware enables the cursor when switching modes */
        uefi_call_wrapper(ST->ConOut->EnableCursor, 2, ST->ConOut, FALSE);

        return err;
}