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- /* 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)
- enum efi_auth_var_type {
- EFI_AUTH_VAR_NONE = 0,
- EFI_AUTH_VAR_PK,
- EFI_AUTH_VAR_KEK,
- EFI_AUTH_VAR_DB,
- EFI_AUTH_VAR_DBX,
- EFI_AUTH_VAR_DBT,
- EFI_AUTH_VAR_DBR,
- };
- /**
- * 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);
- #define EFI_VAR_FILE_NAME "ubootefi.var"
- #define EFI_VAR_BUF_SIZE 0x4000
- /*
- * This constant identifies the file format for storing UEFI variables in
- * struct efi_var_file.
- */
- #define EFI_VAR_FILE_MAGIC 0x0161566966456255 /* UbEfiVa, version 1 */
- /**
- * struct efi_var_entry - UEFI variable file entry
- *
- * @length: length of enty, multiple of 8
- * @attr: variable attributes
- * @time: authentication time (seconds since start of epoch)
- * @guid: vendor GUID
- * @name: UTF16 variable name
- */
- struct efi_var_entry {
- u32 length;
- u32 attr;
- u64 time;
- efi_guid_t guid;
- u16 name[];
- };
- /**
- * struct efi_var_file - file for storing UEFI variables
- *
- * @reserved: unused, may be overwritten by memory probing
- * @magic: identifies file format, takes value %EFI_VAR_FILE_MAGIC
- * @length: length including header
- * @crc32: CRC32 without header
- * @var: variables
- */
- struct efi_var_file {
- u64 reserved;
- u64 magic;
- u32 length;
- u32 crc32;
- struct efi_var_entry var[];
- };
- /**
- * efi_var_to_file() - save non-volatile variables as file
- *
- * File ubootefi.var is created on the EFI system partion.
- *
- * Return: status code
- */
- efi_status_t efi_var_to_file(void);
- /**
- * efi_var_collect() - collect variables in buffer
- *
- * A buffer is allocated and filled with variables in a format ready to be
- * written to disk.
- *
- * @bufp: pointer to pointer of buffer with collected variables
- * @lenp: pointer to length of buffer
- * @check_attr_mask: bitmask with required attributes of variables to be collected.
- * variables are only collected if all of the required
- * attributes are set.
- * Return: status code
- */
- efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *lenp,
- u32 check_attr_mask);
- /**
- * efi_var_restore() - restore EFI variables from buffer
- *
- * @buf: buffer
- * Return: status code
- */
- efi_status_t efi_var_restore(struct efi_var_file *buf);
- /**
- * efi_var_from_file() - read variables from file
- *
- * File ubootefi.var is read from the EFI system partitions and the variables
- * stored in the file are created.
- *
- * In case the file does not exist yet or a variable cannot be set EFI_SUCCESS
- * is returned.
- *
- * Return: status code
- */
- efi_status_t efi_var_from_file(void);
- /**
- * efi_var_mem_init() - set-up variable list
- *
- * Return: status code
- */
- efi_status_t efi_var_mem_init(void);
- /**
- * efi_var_mem_find() - find a variable in the list
- *
- * @guid: GUID of the variable
- * @name: name of the variable
- * @next: on exit pointer to the next variable after the found one
- * Return: found variable
- */
- struct efi_var_entry *efi_var_mem_find(const efi_guid_t *guid, const u16 *name,
- struct efi_var_entry **next);
- /**
- * efi_var_mem_del() - delete a variable from the list of variables
- *
- * @var: variable to delete
- */
- void efi_var_mem_del(struct efi_var_entry *var);
- /**
- * efi_var_mem_ins() - append a variable to the list of variables
- *
- * The variable is appended without checking if a variable of the same name
- * already exists. The two data buffers are concatenated.
- *
- * @variable_name: variable name
- * @vendor: GUID
- * @attributes: variable attributes
- * @size1: size of the first data buffer
- * @data1: first data buffer
- * @size2: size of the second data field
- * @data2: second data buffer
- * @time: time of authentication (as seconds since start of epoch)
- * Result: status code
- */
- efi_status_t efi_var_mem_ins(u16 *variable_name,
- const efi_guid_t *vendor, u32 attributes,
- const efi_uintn_t size1, const void *data1,
- const efi_uintn_t size2, const void *data2,
- const u64 time);
- /**
- * efi_var_mem_free() - determine free memory for variables
- *
- * Return: maximum data size plus variable name size
- */
- u64 efi_var_mem_free(void);
- /**
- * efi_init_secure_state - initialize secure boot state
- *
- * Return: status code
- */
- efi_status_t efi_init_secure_state(void);
- /**
- * efi_auth_var_get_type() - convert variable name and guid to enum
- *
- * @name: name of UEFI variable
- * @guid: guid of UEFI variable
- * Return: identifier for authentication related variables
- */
- enum efi_auth_var_type efi_auth_var_get_type(u16 *name, const efi_guid_t *guid);
- /**
- * efi_get_next_variable_name_mem() - Runtime common code across efi variable
- * implementations for GetNextVariable()
- * from the cached memory copy
- * @variable_name_size: size of variable_name buffer in byte
- * @variable_name: name of uefi variable's name in u16
- * @vendor: vendor's guid
- *
- * Return: status code
- */
- efi_status_t __efi_runtime
- efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, u16 *variable_name,
- efi_guid_t *vendor);
- /**
- * efi_get_variable_mem() - Runtime common code across efi variable
- * implementations for GetVariable() from
- * the cached memory copy
- *
- * @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_runtime
- efi_get_variable_mem(u16 *variable_name, const efi_guid_t *vendor, u32 *attributes,
- efi_uintn_t *data_size, void *data, u64 *timep);
- /**
- * efi_get_variable_runtime() - runtime implementation of GetVariable()
- *
- * @variable_name: name of the variable
- * @guid: 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
- * Return: status code
- */
- efi_status_t __efi_runtime EFIAPI
- efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *guid,
- u32 *attributes, efi_uintn_t *data_size, void *data);
- /**
- * efi_get_next_variable_name_runtime() - runtime implementation of
- * GetNextVariable()
- *
- * @variable_name_size: size of variable_name buffer in byte
- * @variable_name: name of uefi variable's name in u16
- * @guid: vendor's guid
- * Return: status code
- */
- efi_status_t __efi_runtime EFIAPI
- efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
- u16 *variable_name, efi_guid_t *guid);
- #endif
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