[edk2-platform PATCH v1 1/1] Platform/RaspberryPi: Make SetVariable return EFI_UNSUPPORTED at runtime


Sunny Wang
 

The RPi does not support storing UEFI NV variables at runtime. For now,
gRT->SetVariable at runtime returns EFI_OUT_OF_RESOURCES which is not a
proper error and would cause FWTS failures. Therefore, this patch is
to make gRT->SetVariable at runtime return EFI_UNSUPPORTED.

For more information, please check the issues below:
-https://github.com/pftf/RPi4/issues/6
-https://github.com/pftf/RPi4/issues/93
-https://github.com/pftf/RPi4/issues/163

I also tested this with the ACS 3.0 FWTS. All the failures
reported in issue 93 and 163 can be fixed by this patch.

Cc: Samer El-Haj-Mahmoud <samer.el-haj-mahmoud@arm.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Pete Batard <pete@akeo.ie>
Cc: Leif Lindholm <leif@nuviainc.com>

Signed-off-by: Sunny Wang <sunny.wang@arm.com>
---
.../Drivers/VarBlockServiceDxe/VarBlockService.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/Platform/RaspberryPi/Drivers/VarBlockServiceDxe/VarBlockServ=
ice.c b/Platform/RaspberryPi/Drivers/VarBlockServiceDxe/VarBlockService.c
index 572309439a..16d4d4f178 100644
--- a/Platform/RaspberryPi/Drivers/VarBlockServiceDxe/VarBlockService.c
+++ b/Platform/RaspberryPi/Drivers/VarBlockServiceDxe/VarBlockService.c
@@ -2,6 +2,7 @@
*
* Copyright (c) 2018, Andrei Warkentin <andrey.warkentin@gmail.com>
* Copyright (c) 2006-2014, Intel Corporation. All rights reserved.
+ * Copyright (c) 2021, ARM Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-2-Clause-Patent
*
@@ -596,6 +597,7 @@ FvbProtocolWrite (
EFI_DEVICE_ERROR - The block device is not functioning correctl=
y and
could not be written
EFI_INVALID_PARAMETER - NumBytes or Buffer are NULL
+ EFI_UNSUPPORTED This function is not supported at runtime
=20
--*/
{
@@ -605,6 +607,16 @@ FvbProtocolWrite (
EFI_STATUS Status;
EFI_STATUS ReturnStatus;
=20
+ //
+ // The current variables support relies on modifying RPI_EFI.FD on SD
+ // card, which works fine at boot time. However, at runtime, the SD=20
+ // controller is exposed via ACPI and subsequently owned by the OS.
+ // Therefore, we need to direclty return EFI_UNSUPPORTED.
+ //
+ if (EfiAtRuntime ()) {
+ return EFI_UNSUPPORTED;
+ }
+
//
// Check for invalid conditions.
//
--=20
2.31.0.windows.1

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