git.sur5r.net Git - u-boot/blob - 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 static const efi_guid_t fdt_guid = EFI_FDT_GUID;
  18 static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID;
  19
  20 static int hw_memcmp(const void *buf1, const void *buf2, size_t length)
  21 {
  22         const u8 *pos1 = buf1;
  23         const u8 *pos2 = buf2;
  24
  25         for (; length; --length) {
  26                 if (*pos1 != *pos2)
  27                         return *pos1 - *pos2;
  28                 ++pos1;
  29                 ++pos2;
  30         }
  31         return 0;
  32 }
  33
  34 /*
  35  * Entry point of the EFI application.
  36  *
  37  * @handle      handle of the loaded image
  38  * @systable    system table
  39  * @return      status code
  40  */
  41 efi_status_t EFIAPI efi_main(efi_handle_t handle,
  42                              struct efi_system_table *systable)
  43 {
  44         struct efi_simple_text_output_protocol *con_out = systable->con_out;
  45         struct efi_boot_services *boottime = systable->boottime;
  46         struct efi_loaded_image *loaded_image;
  47         efi_status_t ret;
  48         efi_uintn_t i;
  49
  50         con_out->output_string(con_out, L"Hello, world!\n");
  51
  52         /* Get the loaded image protocol */
  53         ret = boottime->handle_protocol(handle, &loaded_image_guid,
  54                                         (void **)&loaded_image);
  55         if (ret != EFI_SUCCESS) {
  56                 con_out->output_string(con_out,
  57                                        L"Cannot open loaded image protocol\n");
  58                 goto out;
  59         }
  60         /* Find configuration tables */
  61         for (i = 0; i < systable->nr_tables; ++i) {
  62                 if (!hw_memcmp(&systable->tables[i].guid, &fdt_guid,
  63                                sizeof(efi_guid_t)))
  64                         con_out->output_string(con_out, L"Have device tree\n");
  65                 if (!hw_memcmp(&systable->tables[i].guid, &smbios_guid,
  66                                sizeof(efi_guid_t)))
  67                         con_out->output_string(con_out, L"Have SMBIOS table\n");
  68         }
  69         /* Output the load options */
  70         con_out->output_string(con_out, L"Load options: ");
  71         if (loaded_image->load_options_size && loaded_image->load_options)
  72                 con_out->output_string(con_out,
  73                                        (u16 *)loaded_image->load_options);
  74         else
  75                 con_out->output_string(con_out, L"<none>");
  76         con_out->output_string(con_out, L"\n");
  77
  78 out:
  79         boottime->exit(handle, ret, 0, NULL);
  80
  81         /* We should never arrive here */
  82         return ret;
  83 }