Fun with the dynamic loader.

[Bernd Schmidt]

Rob Landley wrote:
> On Friday 14 November 2008 07:31:02 Bernd Schmidt wrote:
>> Rob Landley wrote:
>>> On Thursday 13 November 2008 21:14:39 Rob Landley wrote:
>>>> Only three architectures actually #define this macro: frv, bfin, and
>>>> avr32.
>>> And while we're at it: frv and bfin define START() to do exactly the same
>>> thing.  Does anybody know why it's doing this and why the calling code
>>> hasn't just got an if() case for whatever it is?
>> Uhhh???  This is from bfin/dl-startup.h:
>>
>> /*
>>  * Transfer control to the user's application, once the dynamic loader
>>  * is done.  We return the address of the function's entry point to
>>  * _dl_boot, see boot1_arch.h.
>>  */
>> #define START() do {                                                    \
>>   struct elf_resolve *exec_mod = _dl_loaded_modules;                    \
>>   dl_main_funcdesc->entry_point = _dl_elf_main;                         \
>>   while (exec_mod->libtype != elf_executable)                           \
>>     exec_mod = exec_mod->next;                                          \
>>   dl_main_funcdesc->got_value = exec_mod->loadaddr.got_value;           \
>>   return;                                                               \
>> } while (0)
> 
> And this is from frv:

> The difference?  Acording to diff, the insertion of a commented out debug 
> line.  Hence frv and bfin defining START() to do exactly the same thing.

Oh, ok.  I understood your comment to mean "exact same thing to what
avr32 has", probably because Haavard made a comment to that effect.

Like all the other target-specific macros, it's abstracting away
target-specific stuff.  In the case of bfin and frv, it's FD-PIC related
setup.  So no, you can't remove it, and you can't merge it in with the
main file if you want FD-PIC to remain reasonably abstracted out.


Bernd
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