Re: PCI address space

[indira <indira@xxxxxxxxxx>]

thanks saroj,

I  am bit confused.


1) The PCI conf space will contain registers like vendor ID,device ID ..... 
will vendor doesnot provide this.

2) so inside a PCI peripheral we have this PCI conf space .Is it that I am 
telling PCI subsystem that  to allocate some address space for the 
device.If it is so then we have a conf register like Interrupt pin register 
and interrupt line register if we fill this then we tell PCI subsystem to 
route our interrupt on this line using interrupt controller.


3)If we doesnot provide the base address registre value then is it that PCI 
subsystem will provide the address for the PCI device in the  system memory.

4) Please tell me the functionality of pci subsystem as I am  beginner in 
this area.


thanks
indiraa







At 03:54 PM 4/19/05, you wrote:


> On 4/15/05, indira <<mailto:indira@xxxxxxxxxx>indira@xxxxxxxxxx> wrote:
> > Dear all,
> >
> > I studied that every PCI peripheral has got 3 address spaces : 2 only
>
>
>
> > 1) Memory
> > 2)I/O
>
>
>
> > 3)PCI configuration space is for PCI devices to give informastion to PCI 
> > subsystem
>
>
>
> > . Is it that PCI configuration space is
> > within the PCI device where configuration registers are implemented? yes
> >
> > when linux system boots,
>
> PCI BIOS
> > it detects PCI devices and will reads this
> > configuration space and creates memory  for the device in the PCI memory
> > address space or in PCI  I/O address space.
> >
> > will the system memory has this  PCI related address spaces
>
>
>
> >  and also will
> > the linux kernel map the configuration  registers  into its PCI subsystem 
> > space
>
>
>
> > related
> > space.
>
>
>
> > How it will maintain the device related information. see pci_dev structure
> >
> > I read that some configuration registers are filled by vendor and the
>
>
>
> > others like base address register s filling is optional. Vendor cant 
> > hardware this. The value will be populated by the PCI subsystem depnidne 
> > on the memory model choosen duriong compilation.
>
>
>
> > Is it that if not filled the linux kernel will give the address and 
> > copies it to device
> > configuration registers using kernel functions (pci_write_config)? NO
>
> the job is done by PCI Subsystem and not some vendor
>
> > Please help me regarding this as I am working on a target board  where the
> > pci bus I am using  to interact with the pci devices.
> >
> > Thanks,
> > indiraa.
> >
> > --
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