[U-Boot-Users] Stack Size for MPC8xx???

Wolfgang Denk wd at denx.de
Sat Oct 18 22:43:21 CEST 2003

Dear Steven,

in message <3F913F10.2010706 at imc-berlin.de> you wrote:
> does someone know how big the stack is for an MPC8xx based boards?

This is board-dependend - how much RAM do you have?

On MPC8xx the stack grows downward,  so  it  can  become  as  big  as
necessary  as  long  as  it does not colide with the exception vector
table or any data you put into RAM.

> I had this problem:
> I started porting U-Boot to my new AT91RM9200 based board. After doing the flash 
> I have CFG_ENV_SECT_SIZE = 64K and CFG_ENV_SIZE=4K and realized that
> my stack 
> was far to small to save an 64KB flash sector.

This is one of the consequences of the  broken  design  we  inherited
from ARMBoot.

> The funny thing is that I never worried about that issue. And it never se
> ems to 
> be a problem on our MPC8xx based boards...

That's because PPC uses a different memory layout (as  documented  in
the README).

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
There is a time in the tides of men, Which, taken at its flood, leads
on to success. On the other hand, don't count on it.   - T. K. Lawson

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