Files
system76-edk2/ArmVirtPkg/PlatformHasAcpiDtDxe/PlatformHasAcpiDtDxe.c
Laszlo Ersek 110316a995 ArmVirtPkg/PlatformHasAcpiDtDxe: don't expose DT if QEMU provides ACPI
This will let QEMU's "-no-acpi" option exclusively expose DT vs. ACPI to
the guest. Showing both is never needed (it is actually detrimental to the
adoption of standards, such as SBSA / SBBR).

* Without "-no-acpi", the firmware logs (from PlatformHasAcpiDtDxe)

> Found FwCfg @ 0x9020008/0x9020000
> Found FwCfg DMA @ 0x9020010
> InstallProtocolInterface: [EdkiiPlatformHasAcpi] 0

plus the usual messages. Later the guest kernel logs

> [    0.000000] efi:  SMBIOS 3.0=0x13bdb0000  ACPI 2.0=0x138440000
>                      MEMATTR=0x13a675018

before it lists the ACPI tables one by one.

In addition, in the guest, the "/sys/firmware/devicetree/*" shell pattern
matches no files, while the "/sys/firmware/acpi/tables/*" pattern matches
the ACPI tables.

* With "-no-acpi", the firmware logs:

> PlatformHasAcpiDtDxe | Found FwCfg @ 0x9020008/0x9020000
> PlatformHasAcpiDtDxe | Found FwCfg DMA @ 0x9020010
> PlatformHasAcpiDtDxe | InstallProtocolInterface:
> PlatformHasAcpiDtDxe | [EdkiiPlatformHasDeviceTree] 0
> FdtClientDxe         | OnPlatformHasDeviceTree: exposing DTB @
> FdtClientDxe         | 0x13FFBF000 to OS
> ...
> DXE_CORE             | Driver [AcpiTableDxe] was discovered but not
> DXE_CORE             | loaded!!
> DXE_CORE             | Driver [QemuFwCfgAcpiPlatform] was discovered but
> DXE_CORE             | not loaded!!
> ...
> RamDiskDxe           | RamDiskAcpiCheck: Cannot locate the EFI ACPI
> RamDiskDxe           | Table Protocol, unable to publish RAM disks to
> RamDiskDxe           | NFIT.

(BootGraphicsResourceTableDxe's ReadyToBoot callback --
InstallBootGraphicsResourceTable() -- handles the lack of
EFI_ACPI_TABLE_PROTOCOL silently.) Later the guest kernel logs

> [    0.000000] efi:  SMBIOS 3.0=0x13bdb0000  MEMATTR=0x138caa018

In addition, in the guest, the "/sys/firmware/devicetree/*" shell pattern
matches the directory "/sys/firmware/devicetree/base", which contains a
large number of DT nodes, while the "/sys/firmware/acpi/tables/*" pattern
matches no files.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1430262
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2017-03-28 14:18:47 +02:00

87 lines
2.3 KiB
C

/** @file
Decide whether the firmware should expose an ACPI- and/or a Device Tree-based
hardware description to the operating system.
Copyright (c) 2017, Red Hat, Inc.
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 <Guid/PlatformHasAcpi.h>
#include <Guid/PlatformHasDeviceTree.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/QemuFwCfgLib.h>
#include <Library/UefiBootServicesTableLib.h>
EFI_STATUS
EFIAPI
PlatformHasAcpiDt (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
FIRMWARE_CONFIG_ITEM FwCfgItem;
UINTN FwCfgSize;
//
// If we fail to install any of the necessary protocols below, the OS will be
// unbootable anyway (due to lacking hardware description), so tolerate no
// errors here.
//
if (MAX_UINTN == MAX_UINT64 &&
!EFI_ERROR (
QemuFwCfgFindFile (
"etc/table-loader",
&FwCfgItem,
&FwCfgSize
)
)) {
//
// Only make ACPI available on 64-bit systems, and only if QEMU generates
// (a subset of) the ACPI tables.
//
Status = gBS->InstallProtocolInterface (
&ImageHandle,
&gEdkiiPlatformHasAcpiGuid,
EFI_NATIVE_INTERFACE,
NULL
);
if (EFI_ERROR (Status)) {
goto Failed;
}
return Status;
}
//
// Expose the Device Tree otherwise.
//
Status = gBS->InstallProtocolInterface (
&ImageHandle,
&gEdkiiPlatformHasDeviceTreeGuid,
EFI_NATIVE_INTERFACE,
NULL
);
if (EFI_ERROR (Status)) {
goto Failed;
}
return Status;
Failed:
ASSERT_EFI_ERROR (Status);
CpuDeadLoop ();
//
// Keep compilers happy.
//
return Status;
}