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 static const efi_guid_t loaded_image_guid = LOADED_IMAGE_GUID;
  17
  18 /*
  19  * Entry point of the EFI application.
  20  *
  21  * @handle      handle of the loaded image
  22  * @systable    system table
  23  * @return      status code
  24  */
  25 efi_status_t EFIAPI efi_main(efi_handle_t handle,
  26                              struct efi_system_table *systable)
  27 {
  28         struct efi_simple_text_output_protocol *con_out = systable->con_out;
  29         struct efi_boot_services *boottime = systable->boottime;
  30         struct efi_loaded_image *loaded_image;
  31         efi_status_t ret;
  32
  33         con_out->output_string(con_out, L"Hello, world!\n");
  34
  35         /* Get the loaded image protocol */
  36         ret = boottime->handle_protocol(handle, &loaded_image_guid,
  37                                         (void **)&loaded_image);
  38         if (ret != EFI_SUCCESS) {
  39                 con_out->output_string(con_out,
  40                                        L"Cannot open loaded image protocol\n");
  41                 goto out;
  42         }
  43         /* Output the load options */
  44         con_out->output_string(con_out, L"Load options: ");
  45         if (loaded_image->load_options_size && loaded_image->load_options)
  46                 con_out->output_string(con_out,
  47                                        (u16 *)loaded_image->load_options);
  48         else
  49                 con_out->output_string(con_out, L"<none>");
  50         con_out->output_string(con_out, L"\n");
  51
  52 out:
  53         boottime->exit(handle, ret, 0, NULL);
  54
  55         /* We should never arrive here */
  56         return ret;
  57 }