lib/efi/efi_info.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2015 Google, Inc
   4  *
   5  * Access to the EFI information table
   6  */
   7
   8 #include <efi.h>
   9 #include <errno.h>
  10 #include <mapmem.h>
  11 #include <asm/global_data.h>
  12
  13 int efi_info_get(enum efi_entry_t type, void **datap, int *sizep)
  14 {
  15         struct efi_entry_hdr *entry;
  16         struct efi_info_hdr *info;
  17         int ret;
  18
  19         if (!gd->arch.table)
  20                 return -ENODATA;
  21
  22         info = map_sysmem(gd->arch.table, 0);
  23         if (info->version != EFI_TABLE_VERSION) {
  24                 ret = -EPROTONOSUPPORT;
  25                 goto err;
  26         }
  27
  28         entry = (struct efi_entry_hdr *)((ulong)info + info->hdr_size);
  29         while (entry->type != EFIET_END) {
  30                 if (entry->type == type) {
  31                         if (entry->addr)
  32                                 *datap = map_sysmem(entry->addr, entry->size);
  33                         else
  34                                 *datap = entry + 1;
  35                         *sizep = entry->size;
  36                         return 0;
  37                 }
  38                 entry = (struct efi_entry_hdr *)((ulong)entry + entry->link);
  39         }
  40
  41         ret = -ENOENT;
  42 err:
  43         unmap_sysmem(info);
  44
  45         return ret;
  46 }