include/efi_variable.h

/* SPDX-License-Identifier: GPL-2.0+ */
/*
 * Copyright (c) 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
 */

#ifndef _EFI_VARIABLE_H
#define _EFI_VARIABLE_H

#include <linux/bitops.h>

#define EFI_VARIABLE_READ_ONLY BIT(31)

/**
 * efi_get_variable() - retrieve value of a UEFI variable
 *
 * @variable_name:	name of the variable
 * @vendor:		vendor GUID
 * @attributes:		attributes of the variable
 * @data_size:		size of the buffer to which the variable value is copied
 * @data:		buffer to which the variable value is copied
 * @timep:		authentication time (seconds since start of epoch)
 * Return:		status code
 */
efi_status_t efi_get_variable_int(u16 *variable_name, const efi_guid_t *vendor,
				  u32 *attributes, efi_uintn_t *data_size,
				  void *data, u64 *timep);

/**
 * efi_set_variable() - set value of a UEFI variable
 *
 * @variable_name:	name of the variable
 * @vendor:		vendor GUID
 * @attributes:		attributes of the variable
 * @data_size:		size of the buffer with the variable value
 * @data:		buffer with the variable value
 * @ro_check:		check the read only read only bit in attributes
 * Return:		status code
 */
efi_status_t efi_set_variable_int(u16 *variable_name, const efi_guid_t *vendor,
				  u32 attributes, efi_uintn_t data_size,
				  const void *data, bool ro_check);

/**
 * efi_get_next_variable_name_int() - enumerate the current variable names
 *
 * @variable_name_size:	size of variable_name buffer in byte
 * @variable_name:	name of uefi variable's name in u16
 * @vendor:		vendor's guid
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * Return: status code
 */
efi_status_t efi_get_next_variable_name_int(efi_uintn_t *variable_name_size,
					    u16 *variable_name,
					    efi_guid_t *vendor);

/**
 * efi_query_variable_info_int() - get information about EFI variables
 *
 * This function implements the QueryVariableInfo() runtime service.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @attributes:				bitmask to select variables to be
 *					queried
 * @maximum_variable_storage_size:	maximum size of storage area for the
 *					selected variable types
 * @remaining_variable_storage_size:	remaining size of storage are for the
 *					selected variable types
 * @maximum_variable_size:		maximum size of a variable of the
 *					selected type
 * Returns:				status code
 */
efi_status_t efi_query_variable_info_int(u32 attributes,
					 u64 *maximum_variable_storage_size,
					 u64 *remaining_variable_storage_size,
					 u64 *maximum_variable_size);

#endif