[U-Boot] CONFIG_MP affects ability to erase upper portions of flash on 8572

[Kumar Gala]

On Feb 5, 2009, at 1:16 PM, Scott Coulter wrote:

>
> Hi everyone,
>
> I just wanted to share something that I discovered with our 8572-based
> board.  The board's 4Mbyte flash is mapped starting at address
> 0xFFC00000.  When moving to U-boot v2008-10, I discovered that I had
> lost the ability to erase the entire flash (in order to update the
> U-boot binary).  After the erase operation, the flash device would
> contain the erased value, 0xFF, up to the address 0xFFFFF000 with  
> non-FF
> data after that point.  After some investigation, it appears that
> defining the macro CONFIG_MP was causing the issue.  With CONFIG_MP  
> not
> defined, the entire upper portion of flash could be verified as  
> erased.
> My guess is that it has something to do with the start page for the
> secondary processor.  Ultimately, the solution for me was to move the
> flash from 0xFFC00000 to 0xEFC00000 and all was well with CONFIG_MP
> defined.
>
> Scott

This is correct.  As the only 8572 board that exists in the u-boot  
tree is for the Freescale MPC8572DS I didn't query anyone else on  
possible impact of the change.

- k