diff options
Diffstat (limited to 'drivers/firmware/efi/Kconfig')
| -rw-r--r-- | drivers/firmware/efi/Kconfig | 338 |
1 files changed, 322 insertions, 16 deletions
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index b0fc7c79dfbb..29e0729299f5 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -1,26 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0-only menu "EFI (Extensible Firmware Interface) Support" depends on EFI -config EFI_VARS - tristate "EFI Variable Support via sysfs" +config EFI_ESRT + bool depends on EFI - default n - help - If you say Y here, you are able to get EFI (Extensible Firmware - Interface) variable information via sysfs. You may read, - write, create, and destroy EFI variables through this interface. - - Note that using this driver in concert with efibootmgr requires - at least test release version 0.5.0-test3 or later, which is - available from Matt Domsch's website located at: - <http://linux.dell.com/efibootmgr/testing/efibootmgr-0.5.0-test3.tar.gz> - - Subsequent efibootmgr releases may be found at: - <http://linux.dell.com/efibootmgr> + default y config EFI_VARS_PSTORE tristate "Register efivars backend for pstore" - depends on EFI_VARS && PSTORE + depends on PSTORE + select UCS2_STRING default y help Say Y here to enable use efivars as a backend to pstore. This @@ -36,4 +26,320 @@ config EFI_VARS_PSTORE_DEFAULT_DISABLE backend for pstore by default. This setting can be overridden using the efivars module's pstore_disable parameter. +config EFI_SOFT_RESERVE + bool "Reserve EFI Specific Purpose Memory" + depends on EFI && EFI_STUB && ACPI_HMAT + default ACPI_HMAT + help + On systems that have mixed performance classes of memory EFI + may indicate specific purpose memory with an attribute (See + EFI_MEMORY_SP in UEFI 2.8). A memory range tagged with this + attribute may have unique performance characteristics compared + to the system's general purpose "System RAM" pool. On the + expectation that such memory has application specific usage, + and its base EFI memory type is "conventional" answer Y to + arrange for the kernel to reserve it as a "Soft Reserved" + resource, and set aside for direct-access (device-dax) by + default. The memory range can later be optionally assigned to + the page allocator by system administrator policy via the + device-dax kmem facility. Say N to have the kernel treat this + memory as "System RAM" by default. + + If unsure, say Y. + +config EFI_DXE_MEM_ATTRIBUTES + bool "Adjust memory attributes in EFISTUB" + depends on EFI && EFI_STUB && X86 + default y + help + UEFI specification does not guarantee all memory to be + accessible for both write and execute as the kernel expects + it to be. + Use DXE services to check and alter memory protection + attributes during boot via EFISTUB to ensure that memory + ranges used by the kernel are writable and executable. + +config EFI_PARAMS_FROM_FDT + bool + help + Select this config option from the architecture Kconfig if + the EFI runtime support gets system table address, memory + map address, and other parameters from the device tree. + +config EFI_RUNTIME_WRAPPERS + bool + +config EFI_GENERIC_STUB + bool + +config EFI_ZBOOT + bool "Enable the generic EFI decompressor" + depends on EFI_GENERIC_STUB && !ARM + select HAVE_KERNEL_GZIP + select HAVE_KERNEL_ZSTD + help + Create the bootable image as an EFI application that carries the + actual kernel image in compressed form, and decompresses it into + memory before executing it. For compatibility with non-EFI loaders, + the payload can be decompressed and executed by the loader as well, + provided that the loader implements the decompression algorithm. + (The compression algorithm used is described in the zboot header) + +config EFI_ARMSTUB_DTB_LOADER + bool "Enable the DTB loader" + depends on EFI_GENERIC_STUB && !RISCV && !LOONGARCH + default y + help + Select this config option to add support for the dtb= command + line parameter, allowing a device tree blob to be loaded into + memory from the EFI System Partition by the stub. + + If the device tree is provided by the platform or by + the bootloader this option may not be needed. + But, for various development reasons and to maintain existing + functionality for bootloaders that do not have such support + this option is necessary. + +config EFI_BOOTLOADER_CONTROL + tristate "EFI Bootloader Control" + select UCS2_STRING + default n + help + This module installs a reboot hook, such that if reboot() is + invoked with a string argument NNN, "NNN" is copied to the + "LoaderEntryOneShot" EFI variable, to be read by the + bootloader. If the string matches one of the boot labels + defined in its configuration, the bootloader will boot once + to that label. The "LoaderEntryRebootReason" EFI variable is + set with the reboot reason: "reboot" or "shutdown". The + bootloader reads this reboot reason and takes particular + action according to its policy. + +config EFI_CAPSULE_LOADER + tristate "EFI capsule loader" + depends on EFI + help + This option exposes a loader interface "/dev/efi_capsule_loader" for + users to load EFI capsules. This driver requires working runtime + capsule support in the firmware, which many OEMs do not provide. + + Most users should say N. + +config EFI_CAPSULE_QUIRK_QUARK_CSH + bool "Add support for Quark capsules with non-standard headers" + depends on X86 && !64BIT + select EFI_CAPSULE_LOADER + default y + help + Add support for processing Quark X1000 EFI capsules, whose header + layout deviates from the layout mandated by the UEFI specification. + +config EFI_TEST + tristate "EFI Runtime Service Tests Support" + depends on EFI + default n + help + This driver uses the efi.<service> function pointers directly instead + of going through the efivar API, because it is not trying to test the + kernel subsystem, just for testing the UEFI runtime service + interfaces which are provided by the firmware. This driver is used + by the Firmware Test Suite (FWTS) for testing the UEFI runtime + interfaces readiness of the firmware. + Details for FWTS are available from: + <https://wiki.ubuntu.com/FirmwareTestSuite> + + Say Y here to enable the runtime services support via /dev/efi_test. + If unsure, say N. + +config EFI_DEV_PATH_PARSER + bool + +config APPLE_PROPERTIES + bool "Apple Device Properties" + depends on EFI_STUB && X86 + select EFI_DEV_PATH_PARSER + select UCS2_STRING + help + Retrieve properties from EFI on Apple Macs and assign them to + devices, allowing for improved support of Apple hardware. + Properties that would otherwise be missing include the + Thunderbolt Device ROM and GPU configuration data. + + If unsure, say Y if you have a Mac. Otherwise N. + +config RESET_ATTACK_MITIGATION + bool "Reset memory attack mitigation" + depends on EFI_STUB + help + Request that the firmware clear the contents of RAM after a reboot + using the TCG Platform Reset Attack Mitigation specification. This + protects against an attacker forcibly rebooting the system while it + still contains secrets in RAM, booting another OS and extracting the + secrets. This should only be enabled when userland is configured to + clear the MemoryOverwriteRequest flag on clean shutdown after secrets + have been evicted, since otherwise it will trigger even on clean + reboots. + +config EFI_RCI2_TABLE + bool "EFI Runtime Configuration Interface Table Version 2 Support" + depends on X86 || COMPILE_TEST + help + Displays the content of the Runtime Configuration Interface + Table version 2 on Dell EMC PowerEdge systems as a binary + attribute 'rci2' under /sys/firmware/efi/tables directory. + + RCI2 table contains BIOS HII in XML format and is used to populate + BIOS setup page in Dell EMC OpenManage Server Administrator tool. + The BIOS setup page contains BIOS tokens which can be configured. + + Say Y here for Dell EMC PowerEdge systems. + +config EFI_DISABLE_PCI_DMA + bool "Clear Busmaster bit on PCI bridges during ExitBootServices()" + help + Disable the busmaster bit in the control register on all PCI bridges + while calling ExitBootServices() and passing control to the runtime + kernel. System firmware may configure the IOMMU to prevent malicious + PCI devices from being able to attack the OS via DMA. However, since + firmware can't guarantee that the OS is IOMMU-aware, it will tear + down IOMMU configuration when ExitBootServices() is called. This + leaves a window between where a hostile device could still cause + damage before Linux configures the IOMMU again. + + If you say Y here, the EFI stub will clear the busmaster bit on all + PCI bridges before ExitBootServices() is called. This will prevent + any malicious PCI devices from being able to perform DMA until the + kernel reenables busmastering after configuring the IOMMU. + + This option will cause failures with some poorly behaved hardware + and should not be enabled without testing. The kernel commandline + options "efi=disable_early_pci_dma" or "efi=no_disable_early_pci_dma" + may be used to override this option. + +config EFI_EARLYCON + def_bool y + depends on SERIAL_EARLYCON && !ARM + select FONT_SUPPORT + select ARCH_USE_MEMREMAP_PROT + +config EFI_CUSTOM_SSDT_OVERLAYS + bool "Load custom ACPI SSDT overlay from an EFI variable" + depends on ACPI + default ACPI_TABLE_UPGRADE + help + Allow loading of an ACPI SSDT overlay from an EFI variable specified + by a kernel command line option. + + See Documentation/admin-guide/acpi/ssdt-overlays.rst for more + information. + +config EFI_DISABLE_RUNTIME + bool "Disable EFI runtime services support by default" + default y if PREEMPT_RT + help + Allow to disable the EFI runtime services support by default. This can + already be achieved by using the efi=noruntime option, but it could be + useful to have this default without any kernel command line parameter. + + The EFI runtime services are disabled by default when PREEMPT_RT is + enabled, because measurements have shown that some EFI functions calls + might take too much time to complete, causing large latencies which is + an issue for Real-Time kernels. + + This default can be overridden by using the efi=runtime option. + +config EFI_COCO_SECRET + bool "EFI Confidential Computing Secret Area Support" + help + Confidential Computing platforms (such as AMD SEV) allow the + Guest Owner to securely inject secrets during guest VM launch. + The secrets are placed in a designated EFI reserved memory area. + + In order to use the secrets in the kernel, the location of the secret + area (as published in the EFI config table) must be kept. + + If you say Y here, the address of the EFI secret area will be kept + for usage inside the kernel. This will allow the + virt/coco/efi_secret module to access the secrets, which in turn + allows userspace programs to access the injected secrets. + +config OVMF_DEBUG_LOG + bool "Expose OVMF firmware debug log via sysfs" + depends on EFI + help + Recent versions of the Open Virtual Machine Firmware + (edk2-stable202508 + newer) can write their debug log to a memory + buffer. This driver exposes the log content via sysfs + (/sys/firmware/efi/ovmf_debug_log). + +config UNACCEPTED_MEMORY + bool + depends on EFI_STUB + help + Some Virtual Machine platforms, such as Intel TDX, require + some memory to be "accepted" by the guest before it can be used. + This mechanism helps prevent malicious hosts from making changes + to guest memory. + + UEFI specification v2.9 introduced EFI_UNACCEPTED_MEMORY memory type. + + This option adds support for unaccepted memory and makes such memory + usable by the kernel. + +config EFI_EMBEDDED_FIRMWARE + bool + select CRYPTO_LIB_SHA256 + +config EFI_SBAT + def_bool y if EFI_SBAT_FILE!="" + +config EFI_SBAT_FILE + string "Embedded SBAT section file path" + depends on EFI_ZBOOT || (EFI_STUB && X86) + help + SBAT section provides a way to improve SecureBoot revocations of UEFI + binaries by introducing a generation-based mechanism. With SBAT, older + UEFI binaries can be prevented from booting by bumping the minimal + required generation for the specific component in the bootloader. + + Note: SBAT information is distribution specific, i.e. the owner of the + signing SecureBoot certificate must define the SBAT policy. Linux + kernel upstream does not define SBAT components and their generations. + + See https://github.com/rhboot/shim/blob/main/SBAT.md for the additional + details. + + Specify a file with SBAT data which is going to be embedded as '.sbat' + section into the kernel. + + If unsure, leave blank. + endmenu + +config UEFI_CPER + bool + +config UEFI_CPER_ARM + bool + depends on UEFI_CPER && ( ARM || ARM64 ) + default y + +config UEFI_CPER_X86 + bool + depends on UEFI_CPER && X86 + default y + +config TEE_STMM_EFI + tristate "TEE-based EFI runtime variable service driver" + depends on EFI && OPTEE + help + Select this config option if TEE is compiled to include StandAloneMM + as a separate secure partition. It has the ability to check and store + EFI variables on an RPMB or any other non-volatile medium used by + StandAloneMM. + + Enabling this will change the EFI runtime services from the firmware + provided functions to TEE calls. + + To compile this driver as a module, choose M here: the module + will be called tee_stmm_efi. |