Where does the ACPI data in the registry
HLM\HARDWARE\ACPI.… branch comes from?
Is it populated in Windows setup time, or read from the BIOS on every boot?
Does ACPI actually use this data in the runtime?
I’d like to understand what can be impact of this registry data when a disk image is installed on a slightly different machine.
Thanks,
Pavel
> Where does the ACPI data in the registry
HLM\HARDWARE\ACPI.… branch comes from?
From BIOS tables I think. I think NTLDR grabs the ACPI tables from BIOS using
int 15h and adds them to HKLM\HARDWARE which it constructs on boot.
Does ACPI actually use this data in the runtime?
I expect ACPI.SYS uses only this data, without any more int 15h calls. Surely
Jake Oshins can correct me 
I’d like to understand what can be impact of this registry data when a disk
image is installed on a slightly different machine.
This data is volatile and constructed on boot.
–
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
Max is right, except in that INT 15h has nothing to do with it. The only
thing that I’ll add is that some crappy backup programs will save volatile
registry keys and restore them as non-volatile, smashing these keys and
others. Once you’ve done that you’ll probably render your machine
inoperable with a bunch of odd bugs.
“Maxim S. Shatskih” wrote in message
news:xxxxx@ntdev…
>> Where does the ACPI data in the registry
>> HLM\HARDWARE\ACPI.… branch comes from?
>
> From BIOS tables I think. I think NTLDR grabs the ACPI tables from BIOS
> using
> int 15h and adds them to HKLM\HARDWARE which it constructs on boot.
>
>> Does ACPI actually use this data in the runtime?
>
> I expect ACPI.SYS uses only this data, without any more int 15h calls.
> Surely
> Jake Oshins can correct me
>
>> I’d like to understand what can be impact of this registry data when a
>> disk
>>image is installed on a slightly different machine.
>
> This data is volatile and constructed on boot.
>
> –
> Maxim Shatskih, Windows DDK MVP
> StorageCraft Corporation
> xxxxx@storagecraft.com
> http://www.storagecraft.com
>
>
> Max is right, except in that INT 15h has nothing to do with it.
And what are the BIOS’s means to get the ACPI table from it?
–
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
I’m sorry. I don’t quite understand the question. Can you rephrase it?
“Maxim S. Shatskih” wrote in message
news:xxxxx@ntdev…
>> Max is right, except in that INT 15h has nothing to do with it.
>
> And what are the BIOS’s means to get the ACPI table from it?
>
> –
> Maxim Shatskih, Windows DDK MVP
> StorageCraft Corporation
> xxxxx@storagecraft.com
> http://www.storagecraft.com
>
>
How NTLDR extracts the ACPI table from BIOS? I think that BIOS should
provide some interface to do this, and considered int 15h. Is it not so?
–
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
“Jake Oshins” wrote in message
news:xxxxx@ntdev…
> I’m sorry. I don’t quite understand the question. Can you rephrase it?
>
>
> “Maxim S. Shatskih” wrote in message
> news:xxxxx@ntdev…
> >> Max is right, except in that INT 15h has nothing to do with it.
> >
> > And what are the BIOS’s means to get the ACPI table from it?
> >
> > –
> > Maxim Shatskih, Windows DDK MVP
> > StorageCraft Corporation
> > xxxxx@storagecraft.com
> > http://www.storagecraft.com
> >
> >
>
>
>
BIOS does the system initialization and before OS handoff BIOS populated
ACPI and SMBIOS tables in memory , the structure of tables are compiled
with DMTF specification so that Any OS can parse them .
Thanks and Regards
~Neeraj
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Maxim S.
Shatskih
Sent: Monday, January 22, 2007 2:26 PM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] ACPI information in registry
How NTLDR extracts the ACPI table from BIOS? I think that BIOS
should
provide some interface to do this, and considered int 15h. Is it not so?
–
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
“Jake Oshins” wrote in message
news:xxxxx@ntdev…
> I’m sorry. I don’t quite understand the question. Can you rephrase
it?
>
>
> “Maxim S. Shatskih” wrote in message
> news:xxxxx@ntdev…
> >> Max is right, except in that INT 15h has nothing to do with it.
