Calling PnP bios routines like get device node from x86_84 arch

Calling PnP bios routines like get device node from x86_84 arch

[PnP driver]

Hi,    
      I am very new to linux kernel driver development. I need to develop a 
driver for calling  BIOS routines like get device node. I could  call  it
in i386 architecture using the PnP driver. 
     But in x86_64 arch I couldn't see any support. Even I tried to
implement it similar to the i386. But there is no API get_cpu_gdt_table().
Is there any other way to get the cpu_gdt_table? or any other way to 
call the BIOS routines.

    Please help me on this.

-mkr



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Re: Calling PnP bios routines like get device node from x86_84 arch

[Alan Cox]

On Mon, 10 Sep 2007 08:06:20 -0700 (PDT)
PnP driver <mkrameshid@gmail.com> wrote:

> 
> Hi,    
>       I am very new to linux kernel driver development. I need to develop a 
> driver for calling  BIOS routines like get device node. I could  call  it
> in i386 architecture using the PnP driver. 

We use ACPI on AMD64 so you should be parsing the ACPI tables not trying
to rely on legacy interfaces which if I rememeber the spec rightly aren't
even guaranteed safe to call when ACPI is active.

What are you actually trying to achieve.

>      But in x86_64 arch I couldn't see any support. Even I tried to
> implement it similar to the i386. But there is no API get_cpu_gdt_table().
> Is there any other way to get the cpu_gdt_table? or any other way to 
> call the BIOS routines.

Assuming you even have a BIOS - you may have EFI underlying or
Linuxbios or be a virtual machine.

Re: Calling PnP bios routines like get device node from x86_84 arch

[Alan Cox]

> Actually I want to call the BIOS run time functions as per the 
> PNPBIOSSpecification-v1.0a (attached).

We use ACPI for x86_64, which means you need to use the ACPI methods not
the PnPBIOS ones. PnPBIOS isn't valid when ACPI is in use.

Alan

Re: Calling PnP bios routines like get device node from x86_84 arch

[Alan Cox]

On Tue, 11 Sep 2007 21:18:53 +0530
mkrameshid <mkrameshid@gmail.com> wrote:

> Can I call the BIOS function using ACPI . I didn't work on it.
> If I asked a silly question please for give me. I am very new to this.

ACPI replaces the BIOS functions you are trying to use. You *can't* use
those BIOS functions. Not only is there no code for it but it isn't valid
to do so if the operating system is using ACPI.

Instead ACPI provides all the needed device enumerations by its own
method.

Re: Calling PnP bios routines like get device node from x86_84 arch

[mkrameshid]

[-- Attachment #1: Type: text/plain, Size: 1800 bytes --]

Hi Alan,
Thanks for your quick reply.

Actually I want to call the BIOS run time functions as per the 
PNPBIOSSpecification-v1.0a (attached).
Specifically I want to call the function no 0x0 to 0x03. I have 
Dual-Core AMD Opteron(tm) Processor 2216 and AMI BIOS with the pnp bios 
support.
So I could call this functions using the default PnP driver which comes 
along with the (API: call_pnp_bios()) i386 architecture. This driver is 
only available for i386. But not for x86_64.

So I am trying to implement a driver similar to this for x86_64 arch. 
But I couldn't .
Because there is need for get_cpu_gdt_table() which is not available in 
x86_64.
And also some inline asm needs to be totally modify for x86_64. For this

How can I achive this ? Is there any other alternate idea there instead 
of pnp driver?

Please help on this.

-mkr


Alan Cox wrote:
> On Mon, 10 Sep 2007 08:06:20 -0700 (PDT)
> PnP driver <mkrameshid@gmail.com> wrote:
>
>   
>> Hi,    
>>       I am very new to linux kernel driver development. I need to develop a 
>> driver for calling  BIOS routines like get device node. I could  call  it
>> in i386 architecture using the PnP driver. 
>>     
>
> We use ACPI on AMD64 so you should be parsing the ACPI tables not trying
> to rely on legacy interfaces which if I rememeber the spec rightly aren't
> even guaranteed safe to call when ACPI is active.
>
> What are you actually trying to achieve.
>
>   
>>      But in x86_64 arch I couldn't see any support. Even I tried to
>> implement it similar to the i386. But there is no API get_cpu_gdt_table().
>> Is there any other way to get the cpu_gdt_table? or any other way to 
>> call the BIOS routines.
>>     
>
> Assuming you even have a BIOS - you may have EFI underlying or
> Linuxbios or be a virtual machine.
>
>   


[-- Attachment #2: PNPBIOSSpecification-v1.0a.pdf --]
[-- Type: application/pdf, Size: 198965 bytes --]

Re: Calling PnP bios routines like get device node from x86_84 arch

[mkrameshid]

Thanks for the reply. I will try ACPI and let you know the result.

-mkr
Alan Cox wrote:
>> Actually I want to call the BIOS run time functions as per the 
>> PNPBIOSSpecification-v1.0a (attached).
>>     
>
> We use ACPI for x86_64, which means you need to use the ACPI methods not
> the PnPBIOS ones. PnPBIOS isn't valid when ACPI is in use.
>
> Alan
>
>   

Re: Calling PnP bios routines like get device node from x86_84 arch

[mkrameshid]

Can I call the BIOS function using ACPI . I didn't work on it.
If I asked a silly question please for give me. I am very new to this.

-MKR
Alan Cox wrote:
>> Actually I want to call the BIOS run time functions as per the 
>> PNPBIOSSpecification-v1.0a (attached).
>>     
>
> We use ACPI for x86_64, which means you need to use the ACPI methods not
> the PnPBIOS ones. PnPBIOS isn't valid when ACPI is in use.
>
> Alan
>
>   

Re: Calling PnP bios routines like get device node from x86_64 arch

[mkrameshid]

[-- Attachment #1: Type: text/plain, Size: 749 bytes --]

Hi Alan,

To be specific I want to call the function 0x60 ,0x61 and few more 
specified in the BBS specification (attached). These functions or alive 
in 16 bit mode (0xf000 segment)
We can call this functions in i386 using the pnpbios driver 
(bioscalls.c). I must call this functions to change the boot order and 
reboot from linux x86_64 using my driver.
I have seen in some forum that we can off the ACPI during the linux boot.

Can you help on this?

-mkr
Alan Cox wrote:
>> Actually I want to call the BIOS run time functions as per the 
>> PNPBIOSSpecification-v1.0a (attached).
>>     
>
> We use ACPI for x86_64, which means you need to use the ACPI methods not
> the PnPBIOS ones. PnPBIOS isn't valid when ACPI is in use.
>
> Alan
>
>   


[-- Attachment #2: specsbbs101.pdf --]
[-- Type: application/pdf, Size: 183180 bytes --]

Re: Calling PnP bios routines like get device node from x86_84 arch

[mkrameshid]

Hi Alan,

To be specific I want to call the function 0x60 ,0x61 and few more 
specified in the BBS specification (attached). These functions or alive 
in 16 bit mode (0xf000 segment)
We can call this functions in i386 using the pnpbios driver 
(bioscalls.c). I must call this functions to change the boot order and 
reboot from linux x86_64 using my driver.
I have seen in some forum that we can off the ACPI during the linux boot.

Can you help on this?

-mkr
Alan Cox wrote:
>> Actually I want to call the BIOS run time functions as per the 
>> PNPBIOSSpecification-v1.0a (attached).
>>     
>
> We use ACPI for x86_64, which means you need to use the ACPI methods not
> the PnPBIOS ones. PnPBIOS isn't valid when ACPI is in use.
>
> Alan
>
>