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

[Jerry Van Baren]

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.

References:
-----------
Gmane archive, includes the patch Wolfgang applied.
<http://search.gmane.org/?query=PATCH%3A+add+low-boot+configuration+to+MPC8260ADS+family+of+boards+&email=&group=&sort=relevance&DEFAULTOP=and&xP=patch.add.low.boot.configuration.mpc8260ads.family.boards.&xFILTERS=Gu-boot---A>

Sourceforge's email list (no attachments):
<http://sourceforge.net/mailarchive/message.php?msg_id=9992822>

Follow-up posting:
<http://article.gmane.org/gmane.comp.boot-loaders.u-boot/17917>

gvb