![]() We want to be able to differenciate failures for a specific update method, e.g. finding if should be enabling CoD by default or not. |
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.. | ||
tests | ||
fu-plugin-uefi-capsule.c | ||
fu-self-test.c | ||
fu-ucs2.c | ||
fu-ucs2.h | ||
fu-uefi-backend-freebsd.c | ||
fu-uefi-backend-freebsd.h | ||
fu-uefi-backend-linux.c | ||
fu-uefi-backend-linux.h | ||
fu-uefi-backend.c | ||
fu-uefi-backend.h | ||
fu-uefi-bgrt.c | ||
fu-uefi-bgrt.h | ||
fu-uefi-bootmgr.c | ||
fu-uefi-bootmgr.h | ||
fu-uefi-cod-device.c | ||
fu-uefi-cod-device.h | ||
fu-uefi-common.c | ||
fu-uefi-common.h | ||
fu-uefi-device.c | ||
fu-uefi-device.h | ||
fu-uefi-devpath.c | ||
fu-uefi-devpath.h | ||
fu-uefi-grub-device.c | ||
fu-uefi-grub-device.h | ||
fu-uefi-nvram-device.c | ||
fu-uefi-nvram-device.h | ||
fu-uefi-pcrs.c | ||
fu-uefi-pcrs.h | ||
fu-uefi-tool.c | ||
fu-uefi-update-info.c | ||
fu-uefi-update-info.h | ||
fwupd.grub.conf.in | ||
fwupdate.1 | ||
make-images.py | ||
meson.build | ||
README.md | ||
uefi_capsule.conf | ||
uefi-capsule.quirk |
UEFI Capsule
Introduction
The Unified Extensible Firmware Interface (UEFI) is a specification that defines the software interface between an OS and platform firmware. With the UpdateCapsule boot service it can be used to update system firmware.
If you don't want or need this functionality you can use the
-Dplugin_uefi_capsule=false
option.
When this plugin is enabled, the companion UEFI binary may also be built from the fwupd-efi project if not already present on the filesystem.
This behavior can be overridden using the meson option -Defi_binary=false
.
For this companion binary to work with secure boot, it will need to be signed by an authority trusted with shim and/or the host environment.
Lenovo Specific Behavior
On Lenovo hardware only the boot label is set to Linux-Firmware-Updater
rather
than "Linux Firmware Updater" (with spaces) due to long-fixed EFI boot manager
bugs. Many users will have these old BIOS versions installed and so we use the
use-legacy-bootmgr-desc
quirk to use the safe name.
On some Lenovo hardware only one capsule is installable due to possible problems
with the UpdateCapsule coalesce operation. As soon as one UEFI device has been
scheduled for update the other UEFI devices found in the ESRT will be marked
as updatable-hidden
rather than updatable
. Rebooting will restore them so
they can be updated on next OS boot.
Firmware Format
The daemon will decompress the cabinet archive and extract a firmware blob in EFI capsule file format.
See the UEFI specification for details.
This plugin supports the following protocol ID:
- org.uefi.capsule
Update Behavior
Capsule update on-disk
Described in UEFI specification § 8.5.5 - Delivery of Capsules via file on Mass Storage device.
If the firmware supports this, it will be the preferred method of updating. You
can explicitly disable it by by modifying DisableCapsuleUpdateOnDisk in
/etc/fwupd/uefi_capsule.conf
.
The spec expects runtime SetVariable to be available in order to enable this
feature, we need to set EFI_OS_INDICATIONS_FILE_CAPSULE_DELIVERY_SUPPORTED
in OsIndications variable to trigger processing of submitted capsule on next
reboot. However some firmware implementations (e.g U-Boot), can't set the
variable at runtime, but ignore the variable in next reboot and apply the
capsule anyway.
The directory \EFI\UpdateCapsule is checked for capsules only within the EFI system partition on the device specified in the active boot option determine by reference to BootNext variable or BootOrder variable processing. Since setting BootNext, for capsule update on-disk, is not yet implemented, the only available option is place the \EFI\UpdateCapsule within the ESP partition indicated by the current BootOrder. Note that this will be always needed if your firmware doesn't support SetVariable at runtime (even if BootNext functionality is added).
Runtime capsule updates
The firmware is deployed when the OS is running, but it is only written when the
system has been restarted and the fwupd*.efi
binary has been run. To achieve
this fwupd sets up the EFI BootNext
variable, creating the new boot entry if
required.
GUID Generation
These devices use the UEFI GUID as provided in the ESRT. Additionally, for the
system device the main-system-firmware
GUID is also added.
For compatibility with Windows 10, the plugin also adds GUIDs of the form
UEFI\RES_{$(esrt)}
.
Vendor ID Security
The vendor ID is set from the BIOS vendor, for example DMI:LENOVO
for all
devices that are not marked as supporting Firmware Management Protocol. For FMP
device no vendor ID is set.
UEFI Unlock Support
On some Dell systems it is possible to turn on and off UEFI capsule support from within the BIOS. This functionality can also be adjusted from within the OS by fwupd. This requires compiling with libsmbios support.
When fwupd has been compiled with this support you will be able to enable UEFI
support on the device by using the unlock
command.
Custom EFI System Partition
Since version 1.1.0 fwupd will autodetect the ESP when it is mounted on
/boot/efi
, /boot
, or /efi
. A custom EFI system partition location can be
used by modifying OverrideESPMountPoint in /etc/fwupd/uefi_capsule.conf
.
Setting an invalid directory will disable the fwupd plugin.
External Interface Access
This plugin requires:
- read/write access to the EFI system partition.
- read access to
/sys/firmware/efi/esrt/
- read access to
/sys/firmware/efi/fw_platform_size
- read/write access to
/sys/firmware/efi/efivars