In general, we should not present two separate (and inevitably different)
hardware descriptions to the OS, in the form of ACPI tables and a device
tree blob. For this reason, we recently added the logic to ArmVirtQemu to
only expose the ACPI 2.0 entry point if no DT binary is being passed, and
vice versa.
However, this is arguably a regression for those who relied on DT
descriptions being available, even if the former behavior can be
restored by passing the -no-acpi switch to QEMU.
So allow a secret handshake with the UEFI Shell, to set a variable that
will result in ACPI to be disabled on subsequent boots even if -no-acpi
was not passed on the QEMU command line.
setvar -nv -bs -guid 50bea1e5-a2c5-46e9-9b3a-59596516b00a ForceNoAcpi =01
To delete the variable and revert to the old situation, simply omit the
value after the =
setvar -nv -bs -guid 50bea1e5-a2c5-46e9-9b3a-59596516b00a ForceNoAcpi =
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
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>
This driver produces the EDKII Platform Has ACPI and Platform Has Device
Tree protocols, exactly matching the current ACPI / DT exposure on QEMU,
according to ARM vs. AARCH64, and (in the latter case) to PcdPureAcpiBoot.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Ard Biesheuvel
Laszlo Ersek