xref: /openbmc/linux/drivers/firmware/efi/Kconfig (revision c1d3fb8a) 
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_SOFT_RESERVE
79	bool "Reserve EFI Specific Purpose Memory"
80	depends on EFI && EFI_STUB && ACPI_HMAT
81	default ACPI_HMAT
82	help
83	  On systems that have mixed performance classes of memory EFI
84	  may indicate specific purpose memory with an attribute (See
85	  EFI_MEMORY_SP in UEFI 2.8). A memory range tagged with this
86	  attribute may have unique performance characteristics compared
87	  to the system's general purpose "System RAM" pool. On the
88	  expectation that such memory has application specific usage,
89	  and its base EFI memory type is "conventional" answer Y to
90	  arrange for the kernel to reserve it as a "Soft Reserved"
91	  resource, and set aside for direct-access (device-dax) by
92	  default. The memory range can later be optionally assigned to
93	  the page allocator by system administrator policy via the
94	  device-dax kmem facility. Say N to have the kernel treat this
95	  memory as "System RAM" by default.
96
97	  If unsure, say Y.
98
99config EFI_PARAMS_FROM_FDT
100	bool
101	help
102	  Select this config option from the architecture Kconfig if
103	  the EFI runtime support gets system table address, memory
104          map address, and other parameters from the device tree.
105
106config EFI_RUNTIME_WRAPPERS
107	bool
108
109config EFI_ARMSTUB
110	bool
111
112config EFI_ARMSTUB_DTB_LOADER
113	bool "Enable the DTB loader"
114	depends on EFI_ARMSTUB
115	default y
116	help
117	  Select this config option to add support for the dtb= command
118	  line parameter, allowing a device tree blob to be loaded into
119	  memory from the EFI System Partition by the stub.
120
121	  If the device tree is provided by the platform or by
122	  the bootloader this option may not be needed.
123	  But, for various development reasons and to maintain existing
124	  functionality for bootloaders that do not have such support
125	  this option is necessary.
126
127config EFI_BOOTLOADER_CONTROL
128	tristate "EFI Bootloader Control"
129	depends on EFI_VARS
130	default n
131	---help---
132	  This module installs a reboot hook, such that if reboot() is
133	  invoked with a string argument NNN, "NNN" is copied to the
134	  "LoaderEntryOneShot" EFI variable, to be read by the
135	  bootloader. If the string matches one of the boot labels
136	  defined in its configuration, the bootloader will boot once
137	  to that label. The "LoaderEntryRebootReason" EFI variable is
138	  set with the reboot reason: "reboot" or "shutdown". The
139	  bootloader reads this reboot reason and takes particular
140	  action according to its policy.
141
142config EFI_CAPSULE_LOADER
143	tristate "EFI capsule loader"
144	depends on EFI
145	help
146	  This option exposes a loader interface "/dev/efi_capsule_loader" for
147	  users to load EFI capsules. This driver requires working runtime
148	  capsule support in the firmware, which many OEMs do not provide.
149
150	  Most users should say N.
151
152config EFI_CAPSULE_QUIRK_QUARK_CSH
153	bool "Add support for Quark capsules with non-standard headers"
154	depends on X86 && !64BIT
155	select EFI_CAPSULE_LOADER
156	default y
157	help
158	  Add support for processing Quark X1000 EFI capsules, whose header
159	  layout deviates from the layout mandated by the UEFI specification.
160
161config EFI_TEST
162	tristate "EFI Runtime Service Tests Support"
163	depends on EFI
164	default n
165	help
166	  This driver uses the efi.<service> function pointers directly instead
167	  of going through the efivar API, because it is not trying to test the
168	  kernel subsystem, just for testing the UEFI runtime service
169	  interfaces which are provided by the firmware. This driver is used
170	  by the Firmware Test Suite (FWTS) for testing the UEFI runtime
171	  interfaces readiness of the firmware.
172	  Details for FWTS are available from:
173	  <https://wiki.ubuntu.com/FirmwareTestSuite>
174
175	  Say Y here to enable the runtime services support via /dev/efi_test.
176	  If unsure, say N.
177
178config APPLE_PROPERTIES
179	bool "Apple Device Properties"
180	depends on EFI_STUB && X86
181	select EFI_DEV_PATH_PARSER
182	select UCS2_STRING
183	help
184	  Retrieve properties from EFI on Apple Macs and assign them to
185	  devices, allowing for improved support of Apple hardware.
186	  Properties that would otherwise be missing include the
187	  Thunderbolt Device ROM and GPU configuration data.
188
189	  If unsure, say Y if you have a Mac.  Otherwise N.
190
191config RESET_ATTACK_MITIGATION
192	bool "Reset memory attack mitigation"
193	depends on EFI_STUB
194	help
195	  Request that the firmware clear the contents of RAM after a reboot
196	  using the TCG Platform Reset Attack Mitigation specification. This
197	  protects against an attacker forcibly rebooting the system while it
198	  still contains secrets in RAM, booting another OS and extracting the
199	  secrets. This should only be enabled when userland is configured to
200	  clear the MemoryOverwriteRequest flag on clean shutdown after secrets
201	  have been evicted, since otherwise it will trigger even on clean
202	  reboots.
203
204config EFI_RCI2_TABLE
205	bool "EFI Runtime Configuration Interface Table Version 2 Support"
206	depends on X86 || COMPILE_TEST
207	help
208	  Displays the content of the Runtime Configuration Interface
209	  Table version 2 on Dell EMC PowerEdge systems as a binary
210	  attribute 'rci2' under /sys/firmware/efi/tables directory.
211
212	  RCI2 table contains BIOS HII in XML format and is used to populate
213	  BIOS setup page in Dell EMC OpenManage Server Administrator tool.
214	  The BIOS setup page contains BIOS tokens which can be configured.
215
216	  Say Y here for Dell EMC PowerEdge systems.
217
218endmenu
219
220config UEFI_CPER
221	bool
222
223config UEFI_CPER_ARM
224	bool
225	depends on UEFI_CPER && ( ARM || ARM64 )
226	default y
227
228config UEFI_CPER_X86
229	bool
230	depends on UEFI_CPER && X86
231	default y
232
233config EFI_DEV_PATH_PARSER
234	bool
235	depends on ACPI
236	default n
237
238config EFI_EARLYCON
239	def_bool y
240	depends on SERIAL_EARLYCON && !ARM && !IA64
241	select FONT_SUPPORT
242	select ARCH_USE_MEMREMAP_PROT
243