[U-Boot-Users] u-boot on top of another bootloader

[Wolfgang Denk]

In message <20040622013446.79298.qmail at web20730.mail.yahoo.com> you wrote:
> 
> Can u-boot run on top of another bootloader? The board I'm working on has a
> proprietary boot loader. I cannot totally abandon this bootloader because
> the vendor is unwilling to disclose some critical details of the board. So
> I'm thinking of putting u-boot on top of it. Is this idea feasible?

It is possible. Basicly the same modifications need to be  made  like
when attempting to boot from RAM.

> The original boot loader is at 0xFFF00000. One thing I need to do is to
> move the u-boot location to somewhere else. AFAIK u-boot usually locates at
> 0xFFF00000. What feature of a board decides the address of the first

This is not correct. It may be true on some boards, but is not a general rule.

> instruction?

The first instruction  is  determined  by  your  processor  and  it's
configuration,  i. e. from where it fetches the first insruction when
waking  up  out  of  reset.  Common  addresses  are  0x0000,  0x0100,
0xFFF00100, 0xFFFFFFFC, etc.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
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