[U-Boot] [PATCH 0/2] Make sure 85xx bss doesn't start at 0x0

Wolfgang Denk wd at denx.de
Wed Oct 7 01:07:22 CEST 2009


Dear Peter Tyser,

In message <1254862383.24664.2742.camel at localhost.localdomain> you wrote:
>
> What's the advantage of having the bss not be located next to U-Boot?

One advantage is that we might chose the same address for all boards,
and eventually for all Power processor families.

One disadvantage is that we need to relocate it separately, or we will
have a gap in the RAm memory map which is IMO not acceptable.

> The big disadvantage of picking an arbitrary address for the bss is that
> there's now 1 more magical section of SDRAM that the user needs to know
> shouldn't be used.  I already field enough question from people that

Why should it not be used?  You seem to be pretty fixed on that idea,
which is wrong. No code will ever be written to RAM at list location.

In the current setup, we don't write any code to RAM at 0x0 either.

> corrupt their exception vectors or stack/malloc pool/u-boot code, I
> don't want to add more bss questions:)

I cannot follow you here.

Best regards,

Wolfgang Denk

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