[U-Boot-Users] Can MPC processors boot though the IMMR is at 0x0 (default configuration)?

[Wolfgang Denk]

In message <429091ED.2090202 at web.de> you wrote:
> I'm going to try booting u-boot on a custom MPC875 board.
> It has flash at the boot memory bank (bank 0).
> It has no circuit to pull up pin 7/8 of the MPC data bus at processor
> start, so (the manual says) the IMMR/the internal memory is configured
> to reside at 0x0.
> 
> I think this causes the internal memory to shadow the boot flash, which

Only in this address range.

> should prevent the board from booting. At least the internal memory
> shadows the boot memory bank in the debugger.

So just configure the board for high-boot, i. e. to use 0xFFF00100 as
boot vector.

> So - does someone incidentally know something about MPC default
> configurations and if MPCs can boot though the IMMR is at 0x0?

Yes,it can.

> And if they can't, why the IMMR is at 0x0 by default?

0 is as good a value as any other.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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