Re: [ECOS] Running from Redboot

[Gary Thomas <gary at mlbassoc dot com>]

On Fri, 2003-08-15 at 14:24, Unni Nair wrote:
> When I increased the size of the reserved_for_rom, the
> available ram reported by redboot (start address) was
> changed to reflect the change. 
> 
> Unfortunately the problem I am facing is with the ECOS
> + application linking process, relocating the code to
> be loaded to the end of the reserved_for_rom section
> (which is not where the available ram resides).
> 

You changed the wrong file - change this value in the MLT
files for RAM mode startup.

> Unni
> 
> > Hello Gary:
> > 
> > Unfortunately I do not know how to post a followup
> to
> > your response, hence emailing you directly.
> 
> In that case, why not just send this to the list (and
> maybe
> copy it to me)?
> 
> > 
> > The reserved_for_rom section is empty (I actually
> > modified the adder board code to suit my needs).
> > Apparently redboot is using areas after the
> > reserved_for_room section to store additional
> > sections. These details are not taken into
> > consideration when I recompile for ECOS (default)
> and
> > the linker is generating code located immediately
> > after the reserved_for_rom (empty section). I do not
> > know if the reserved_for_rom section is needed? 
> 
> It is indeed - that's how the .ldi file indicates what
> memory is
> used by RedBoot and what memory can be used by the
> application.
> 
> Looking at the real 'adder' MLT file:
> SECTIONS
> {
>     SECTIONS_BEGIN
>     CYG_LABEL_DEFN(__reserved_vectors) = 0; . =
> CYG_LABEL_DEFN(__reserved_vectors) + 0x3000;
>     CYG_LABEL_DEFN(__reserved_vsr_table) = ALIGN
> (0x10); . = CYG_LABEL_DEFN(__reserved_vsr_table) +
> 0x200;
>     CYG_LABEL_DEFN(__reserved_virtual_table) = ALIGN
> (0x10); . = CYG_LABEL_DEFN(__reserved_virtual_table) +
> 0x100;
>     CYG_LABEL_DEFN(__reserved_for_rom) = ALIGN (0x10);
> . = CYG_LABEL_DEFN(__reserved_for_rom) + 0x3cd00;
>     SECTION_vectors (ram, ALIGN (0x10), LMA_EQ_VMA)
>     SECTION_text (ram, ALIGN (0x4), LMA_EQ_VMA)
>     SECTION_fini (ram, ALIGN (0x4), LMA_EQ_VMA)
>     SECTION_rodata1 (ram, ALIGN (0x8), LMA_EQ_VMA)
>     SECTION_rodata (ram, ALIGN (0x8), LMA_EQ_VMA)
>     SECTION_fixup (ram, ALIGN (0x4), LMA_EQ_VMA)
>     SECTION_gcc_except_table (ram, ALIGN (0x1),
> LMA_EQ_VMA)
>     SECTION_data (ram, ALIGN (0x8), LMA_EQ_VMA)
>     SECTION_sbss (ram, ALIGN (0x4), LMA_EQ_VMA)
>     SECTION_bss (ram, ALIGN (0x10), LMA_EQ_VMA)
>     CYG_LABEL_DEFN(__heap1) = ALIGN (0x8);
>     SECTIONS_END
> }
> 
> If you do the calculations, you'll see that the
> "__reserved_for_rom" segment
> extends up through 0x80000.  If your RedBoot reports
> an address higher than
> this, just change the 0x3cd00 above to an appropriate
> value.  E.g. 0x4cd00
> would start the user applications 
> 
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-- 
Gary Thomas <gary@mlbassoc.com>
MLB Associates


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