[U-Boot-Users] Value of CFG_PCI_MEMBASE

[Stefan Roese]

On Wednesday 11 June 2008, Sachin Rane wrote:
> In the 'include/configs/ocotea.h" file:
> 8<-------------------------------------------------------------------------
>----------------------------
>
> #define CFG_PCI_MEMBASE     0x80000000      /* mapped pci memory        */

This is the virtual address.

> 8<-------------------------------------------------------------------------
>----------------------------
>
> But the Memory map of the Ocotea board (PPC440GX® Evaluation Board User's
> Manual) has mentioned about the PCI memory  as: Start Address (32 Bit) -
> 9000 0000
> End Address (32 Bit) - 9FFF FFFF
> Start Address (36 Bit) - 3 0000 0000
> End Address (36 Bit) - 3 0FFF FFFF
> Size - 256MB 256 MB

The users manual referrs to the physical (36bit) address.

> I am not clear about the logic behind the value assigned to CFG_PCI_MEMBASE
>    i.e. 0x80000000

The mapping between virtual and physical address is done via the MMU. I 
suggest you take a look at the init.S file in the board directory. This 
should make it clear.

Best regards,
Stefan

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