1 # SPDX-License-Identifier: GPL-2.0-only
2 menu "EFI (Extensible Firmware Interface) Support"
6 tristate "EFI Variable Support via sysfs"
10 If you say Y here, you are able to get EFI (Extensible Firmware
11 Interface) variable information via sysfs. You may read,
12 write, create, and destroy EFI variables through this interface.
14 Note that using this driver in concert with efibootmgr requires
15 at least test release version 0.5.0-test3 or later, which is
17 <http://linux.dell.com/efibootmgr/testing/efibootmgr-0.5.0-test3.tar.gz>
19 Subsequent efibootmgr releases may be found at:
20 <http://github.com/vathpela/efibootmgr>
24 depends on EFI && !IA64
27 config EFI_VARS_PSTORE
28 tristate "Register efivars backend for pstore"
29 depends on EFI_VARS && PSTORE
32 Say Y here to enable use efivars as a backend to pstore. This
33 will allow writing console messages, crash dumps, or anything
34 else supported by pstore to EFI variables.
36 config EFI_VARS_PSTORE_DEFAULT_DISABLE
37 bool "Disable using efivars as a pstore backend by default"
38 depends on EFI_VARS_PSTORE
41 Saying Y here will disable the use of efivars as a storage
42 backend for pstore by default. This setting can be overridden
43 using the efivars module's pstore_disable parameter.
45 config EFI_RUNTIME_MAP
46 bool "Export efi runtime maps to sysfs"
47 depends on X86 && EFI && KEXEC_CORE
50 Export efi runtime memory maps to /sys/firmware/efi/runtime-map.
51 That memory map is used for example by kexec to set up efi virtual
52 mapping the 2nd kernel, but can also be used for debugging purposes.
54 See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
56 config EFI_FAKE_MEMMAP
57 bool "Enable EFI fake memory map"
61 Saying Y here will enable "efi_fake_mem" boot option.
62 By specifying this parameter, you can add arbitrary attribute
63 to specific memory range by updating original (firmware provided)
65 This is useful for debugging of EFI memmap related feature.
66 e.g. Address Range Mirroring feature.
68 config EFI_MAX_FAKE_MEM
69 int "maximum allowable number of ranges in efi_fake_mem boot option"
70 depends on EFI_FAKE_MEMMAP
74 Maximum allowable number of ranges in efi_fake_mem boot option.
75 Ranges can be set up to this value using comma-separated list.
76 The default value is 8.
78 config EFI_PARAMS_FROM_FDT
81 Select this config option from the architecture Kconfig if
82 the EFI runtime support gets system table address, memory
83 map address, and other parameters from the device tree.
85 config EFI_RUNTIME_WRAPPERS
91 config EFI_ARMSTUB_DTB_LOADER
92 bool "Enable the DTB loader"
93 depends on EFI_ARMSTUB
96 Select this config option to add support for the dtb= command
97 line parameter, allowing a device tree blob to be loaded into
98 memory from the EFI System Partition by the stub.
100 If the device tree is provided by the platform or by
101 the bootloader this option may not be needed.
102 But, for various development reasons and to maintain existing
103 functionality for bootloaders that do not have such support
104 this option is necessary.
106 config EFI_BOOTLOADER_CONTROL
107 tristate "EFI Bootloader Control"
111 This module installs a reboot hook, such that if reboot() is
112 invoked with a string argument NNN, "NNN" is copied to the
113 "LoaderEntryOneShot" EFI variable, to be read by the
114 bootloader. If the string matches one of the boot labels
115 defined in its configuration, the bootloader will boot once
116 to that label. The "LoaderEntryRebootReason" EFI variable is
117 set with the reboot reason: "reboot" or "shutdown". The
118 bootloader reads this reboot reason and takes particular
119 action according to its policy.
121 config EFI_CAPSULE_LOADER
122 tristate "EFI capsule loader"
125 This option exposes a loader interface "/dev/efi_capsule_loader" for
126 users to load EFI capsules. This driver requires working runtime
127 capsule support in the firmware, which many OEMs do not provide.
129 Most users should say N.
131 config EFI_CAPSULE_QUIRK_QUARK_CSH
132 bool "Add support for Quark capsules with non-standard headers"
133 depends on X86 && !64BIT
134 select EFI_CAPSULE_LOADER
137 Add support for processing Quark X1000 EFI capsules, whose header
138 layout deviates from the layout mandated by the UEFI specification.
141 tristate "EFI Runtime Service Tests Support"
145 This driver uses the efi.<service> function pointers directly instead
146 of going through the efivar API, because it is not trying to test the
147 kernel subsystem, just for testing the UEFI runtime service
148 interfaces which are provided by the firmware. This driver is used
149 by the Firmware Test Suite (FWTS) for testing the UEFI runtime
150 interfaces readiness of the firmware.
151 Details for FWTS are available from:
152 <https://wiki.ubuntu.com/FirmwareTestSuite>
154 Say Y here to enable the runtime services support via /dev/efi_test.
157 config APPLE_PROPERTIES
158 bool "Apple Device Properties"
159 depends on EFI_STUB && X86
160 select EFI_DEV_PATH_PARSER
163 Retrieve properties from EFI on Apple Macs and assign them to
164 devices, allowing for improved support of Apple hardware.
165 Properties that would otherwise be missing include the
166 Thunderbolt Device ROM and GPU configuration data.
168 If unsure, say Y if you have a Mac. Otherwise N.
170 config RESET_ATTACK_MITIGATION
171 bool "Reset memory attack mitigation"
174 Request that the firmware clear the contents of RAM after a reboot
175 using the TCG Platform Reset Attack Mitigation specification. This
176 protects against an attacker forcibly rebooting the system while it
177 still contains secrets in RAM, booting another OS and extracting the
178 secrets. This should only be enabled when userland is configured to
179 clear the MemoryOverwriteRequest flag on clean shutdown after secrets
180 have been evicted, since otherwise it will trigger even on clean
183 config EFI_RCI2_TABLE
184 bool "EFI Runtime Configuration Interface Table Version 2 Support"
186 Displays the content of the Runtime Configuration Interface
187 Table version 2 on Dell EMC PowerEdge systems as a binary
188 attribute 'rci2' under /sys/firmware/efi/tables directory.
190 RCI2 table contains BIOS HII in XML format and is used to populate
191 BIOS setup page in Dell EMC OpenManage Server Administrator tool.
192 The BIOS setup page contains BIOS tokens which can be configured.
194 Say Y here for Dell EMC PowerEdge systems.
203 depends on UEFI_CPER && ( ARM || ARM64 )
208 depends on UEFI_CPER && X86
211 config EFI_DEV_PATH_PARSER
218 depends on SERIAL_EARLYCON && !ARM && !IA64
220 select ARCH_USE_MEMREMAP_PROT