include/efi_variable.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Copyright (c) 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
   4  */
   5
   6 #ifndef _EFI_VARIABLE_H
   7 #define _EFI_VARIABLE_H
   8
   9 #include <linux/bitops.h>
  10
  11 #define EFI_VARIABLE_READ_ONLY BIT(31)
  12
  13 /**
  14  * efi_get_variable() - retrieve value of a UEFI variable
  15  *
  16  * @variable_name:      name of the variable
  17  * @vendor:             vendor GUID
  18  * @attributes:         attributes of the variable
  19  * @data_size:          size of the buffer to which the variable value is copied
  20  * @data:               buffer to which the variable value is copied
  21  * @timep:              authentication time (seconds since start of epoch)
  22  * Return:              status code
  23  */
  24 efi_status_t efi_get_variable_int(u16 *variable_name, const efi_guid_t *vendor,
  25                                   u32 *attributes, efi_uintn_t *data_size,
  26                                   void *data, u64 *timep);
  27
  28 /**
  29  * efi_set_variable() - set value of a UEFI variable
  30  *
  31  * @variable_name:      name of the variable
  32  * @vendor:             vendor GUID
  33  * @attributes:         attributes of the variable
  34  * @data_size:          size of the buffer with the variable value
  35  * @data:               buffer with the variable value
  36  * @ro_check:           check the read only read only bit in attributes
  37  * Return:              status code
  38  */
  39 efi_status_t efi_set_variable_int(u16 *variable_name, const efi_guid_t *vendor,
  40                                   u32 attributes, efi_uintn_t data_size,
  41                                   const void *data, bool ro_check);
  42
  43 /**
  44  * efi_get_next_variable_name_int() - enumerate the current variable names
  45  *
  46  * @variable_name_size: size of variable_name buffer in byte
  47  * @variable_name:      name of uefi variable's name in u16
  48  * @vendor:             vendor's guid
  49  *
  50  * See the Unified Extensible Firmware Interface (UEFI) specification for
  51  * details.
  52  *
  53  * Return: status code
  54  */
  55 efi_status_t efi_get_next_variable_name_int(efi_uintn_t *variable_name_size,
  56                                             u16 *variable_name,
  57                                             efi_guid_t *vendor);
  58
  59 /**
  60  * efi_query_variable_info_int() - get information about EFI variables
  61  *
  62  * This function implements the QueryVariableInfo() runtime service.
  63  *
  64  * See the Unified Extensible Firmware Interface (UEFI) specification for
  65  * details.
  66  *
  67  * @attributes:                         bitmask to select variables to be
  68  *                                      queried
  69  * @maximum_variable_storage_size:      maximum size of storage area for the
  70  *                                      selected variable types
  71  * @remaining_variable_storage_size:    remaining size of storage are for the
  72  *                                      selected variable types
  73  * @maximum_variable_size:              maximum size of a variable of the
  74  *                                      selected type
  75  * Returns:                             status code
  76  */
  77 efi_status_t efi_query_variable_info_int(u32 attributes,
  78                                          u64 *maximum_variable_storage_size,
  79                                          u64 *remaining_variable_storage_size,
  80                                          u64 *maximum_variable_size);
  81
  82 #endif