git.sur5r.net Git - u-boot/blob - lib/efi_loader/helloworld.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * EFI hello world
   4  *
   5  * Copyright (c) 2016 Google, Inc
   6  * Written by Simon Glass <sjg@chromium.org>
   7  *
   8  * This program demonstrates calling a boottime service.
   9  * It writes a greeting and the load options to the console.
  10  */
  11
  12 #include <common.h>
  13 #include <efi_api.h>
  14
  15 static const efi_guid_t loaded_image_guid = LOADED_IMAGE_GUID;
  16 static const efi_guid_t fdt_guid = EFI_FDT_GUID;
  17 static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_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         u16 rev[] = L"0.0.0";
  50
  51         con_out->output_string(con_out, L"Hello, world!\n");
  52
  53         /* Print the revision number */
  54         rev[0] = (systable->hdr.revision >> 16) + '0';
  55         rev[4] = systable->hdr.revision & 0xffff;
  56         for (; rev[4] >= 10;) {
  57                 rev[4] -= 10;
  58                 ++rev[2];
  59         }
  60         /* Third digit is only to be shown if non-zero */
  61         if (rev[4])
  62                 rev[4] += '0';
  63         else
  64                 rev[3] = 0;
  65
  66         con_out->output_string(con_out, L"Running on UEFI ");
  67         con_out->output_string(con_out, rev);
  68         con_out->output_string(con_out, L"\n");
  69
  70         /* Get the loaded image protocol */
  71         ret = boottime->handle_protocol(handle, &loaded_image_guid,
  72                                         (void **)&loaded_image);
  73         if (ret != EFI_SUCCESS) {
  74                 con_out->output_string(con_out,
  75                                        L"Cannot open loaded image protocol\n");
  76                 goto out;
  77         }
  78         /* Find configuration tables */
  79         for (i = 0; i < systable->nr_tables; ++i) {
  80                 if (!hw_memcmp(&systable->tables[i].guid, &fdt_guid,
  81                                sizeof(efi_guid_t)))
  82                         con_out->output_string(con_out, L"Have device tree\n");
  83                 if (!hw_memcmp(&systable->tables[i].guid, &acpi_guid,
  84                                sizeof(efi_guid_t)))
  85                         con_out->output_string(con_out, L"Have ACPI 2.0 table\n");
  86                 if (!hw_memcmp(&systable->tables[i].guid, &smbios_guid,
  87                                sizeof(efi_guid_t)))
  88                         con_out->output_string(con_out, L"Have SMBIOS table\n");
  89         }
  90         /* Output the load options */
  91         con_out->output_string(con_out, L"Load options: ");
  92         if (loaded_image->load_options_size && loaded_image->load_options)
  93                 con_out->output_string(con_out,
  94                                        (u16 *)loaded_image->load_options);
  95         else
  96                 con_out->output_string(con_out, L"<none>");
  97         con_out->output_string(con_out, L"\n");
  98
  99 out:
 100         boottime->exit(handle, ret, 0, NULL);
 101
 102         /* We should never arrive here */
 103         return ret;
 104 }