[U-Boot-Users] TEXT_BASE

Wolfgang Denk wd at denx.de
Tue Feb 4 23:28:31 CET 2003

[Let's keep the list Cc:ed or others  will  ask  the  same  questions
again later. Well, they will anyhow :-( ]

In message <8C12DADD-388E-11D7-8C12-00039390D626 at pepper.com> you wrote:
> I am still a bit confused.  Should I set TEXT_BASE to 0x0000000 because 
> that is where physical flash is located? or somewhere else.

This depends. I don't  know  which  architecture  or  board  you  are
talking  about.  On  PowerPC  for  example, you will need to have RAM
mapped to physical address 0x0000 - at least if you ever want to  run

The thing is that it is _you_ who defines the physical  address  map,
and  who programs it with the memory controller of your board. In the
resulting final mapping, TEXT_BASE is the start address of the U-Boot

Let's stick with PPCBoot: after reset, a special temporary mapping is
in place, which will always access memory using /CS0. Note that  this
temporary  situation  has  nothing  to  do with the value defined for

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
You know that feeling when you're leaning back  on  a  stool  and  it
starts to tip over? Well, that's how I feel all the time.
- Steven Wright

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