* [PATCH RESEND] Documentation: admin-guide: fix a doc for efi_no_storage_paranoia the "5KB" instead of the "50%"
@ 2026-07-10 6:22 Koki Iwata
0 siblings, 0 replies; only message in thread
From: Koki Iwata @ 2026-07-10 6:22 UTC (permalink / raw)
To: Jonathan Corbet, Ard Biesheuvel
Cc: Shuah Khan, Matthew Garrett, Andrew Morton, Borislav Petkov,
Randy Dunlap, Thomas Gleixner, Feng Tang, Dapeng Mi, Marco Elver,
Jakub Kicinski, Eric Biggers, Li RongQing, Paul E . McKenney,
Matt Fleming, linux-doc, linux-efi, linux-kernel, iwata.koki
From: Iwata Koki <iwata.koki@fujitsu.com>
The documentation for 'efi_no_storage_paranoia' incorrectly states
the kernel cannot use "more than 50%" of the EFI variable storage.
This percentage-based explanation has been outdated since commit
f8b8404337de ("Modify UEFI anti-bricking code") introduced a fixed 5KB
minimum reserve threshold (EFI_MIN_RESERVE) in
arch/x86/platform/efi/quirks.c. At that time, the documentation was not
updated to reflect this change.
Update the documentation to reflect the "5KB" instead of the "50%".
Fixes: f8b8404337de ("Modify UEFI anti-bricking code")
Signed-off-by: Koki Iwata <iwata.koki@fujitsu.com>
---
Documentation/admin-guide/kernel-parameters.txt | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index b5493a7f8f22..3f75969a679b 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1614,10 +1614,17 @@ Kernel parameters
on all PCI bridges while in the EFI boot stub
efi_no_storage_paranoia [EFI,X86,EARLY]
- Using this parameter you can use more than 50% of
- your efi variable storage. Use this parameter only if
- you are really sure that your UEFI does sane gc and
- fulfills the spec otherwise your board may brick.
+ The kernel reserves 5KB of EFI variable storage for
+ safety, because some UEFI implementation may fail to
+ boot if there's insufficient space in the EFI variable
+ storage.
+
+ Using this parameter, you can use the 5KB reservation
+ in the EFI variable storage.
+
+ However, Use this parameter only if you are really
+ sure that your UEFI does sane gc and fulfills the spec
+ otherwise your board may brick.
efivar_ssdt= [EFI; X86] Name of an EFI variable that contains an SSDT
that is to be dynamically loaded by Linux. If there are
--
2.52.0
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2026-07-10 6:24 UTC | newest]
Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-07-10 6:22 [PATCH RESEND] Documentation: admin-guide: fix a doc for efi_no_storage_paranoia the "5KB" instead of the "50%" Koki Iwata
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox