Re: [ECOS] building for flash

[sensitron medical <sensitronnet at yahoo dot com>]

--- Laurent GONZALEZ <laurent.gonzalez@silicomp.fr>
wrote:
> 
> > Recall that the
> > AT91 resets with ROM located at 0 until remap.
> After
> > remap, I am locating it at 0x01000000.
> > 
> > If I change my rom origin to 0, i.e.:
> > 
> >     rom  : ORIGIN = 0x00000000, LENGTH = 0x200000
> > 
> > then I have a conflict with ram/sram which are
> also at
> > 0. Catch-22.
> > 
> > What I need to do is burn my code (.text and
> .data)
> > into flash at pre-remap address 0 (post-remap
> > 0x01000000), and allow the code to access my .bss
> at
> > post-remap 0, but I don't know how.
> No needs to do anything, the early startup of the
> HAL should take care of the remap command (see
> include/hal_platform_setup.h).
> 

I'm pretty sure that it is not that simple. True, HAL
takes care of *executing* the remap command, but the
problem is that after a remap, the linker sections are
going to be mixed up. Pre- and post-remap references
to the exact same section, .data, for example, are
going to have 2 different values. So if a section is
referenced at runtime prior to remap, the pre-remap
address needs to be used in the linker section
definition. But, for a section that is referenced
after remap, the post-remap address needs to be used.
When I craft my linker script, how am I supposed to
know which address, pre- or post-, to use for a given section?

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