[U-Boot-Users] Value of CFG_PCI_MEMBASE

[Stefan Roese <sr@denx.de>]

On Monday 16 June 2008, Sachin Rane wrote:
> Infact I was looking for the info to create a proper 'tlbentry' in 'init.S'
> As per my understanding the 'tlbentry' is to map 32-bit address to 36-bit
> address.
>
> The 'tlbenry' for the PCI Memory in 'init.S' is :
> tlbentry( CFG_PCI_MEMBASE, SZ_256M, 0x00000000, 3, AC_R|AC_W|SA_G|SA_I )
>
> The 'CFG_PCI_MEMBASE' is set to 0x80000000 in 'ocotea.h'.
>
> My question is how to select the value for 'CFG_PCI_MEMBASE'.
> Can I use any value (say 0x50000000 ) provided it is not overlapping with
> other devices?

Yes. I suggest to start with 0x80000000 since this leaves the first 2 GB for 
SDRAM.

> If we are using Board Memory Map as a reference then the 32-bit address
> 'CFG_PCI_MEMBASE'  used in 'telbentry' should have set to: 0x90000000

Why is this? Which "Board Memory Map" are you referring to?

> I am trying to find out the logic behind the selection of value for the
> variabale 'CFG_PCI_MEMBASE' in: tlbentry( CFG_PCI_MEMBASE, SZ_256M,
> 0x00000000, 3, AC_R|AC_W|SA_G|SA_I )

Whats the problems with using 0x80000000 here?

Best regards,
Stefan

=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: office at denx.de
=====================================================================