[U-Boot-Users] TEXT_BASE

[Wolfgang Denk]

[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
Linux.

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
image.

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
TEXT_BASE.

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
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