Re: microblaze-elf - missing priority for the constructors

[nick clifton <nickc at redhat dot com>]

Hi Christophe,

> I cross-compiled GCC 4.6.3 and binutil 2.22 for microblaze
> and I came into a problem when trying an eCos RTOS based application.
> The constructors table is not sorted by priority, actually the priority
> seem to be gone. I have added this template in the linker script:

Strange - that should not be needed.  The built-in microblaze linker 
script already includes support for sorting constructors:

  % microblaze-elf-ld --verbose
  [...]
 .ctors   :
  {
    /* gcc uses crtbegin.o to find the start of
       the constructors, so we make sure it is
       first.  Because this is a wildcard, it
       doesn't matter if the user does not
       actually link against crtbegin.o; the
       linker won't look for a file to match a
       wildcard.  The wildcard also means that it
       doesn't matter which directory crtbegin.o
       is in.  */
    KEEP (*crtbegin.o(.ctors))
    /* We don't want to include the .ctor section from
       from the crtend.o file until after the sorted ctors.
       The .ctor section from the crtend file contains the
       end of ctors marker and it must be last */
    KEEP (*(EXCLUDE_FILE (*crtend.o) .ctors))
    KEEP (*(SORT(.ctors.*)))
    KEEP (*(.ctors))
  }
  [...]

> The result of the constructor section is the following:
>
>   .ctors         0x0000000090092030        0x4 /tmp/ecos/spartan3adsp_net/install/lib/libtarget.a(compat_posix_pthread.o)
>
> With
> a similar application compiled with powerpc-eabi
>
>   .ctors.07535   0x00150684        0x4 /tmp/ecos/mpc8572ds_net/install/lib/libtarget.a(compat_posix_pthread.o)

I suspect that this is en eCos issue, rather than a linker one.  My 
guess would be that the eCos configuration/build system is deciding that 
the microblaze toolchain does not support constructor/destructor 
priorities, and so it is not bothering to annotate the constructor 
section names with their priority.

Have a look at the eCos configuration logs.  Maybe you can find 
something there.

Cheers
  Nick