efivar: Add patch to support runtime variable persistence with file-based storage #1311
Conversation
codeshravan
requested review from
lumag,
ndechesne,
ricardosalveti,
sbanerjee-quic and
vkraleti
as code owners
This patch adds support for persisting EFI variable changes on embedded boards that store variables in a file on the ESP partition rather than in dedicated hardware storage. Many embedded boards lack secure hardware storage (like RPMB) for EFI variables and instead store them in a file on the ESP. When using systemd-boot with file-based variable storage, runtime variable changes are lost on reboot since they only exist in memory. The upstream patch (pr-282.patch) implements automatic persistence by: - Detecting RTStorageVolatile and VarToFile EFI variables - Automatically writing variable changes back to the ESP file - Ensuring EFI variable modifications survive reboots This enables proper support for: - systemd-boot operations that rely on SetVariable at runtime - Boot loader variables (LoaderEntryDefault, LoaderEntryOneShot, etc.) - UEFI capsule updates that modify variables - Any runtime EFI variable changes that need to persist The patch is currently pending upstream review. Upstream-Status: Pending Signed-off-by: Shravan Kumar <shrkum@qti.qualcomm.com>
codeshravan
force-pushed
the
meta-qcom-patches
branch
from
14e53fd to
bc5b964
Compare
| Date: Wed, 18 Jun 2025 22:37:04 +0300 | ||
| Subject: [PATCH] efivarfs: Update a file variable store On SetVariable RT | ||
|
|
||
| Upstream-Status: Pending |
There was a problem hiding this comment.
The tags should be at the end of the message. Also please replace Pending with a proper one.
There was a problem hiding this comment.
In this case the upstream status is backport
Upstream-Status: Backport [https://github.com/rhboot/efivar/commit/68daa04654acbe1bbaa17ebfc23c371b39e69c6b]
| @@ -0,0 +1,2 @@ | |||
| FILESEXTRAPATHS:prepend:qcom := "${THISDIR}/${PN}:" | |||
| SRC_URI:append:qcom = " file://pr-282.patch " | |||
There was a problem hiding this comment.
I would prefer if this goes to OE-Core, there is nothing Qualcomm-specific in it. If it is rejected there, we will take it into this layer.
There was a problem hiding this comment.
@codeshravan the pr is merged in upstream efivars repo.
I have created an issue enquiring about v40 release for efivars.
Once maintainer responds we can decide either to bump oe-core efivars to v40 or otherwise backport.
There was a problem hiding this comment.
@sbanerjee-quic @lumag based upon reply on issue:rhboot/efivar#291 we will take it forward
|
Raised PR on oe-core:openembedded/openembedded-core#111 |
Why? Have you read the readme? I don't think so. See https://github.com/openembedded/openembedded-core/blob/master/README.OE-Core.md#contributing |
|
@lumag I realized it later, I have sent the patch through email, and close the pull request on email. |
5 participants
This patch adds support for persisting EFI variable changes on embedded boards that store variables in a file on the ESP partition rather than in dedicated hardware storage.
Many embedded boards lack secure hardware storage (like RPMB) for EFI variables and instead store them in a file on the ESP. When using systemd-boot with file-based variable storage, runtime variable changes are lost on reboot since they only exist in memory.
The upstream patch (pr-282.patch) implements automatic persistence by:
This enables proper support for:
The patch is currently pending upstream review.
Upstream-Status: Pending