[U-Boot-Users] Issue regarding entry point address

[Wolfgang Denk]

In message <1126884419.91a96afcS3092131 at student.rmit.edu.au> you wrote:
>
> >>Download address and load address must differt at by least the  size
> >> of the uncompressed kernel size.


> The difference between the compressed and uncompressed image is
> 40 bytes. So i tried to load the image at 0xa0800000 and tried

You must be joking. If your compressed image is  750  KiB,  then  the
uncompressed  image  will  be  around  2  MiB. Which means that loadt
address and download address mut be at least 2  MB  apart  from  each
other.

> to give entry point address as 0xa0800040 but then i get
> BAD MAGIC ERROR.

I really don't know what you expected.

> So how do i look up for the proper load address and entry point
> address.

You cannot "look it up". You define a memory map for your system. You
configure the Linux kernel according to this memory  map.  You  enter
the  corresponding  values  for  load  address  and  antry point when
running the mkimage tool. Then you add at least 2 MB  (better  a  bit
more)  to  your  load  address  and  use  this as download address in
U-Boot.

> As per the CFG_LOAD_ADDR parameter in /include/configs/pxa255idp.h
> load address should be 0xa0800000

This is a default setting which may or may not be  correct  for  your
board.  Also  note  that  this is the download address, not the "load
address" parameter for mkimage.

> but how do i figure out,what is my entry point address.

By looking at your definition of your kernel's memory map.

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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