Hi Ard. The FACS does expose the "GlobalLock" field. I'm not aware of anything that uses it right now, but it might conceivably break somebody's board driver.
Evan
-----Original Message----- From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org] Sent: 31 March 2016 11:29 To: linaro-uefi@lists.linaro.org; leif.lindholm@linaro.org Cc: ryan.harkin@linaro.org; graeme.gregory@linaro.org; Evan Lloyd; Ard Biesheuvel Subject: [PATCH] Platforms/Juno: drop FACS table
The FACS table does not expose anything meaningful on AArch64, and since the Tianocore ACPI table handling code insists on locating FACS below 4 GB, which may fail since since AArch64 platforms may not have any system RAM below 4 GB to begin with.
The reason for this behavior is to ensure that a 32-bit PEI can access the FACS table on an otherwise 64-bit system, but this is a concern that does not apply to AArch64, since PEI always runs in 64-bit mode in that case. The PI spec currently does not provide any means for PEI to convey its bitness or how much system RAM it can access, so a permanent fix requires a spec update first.
So simply remove the FACS table until the PIWG clarifies the spec in this regard.
Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org
Platforms/ARM/Juno/AcpiTables/AcpiTables.inf | 1 - Platforms/ARM/Juno/AcpiTables/Facs.aslc | 62 ---------------------------- 2 files changed, 63 deletions(-) delete mode 100644 Platforms/ARM/Juno/AcpiTables/Facs.aslc
diff --git a/Platforms/ARM/Juno/AcpiTables/AcpiTables.inf b/Platforms/ARM/Juno/AcpiTables/AcpiTables.inf index 3159d7d37c4a..039cff0a743a 100644 --- a/Platforms/ARM/Juno/AcpiTables/AcpiTables.inf +++ b/Platforms/ARM/Juno/AcpiTables/AcpiTables.inf @@ -25,7 +25,6 @@ Dsdt.asl Dbg2.asl Spcr.asl
- Facs.aslc Fadt.aslc Gtdt.aslc Madt.aslc
diff --git a/Platforms/ARM/Juno/AcpiTables/Facs.aslc b/Platforms/ARM/Juno/AcpiTables/Facs.aslc deleted file mode 100644 index 137ead77c199..000000000000 --- a/Platforms/ARM/Juno/AcpiTables/Facs.aslc +++ /dev/null @@ -1,62 +0,0 @@ -/** @file -* Firmware ACPI Control Structure (FACS) -* -* Copyright (c) 2012 - 2014, ARM Limited. All rights reserved. -* -* This program and the accompanying materials -* are licensed and made available under the terms and conditions of the BSD License -* which accompanies this distribution. The full text of the license may be found at -* http://opensource.org/licenses/bsd-license.php -* -* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, -* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. -* -**/
-#include <IndustryStandard/Acpi.h>
-EFI_ACPI_5_0_FIRMWARE_ACPI_CONTROL_STRUCTURE Facs = {
- EFI_ACPI_5_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE, //
UINT32 Signature
- sizeof (EFI_ACPI_5_0_FIRMWARE_ACPI_CONTROL_STRUCTURE), // UINT32
Length
- 0xA152, // UINT32 HardwareSignature
- 0, // UINT32 FirmwareWakingVector
- 0, // UINT32 GlobalLock
- 0, // UINT32 Flags
- 0, // UINT64 XFirmwareWakingVector
- EFI_ACPI_5_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_VERSION, // UINT8
Version;
- { EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved0[0]
EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved0[1]EFI_ACPI_RESERVED_BYTE }, // UINT8 Reserved0[2]- 0, // UINT32 OspmFlags "Platform firmware
must
// initialize this field to zero."- { EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[0]
EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[1]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[2]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[3]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[4]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[5]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[6]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[7]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[8]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[9]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[10]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[11]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[12]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[13]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[14]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[15]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[16]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[17]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[18]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[19]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[20]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[21]EFI_ACPI_RESERVED_BYTE, // UINT8 Reserved1[22]EFI_ACPI_RESERVED_BYTE }, // UINT8 Reserved1[23]-};
-// -// Reference the table being generated to prevent the optimizer from removing the -// data structure from the executable -//
-VOID* CONST ReferenceAcpiTable = &Facs;
2.5.0
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