[U-Boot] Fix for overlapping sections?

[Albert ARIBAUD]

Le 20/04/2011 21:03, Charles Manning a écrit :
> On Tuesday 19 April 2011 11:20:47 Ciummo, Larry (DS-1) wrote:
>> Designation: Non-SSA/Finmeccanica
>>
>> A while back there was a fix for the overlapping section link problem
>> (see below) involving changing some sort of global.  Does anyone have a
>> pointer to the change.  I'm using a fairly old uboot for AMCC
>> Canyonlands/460Ex and can't easily upgrade to a newer uboot build.
>>
>> Thanks
>> Larry
>>
>> eldk/usr/bin/../lib/gcc/powerpc-linux/4.2.2/pic -lgcc -Map u-boot.map -o
>> u-boot
>> /opt/eldk/usr/bin/ppc_4xx-ld: section .bootpg [fffff000 ->  fffff303]
>> overlaps section .data.rel.local [ffffe1d8 ->  fffffebb]
>> /opt/eldk/usr/bin/ppc_4xx-ld: u-boot: section .bootpg lma 0xfffff000
>> overlaps previous sections
>> /opt/eldk/usr/bin/ppc_4xx-ld: u-boot: section .u_boot_cmd lma 0xfffffebc
>> overlaps previous sections
>> make: *** [u-boot] Error 1
>
> Overlapping sections are commonly caused by one of two problems:
> 1) You have set up the memory map in a way that does not give enough space so
> the sections do indeed overlap.
> 2) Your ld script is not handling all the sections being fed to it. This is
> likely if you have switched to  using -ffunction-sections etc.
>
> In the case of (2) you will need to modify your ld script with something like:
> @@ -34,8 +34,8 @@ SECTIONS
>          . = ALIGN(4);
>          .text   :
>          {
> -               arch/arm/cpu/armv7/start.o      (.text)
> -               *(.text)
> +               KEEP(arch/arm/cpu/armv7/start.o (.text*))
> +               *(.text*)
>          }
>
>          . = ALIGN(4);
> @@ -70,7 +70,7 @@ SECTIONS
>
>          .bss __rel_dyn_start (OVERLAY) : {
>                  __bss_start = .;
> -               *(.bss)
> +               *(.bss*)
>                   . = ALIGN(4);
>                  __bss_end__ = .;
>          }

Watch out: these are ARM excerpts. The original problem is on PPC, to 
which these might possibly not apply.

Aside: I understand the stars added because of the -ffunction-section in 
your example, but why the KEEP(), or more specifically, what makes it 
required with -ffunction-section? Unless you assume --gc-sections also?

Amicalement,
-- 
Albert.