| /* 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 (1<<31) |
| |
| enum efi_auth_var_type { |
| EFI_AUTH_VAR_NONE = 0, |
| EFI_AUTH_MODE, |
| 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(const 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(const 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 CONFIG_EFI_VAR_BUF_SIZE |
| |
| /* |
| * 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 |
| * |
| * Only if @safe is set secure boot related variables will be restored. |
| * |
| * @buf: buffer |
| * @safe: restoring from tamper-resistant storage |
| * Return: status code |
| */ |
| efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe); |
| |
| /** |
| * 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(const 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(const u16 *name, |
| const efi_guid_t *guid); |
| |
| /** |
| * efi_auth_var_get_guid() - get the predefined GUID for a variable name |
| * |
| * @name: name of UEFI variable |
| * Return: guid of UEFI variable |
| */ |
| const efi_guid_t *efi_auth_var_get_guid(const u16 *name); |
| |
| /** |
| * 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 bytes |
| * @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(const 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); |
| |
| /** |
| * efi_var_buf_update() - udpate memory buffer for variables |
| * |
| * @var_buf: source buffer |
| * |
| * This function copies to the memory buffer for UEFI variables. Call this |
| * function in ExitBootServices() if memory backed variables are only used |
| * at runtime to fill the buffer. |
| */ |
| void efi_var_buf_update(struct efi_var_file *var_buf); |
| |
| #endif |