xref: /openbmc/linux/drivers/firmware/efi/Kconfig (revision c24c57a4) 
1# SPDX-License-Identifier: GPL-2.0-only
2menu "EFI (Extensible Firmware Interface) Support"
3	depends on EFI
4
5config EFI_VARS
6	tristate "EFI Variable Support via sysfs"
7	depends on EFI
8	default n
9	help
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.
13
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
16	  available from:
17	  <http://linux.dell.com/efibootmgr/testing/efibootmgr-0.5.0-test3.tar.gz>
18
19	  Subsequent efibootmgr releases may be found at:
20	  <http://github.com/vathpela/efibootmgr>
21
22config EFI_ESRT
23	bool
24	depends on EFI && !IA64
25	default y
26
27config EFI_VARS_PSTORE
28	tristate "Register efivars backend for pstore"
29	depends on EFI_VARS && PSTORE
30	default y
31	help
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.
35
36config EFI_VARS_PSTORE_DEFAULT_DISABLE
37	bool "Disable using efivars as a pstore backend by default"
38	depends on EFI_VARS_PSTORE
39	default n
40	help
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.
44
45config EFI_RUNTIME_MAP
46	bool "Export efi runtime maps to sysfs"
47	depends on X86 && EFI && KEXEC_CORE
48	default y
49	help
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.
53
54	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
55
56config EFI_FAKE_MEMMAP
57	bool "Enable EFI fake memory map"
58	depends on EFI && X86
59	default n
60	help
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)
64	  EFI memmap.
65	  This is useful for debugging of EFI memmap related feature.
66	  e.g. Address Range Mirroring feature.
67
68config EFI_MAX_FAKE_MEM
69	int "maximum allowable number of ranges in efi_fake_mem boot option"
70	depends on EFI_FAKE_MEMMAP
71	range 1 128
72	default 8
73	help
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.
77
78config EFI_PARAMS_FROM_FDT
79	bool
80	help
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.
84
85config EFI_RUNTIME_WRAPPERS
86	bool
87
88config EFI_ARMSTUB
89	bool
90
91config EFI_ARMSTUB_DTB_LOADER
92	bool "Enable the DTB loader"
93	depends on EFI_ARMSTUB
94	default y
95	help
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.
99
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.
105
106config EFI_BOOTLOADER_CONTROL
107	tristate "EFI Bootloader Control"
108	depends on EFI_VARS
109	default n
110	---help---
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.
120
121config EFI_CAPSULE_LOADER
122	tristate "EFI capsule loader"
123	depends on EFI
124	help
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.
128
129	  Most users should say N.
130
131config 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
135	default y
136	help
137	  Add support for processing Quark X1000 EFI capsules, whose header
138	  layout deviates from the layout mandated by the UEFI specification.
139
140config EFI_TEST
141	tristate "EFI Runtime Service Tests Support"
142	depends on EFI
143	default n
144	help
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>
153
154	  Say Y here to enable the runtime services support via /dev/efi_test.
155	  If unsure, say N.
156
157config APPLE_PROPERTIES
158	bool "Apple Device Properties"
159	depends on EFI_STUB && X86
160	select EFI_DEV_PATH_PARSER
161	select UCS2_STRING
162	help
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.
167
168	  If unsure, say Y if you have a Mac.  Otherwise N.
169
170config RESET_ATTACK_MITIGATION
171	bool "Reset memory attack mitigation"
172	depends on EFI_STUB
173	help
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
181	  reboots.
182
183config EFI_RCI2_TABLE
184	bool "EFI Runtime Configuration Interface Table Version 2 Support"
185	depends on X86 || COMPILE_TEST
186	help
187	  Displays the content of the Runtime Configuration Interface
188	  Table version 2 on Dell EMC PowerEdge systems as a binary
189	  attribute 'rci2' under /sys/firmware/efi/tables directory.
190
191	  RCI2 table contains BIOS HII in XML format and is used to populate
192	  BIOS setup page in Dell EMC OpenManage Server Administrator tool.
193	  The BIOS setup page contains BIOS tokens which can be configured.
194
195	  Say Y here for Dell EMC PowerEdge systems.
196
197endmenu
198
199config UEFI_CPER
200	bool
201
202config UEFI_CPER_ARM
203	bool
204	depends on UEFI_CPER && ( ARM || ARM64 )
205	default y
206
207config UEFI_CPER_X86
208	bool
209	depends on UEFI_CPER && X86
210	default y
211
212config EFI_DEV_PATH_PARSER
213	bool
214	depends on ACPI
215	default n
216
217config EFI_EARLYCON
218	def_bool y
219	depends on SERIAL_EARLYCON && !ARM && !IA64
220	select FONT_SUPPORT
221	select ARCH_USE_MEMREMAP_PROT
222