[U-Boot-Users] TEXT_BASE question

Wolfgang Denk wd at denx.de
Wed Jun 23 23:45:03 CEST 2004


In message <BAY2-F23dBdsnvUFcxT00007dc2 at hotmail.com> you wrote:
> 
> My problem is that on my board the address space from FFF80000 to FFFFFFFF 
> is reserved for a special purpose, so I can't put the u-boot.bin at 

This is not possible. For example, the IBM  4xx  processor  hat  it's
reset vector at 0xFFFFFFFC, so the last 4 bytes in your address space
cannot  be  "reserved  for  a  special purpose" (except this "special
purpose" is another boot loader).

> 1. If I use TEXT_BASE = FFFE0000 and simply put the u-boot.bin generated to 
> FFF00000, will it mess up the addressing in the u-boot?

Yes,. of course. Why do you think you  have  to  ask  this  question?
Isn't this obvious?

> 2. If the answer for 1 is yes, how can I move up the end of flash to 
> FFF80000 so that the u-boot.bin will fill from FFF00000 to FFF80000 instead 
> of from FFF00000 to FFFFFFFF?

You cannot. At least a branch instruction must be paced at the  reset
vector,  which  is  0xFFFFFFFC,  which  is the end of your "reserved"
area.


Please redefine your requirements.

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
Men will always be men -- no matter where they are.
	-- Harry Mudd, "Mudd's Women", stardate 1329.8




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