[Fw_Os_Forum] possible UEFI vs ACPI documentation disagreement/improvement suggestions

[Kevin Davis]

Rudolf,

It probably isn't obvious to anyone who hasn't lived in the ACPI community forever, but the correct contact is the UEFI Forum.  http://www.uefi.org/contact_us

The ACPI Working Group is the first working group on this page http://www.uefi.org/workinggroups


ACPI Specification Working Group

Abbreviated name of Work Group:  ASWG 

Charter:  The group’s scope is to manage and evolve the definition of the “Advanced Configuration and Power Interface” specification (ACPI Spec). The purpose of the specification is to define flexible and extensible interfaces for system configuration, power management and RAS (Reliability, Availability, Supportability) features useful for systems across all market segments from embedded and ultra-mobile devices to the enterprise servers. ACPI normally includes static tables for platforms to communicate system information to the OS during early boot and a name space with control methods as primary runtime interfaces between platform firmware and operating systems software. 

Work Group Chair:  Mark Doran & Dong Wei 
Company:  Mark: Intel; Dong: HP

Thanks,
Kevin
戴連輝

-----Original Message-----
From: fw_os_forum-bounces at mailman.uefi.org [mailto:fw_os_forum-bounces at mailman.uefi.org] On Behalf Of Rudolf Marek
Sent: Thursday, June 30, 2016 2:02 PM
To: fw_os_forum at mailman.uefi.org
Subject: [Fw_Os_Forum] possible UEFI vs ACPI documentation disagreement/improvement suggestions

Hi all,

No idea if this is correct channel. I'm looking for some kind of contact of responsible entity of ACPI specification. I noticed following:

ACPI specs 6.1

1) Please mark in the "5.2.5.3 RSDP Structure" in a more clear in a way that it is understandable where the ACPI 1.0 RSDP ends. The ACPI 1.0 ends at offset 20, and contains no length field. This seems to be never ending problem. It looks like OVMF has also some issue (I need to investigate that)

Even ACPICA guys had it wrong some time ago
http://bugs.acpica.org/show_bug.cgi?id=1097

2) The ACPI and UEFI specs seems to contradict of when it is safe to retrieve the ACPI RSDP from UEFI

ACPI spec says:

5.2.5.2 Finding the RSDP on UEFI Enabled Systems

The OS loader must retrieve the pointer to the RSDP structure from the EFI System Table *before* assuming platform control via the EFI ExitBootServices interface. See the UEFI Specification for more information.

However UEFI 2.6 says:

4.3 EFI System Table
...

After an operating system has taken control of the platform with a call to ExitBootServices(), only the Hdr, FirmwareVendor, FirmwareRevision, RuntimeServices, NumberOfTableEntries, and ConfigurationTable fields are valid.

So, is the RSDP valid after ExitBootServices or not?

3)  The ACPI specs does not mention this GUID:

#define ACPI_TABLE_GUID \
 {0xeb9d2d30,0x2d88,0x11d3,\
 {0x9a,0x16,0x00,0x90,0x27,0x3f,0xc1,0x4d}}

It looks there are some duplicate names for same ACPI GUIDs, I did not noticed this at first. Perhaps the UEFI specs can make it more clear?

4) I failed to find the contact inside the document for this kind of questions/remarks

Thanks
Rudolf
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