lib/efi_loader/helloworld.c

   1 /*
   2  * EFI hello world
   3  *
   4  * Copyright (c) 2016 Google, Inc
   5  * Written by Simon Glass <sjg@chromium.org>
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  *
   9  * This program demonstrates calling a boottime service.
  10  * It writes a greeting and the load options to the console.
  11  */
  12
  13 #include <common.h>
  14 #include <efi_api.h>
  15
  16 /*
  17  * Entry point of the EFI application.
  18  *
  19  * @handle      handle of the loaded image
  20  * @systable    system table
  21  * @return      status code
  22  */
  23 efi_status_t EFIAPI efi_main(efi_handle_t handle,
  24                              struct efi_system_table *systable)
  25 {
  26         struct efi_simple_text_output_protocol *con_out = systable->con_out;
  27         struct efi_boot_services *boottime = systable->boottime;
  28         struct efi_loaded_image *loaded_image;
  29         const efi_guid_t loaded_image_guid = LOADED_IMAGE_GUID;
  30         efi_status_t ret;
  31
  32         con_out->output_string(con_out, L"Hello, world!\n");
  33
  34         /* Get the loaded image protocol */
  35         ret = boottime->handle_protocol(handle, &loaded_image_guid,
  36                                         (void **)&loaded_image);
  37         if (ret != EFI_SUCCESS) {
  38                 con_out->output_string(con_out,
  39                                        L"Cannot open loaded image protocol\n");
  40                 goto out;
  41         }
  42         /* Output the load options */
  43         con_out->output_string(con_out, L"Load options: ");
  44         if (loaded_image->load_options_size && loaded_image->load_options)
  45                 con_out->output_string(con_out,
  46                                        (u16 *)loaded_image->load_options);
  47         else
  48                 con_out->output_string(con_out, L"<none>");
  49         con_out->output_string(con_out, L"\n");
  50
  51 out:
  52         boottime->exit(handle, ret, 0, NULL);
  53
  54         /* We should never arrive here */
  55         return ret;
  56 }