Hi,
EFI_ACPI_TABLE_PROTOCOL is to get ACPI tables while
ACPI_SDT_PROTOCOL is to analyze them.
Wishes,
Sergey
On 31 янв. 2014 г., at 18:29, Yao, Jiewen <jiewen....@intel.com> wrote:
> HI
> UEFI OS loader or OS kernel can get ACPI2.0 RSDP from UEFI configuration
> table via EFI_ACPI_20_TABLE_GUID. See UEFI2.4a spec, page 93.
> Then it can parse all ACPI information, like RSDP->XSDT->FADT->DSDT.
>
> I think you also use this way too.
>
> The limitation of ACPI_SDT_PROTOCOL is that: It is defined in PI spec, and
> not all platform BIOS produce it, as far as I know.
>
> Thank you
> Yao Jiewen
>
> From: Rafael Machado [mailto:rafaelrodrigues.mach...@gmail.com]
> Sent: Friday, January 31, 2014 10:02 PM
> To: Laszlo Ersek
> Cc: edk2-devel
> Subject: Re: [edk2] ACPI Read at UEFI
>
> Thanks for the answer Laszlo.
> I'll thake a look on these information.
>
> Nice to know this question helped you too.
> Thanks
> Rafael R. Machado
>
>
> 2014-01-31 Laszlo Ersek <ler...@redhat.com>:
> On 01/31/14 11:39, Rafael Machado wrote:
> > Hi everyone.
> >
> > I have a question.
> > I need to read some ACPI tables data at UEFI.
> > As far as I could check, the only defined protocols to work with acpi
> > tables at uefi are related to install and unninstall a new table, but
> > how could I do to read a table already defined by the ACPI spec ?
> > For example read the information contained at the Differentiated System
> > Description Table (DSDT).
>
> You can install and uninstall tables with EFI_ACPI_TABLE_PROTOCOL.
> See UEFI 2.4a, 19 Protocols - ACPI Protocols.
>
> Apparently, you can locate and walk tables with EFI_ACPI_SDT_PROTOCOL.
> See Platform Init Vol.5, 9 ACPI System Description Table Protocol.
>
> In edk2, the reference implementation for both of these is provided by
> MdeModulePkg/Universal/Acpi/AcpiTableDxe. EFI_ACPI_SDT_PROTOCOL is only
> installed dependent on
> "gEfiMdeModulePkgTokenSpaceGuid.PcdInstallAcpiSdtProtocol".
>
> OVMF (for example) already builds in the driver, but for now we only use
> the EFI_ACPI_TABLE_PROTOCOL that the driver provides. If you want the
> other protocol too, you likely have to set said PCD to TRUE, in
> OvmfPkg/OvmfPkg*.dsc, under [PcdsFeatureFlag].
>
> Thanks for making me investigate this a little bit, especially
> EFI_ACPI_SDT_PROTOCOL. In OvmfPkg we might want to inspect, at some
> point, the ACPI tables that QEMU exports, and EFI_ACPI_SDT_PROTOCOL
> could be handy to navigate them.
>
> Laszlo
>
> ------------------------------------------------------------------------------
> WatchGuard Dimension instantly turns raw network data into actionable
> security intelligence. It gives you real-time visual feedback on key
> security issues and trends. Skip the complicated setup - simply import
> a virtual appliance and go from zero to informed in seconds.
> http://pubads.g.doubleclick.net/gampad/clk?id=123612991&iu=/4140/ostg.clktrk_______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/edk2-devel
------------------------------------------------------------------------------
WatchGuard Dimension instantly turns raw network data into actionable
security intelligence. It gives you real-time visual feedback on key
security issues and trends. Skip the complicated setup - simply import
a virtual appliance and go from zero to informed in seconds.
http://pubads.g.doubleclick.net/gampad/clk?id=123612991&iu=/4140/ostg.clktrk
_______________________________________________
edk2-devel mailing list
edk2-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/edk2-devel
