[U-Boot-Users] Booting MPC8272ADS from flash base

[Alex Zeffertt]

On Thu, 13 Oct 2005 07:55:36 -0400
Jerry Van Baren <gerald.vanbaren at smiths-aerospace.com> wrote:

> Alex Zeffertt wrote:
> > Hi list,
> > 
> > I would like to boot my MPC8272ADS board from the base of flash
> > memory.  By default the BCSR delivers a fixed HRCW which tells the
> > CPU to boot from 0xff700000.  But there is a jumper on the board
> > which allows you to specify that the CPU should retrieve the HRCW
> > from flash.
> > 
> > In an attempt to get it to boot from 0x0 I tried the following:
> > 
> > 1.	Moved jumper JP9 from "BCSR" to "MEMORY" to tell the CPU to 
> > 	get its HRCW from flash rather than the BCSR.
> > 
> > 2.	Set TEXT_BASE in config.mk to 0x0
> > 
> > 3.	define CFG_HRCW_MASTER in MPC8260ADS.h to be the value
> > normally
> > 	delivered by the BCSR or'd with (HRCW_CIP | HRCW_BMS).  This
> > 	should move the reset vector from 0xfff00100 to 0x100 and
> > 	cause the flash to be mapped from 0x0 to 0x01ffffff.
> > 
> > Unfortunately this didn't work.
> > 
> > Has anybody else managed to get the MPC8272ADS to boot WITHOUT
> > using the BCSR to deliver the HRCW?
> > 
> > Regards,
> > 
> > Alex
> 
> Hi Alex,
> 
> I did this for the PQ2FADS board, which should be very similar to
> the MPC8260ADS board.  Check out the "bootlow" configuration for
> PQ2FADS.
> 
> I cannot give you specific advice, but I would review each and every
> bit in the HRCW (step #3 doesn't sound thorough enough).  Ahhh,
> looking at my patch email (below), the IMMR that your board defaults
> to may not be a happy choice.
> 

Hi Jerry,

Thanks for writing back.  I've had a go with your patch but I still
can't get it to work!  I think I've tried every combination now....

Alex