> >
> > And what are the BIOS’s means to get the ACPI table from it?
> >
> > –
> > Maxim Shatskih, Windows DDK MVP
> > StorageCraft Corporation
> > xxxxx@storagecraft.com
> > http://www.storagecraft.com
> >
> >
>
>
>
—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
To unsubscribe, visit the List Server section of OSR Online at
http://www.osronline.com/page.cfm?name=ListServer
> The only
thing that I’ll add is that some crappy backup programs will save volatile
registry keys and restore them as non-volatile, smashing these keys and
others. Once you’ve done that you’ll probably render your machine
inoperable with a bunch of odd bugs.
- Jake Oshins
Jake, this looks very much like my issue.
They put some ghost’ed disk image on their XP machine and odd things suddenly
begin with our PCIe device.
They put another image, and it works well.
So should I look for reg keys that must be volatile but are not?
What else can interfere with PCIe power management?
( Ghost does a full disk image, so it can’t affect volatile keys - but I am not sure
what else they may use to make that image )
Regards,
–PA
The BIOS just leaves a signature in memory. It’s the responsibility of an
OS (or the loader) to scan across the ranges of memory where the signature
might occur. In the case of ACPI, the spec says that the signature should
appear on a 16-byte boundary from 0xE:0000 to 0xF:FFFF or in the Extended
BIOS Data Area.
“Maxim S. Shatskih” wrote in message
news:xxxxx@ntdev…
> How NTLDR extracts the ACPI table from BIOS? I think that BIOS should
> provide some interface to do this, and considered int 15h. Is it not so?
>
> –
> Maxim Shatskih, Windows DDK MVP
> StorageCraft Corporation
> xxxxx@storagecraft.com
> http://www.storagecraft.com
>
> “Jake Oshins” wrote in message
> news:xxxxx@ntdev…
>> I’m sorry. I don’t quite understand the question. Can you rephrase it?
>>
>>
>> “Maxim S. Shatskih” wrote in message
>> news:xxxxx@ntdev…
>> >> Max is right, except in that INT 15h has nothing to do with it.
>> >
>> > And what are the BIOS’s means to get the ACPI table from it?
>> >
>> > –
>> > Maxim Shatskih, Windows DDK MVP
>> > StorageCraft Corporation
>> > xxxxx@storagecraft.com
>> > http://www.storagecraft.com
>> >
>> >
>>
>>
>>
>
>
>
It leave the data also right…
Thanks and Regards
~Neeraj
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Jake Oshins
Sent: Tuesday, January 23, 2007 12:39 AM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] ACPI information in registry
The BIOS just leaves a signature in memory. It’s the responsibility of
an
OS (or the loader) to scan across the ranges of memory where the
signature
might occur. In the case of ACPI, the spec says that the signature
should
appear on a 16-byte boundary from 0xE:0000 to 0xF:FFFF or in the
Extended
BIOS Data Area.
“Maxim S. Shatskih” wrote in message
news:xxxxx@ntdev…
> How NTLDR extracts the ACPI table from BIOS? I think that BIOS
should
> provide some interface to do this, and considered int 15h. Is it not
so?
>
> –
> Maxim Shatskih, Windows DDK MVP
> StorageCraft Corporation
> xxxxx@storagecraft.com
> http://www.storagecraft.com
>
> “Jake Oshins” wrote in message
> news:xxxxx@ntdev…
>> I’m sorry. I don’t quite understand the question. Can you rephrase
it?
>>
>>
>> “Maxim S. Shatskih” wrote in message
>> news:xxxxx@ntdev…
>> >> Max is right, except in that INT 15h has nothing to do with it.
>> >
>> > And what are the BIOS’s means to get the ACPI table from it?
>> >
>> > –
>> > Maxim Shatskih, Windows DDK MVP
>> > StorageCraft Corporation
>> > xxxxx@storagecraft.com
>> > http://www.storagecraft.com
>> >
>> >
>>
>>
>>
>
>
>
—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
To unsubscribe, visit the List Server section of OSR Online at
http://www.osronline.com/page.cfm?name=ListServer