-
Notifications
You must be signed in to change notification settings - Fork 37
EBBR Notes 2024.06.17
Vincent Stehlé edited this page Jun 18, 2024
·
2 revisions
- Heinrich Schuchardt (Canonical)
- Michal Simek (AMD)
- Ilias Apalodimas (Linaro)
- Etienne Carrière (STMicroelectronics)
- Jon Humphreys (TI)
- Vincent Stehlé (Arm)
- No agenda for today.
- We could discuss in-flight pull requests #108 and #119 (and also #129) if interested, but we will not approve them.
- Discussions around the pull requests
- Other impromptu discussions
- UEFI Variables in RAM, GUID in Capsule (and GPT)
- Pull #108: Recommend smbios
- Heinrich has reviewed; suggest to mention what is mandatory.
- Ilias: folks at Linaro are working on implementing all mandatory tables and structures in U-Boot. At least require something. SMBIOS vendor string is used for quirks in EFI stub, too.
- Pull #119: Require authenticated FMP firmware updates
- Dependable boot thinking about introducing authenticated "signalling" capsules for A/B update.
- "Fold" acceptance in authenticated capsule.
- Unauthenticated capsules will be deprecated but supported for a while.
- Ilias: wording is fine. Point to "read the docs" for the link.
- Jon wants to demonstrate with development keys on EVM before we require.
-
Michal: some companies have a policy to never have a (private) key inside a repo.
- TI has dummy keys in the repo today.
- U-Boot could generate the keys on-the-flight during build, when not supplied by a config.
- Would not work to authenticate a capsule, which must be signed by a key, corresponding to a previous version.
- Dependable boot thinking about introducing authenticated "signalling" capsules for A/B update.
- Pull #129: Deprecate spin tables
- Qemu has no EL3, but emulates PSCI -> not blocking.
- UEFI Variables in RAM
- Userspace must copy to persist the variables (
efivar
RedHat package). -
Javier from Ilias' team put a pull request in flight for
efivar
.-
RTStorageVolatile
: EFI Variable with the path to file relative to ESP -
VarToFile
: EFI Variable containing all the (other) EFI Variables, which must be copied to persist
-
- No problem for GRUB before
ExitBootServices()
. - Not clear if
efivar
is in Debian netboot installer for example. Ilias: they might useefibootmgr
. To be confirmed.
- Userspace must copy to persist the variables (
- GUID in Capsule
- One specific GUID per board, per firmware (when several firmwares; ESRT entries).
- Currently in U-Boot, this GUID is tied to the GUID used in the GPT partition type for the FIP.
- Single GUID in U-Boot for all STM32MP1 systems.
- GUID hardcoded in U-Boot header file is not convenient to address systems from multiple vendors.
-
Michal: asked to blacklist GUIDs at LVFS to make sure folks do not go into production with those GUIDs by mistake. Also, GUIDs generated out of compatible strings of Linux are an alternative.
- Ilias: patch to derive GUIDs during build with salt + system compatible string
- https://github.com/ARM-software/ebbr/pull/108
- https://github.com/ARM-software/ebbr/pull/119
- https://github.com/ARM-software/ebbr/pull/129
- https://github.com/rhboot/efivar/pull/267
- https://github.com/ARM-software/ebbr/pull/108
- https://gitlab.com/Linaro/trustedsubstrate/mbfw
- https://mbfw.readthedocs.io/en/latest/
- https://lore.kernel.org/u-boot/[email protected]/