linking custom executable

linking custom executable

[Alexander Gdalevich]

Greetings,

I am running into a strange problem using a pc-cygwin hosted GCC 3.4.0 cross 
compiler for the Hitachi sh4 (sh-elf) target.

I have to build an executable image for an embedded system.  I order to call 
global constructors, the program has to call __do_global_ctors_aux() at some 
point before calling main().  This function (__do_global_ctors_aux) is in 
crtend.o.  Normally, collect2 will generate the code to do all the 
initialization, call global constructors and call main().  However, I cannot 
do this since my program has to do some custom hardware initialization 
before running any user or library code.  Hence, what I am trying to do is 
to call __do_global_ctors_aux() directly from my code after I am done with 
initialization.

I am, however, running into trouble linking the program.

This works:
ld crtbegin.o crtend.o my_program.o -lgcc

This, however, does not work:
ld –oformat=binary crtbegin.o crtend.o my_program.o –lgcc

crtbegin.o(.text+0x54): In function `___do_global_dtors_aux':
: undefined reference to `___deregister_frame_info'
crtbegin.o(.text+0xa8): In function `_frame_dummy':
: undefined reference to `___register_frame_info'
crtbegin.o(.text+0xb8): In function `_frame_dummy':
: undefined reference to `__Jv_RegisterClasses'


Is this a bug???


However, when I call __do_global_ctors_aux() from my program, it does not 
link no matter what.  When I instructed the linker to produce map with –M 
option, and looked at the file generated, I saw that even so .init, .text, 
and other sections from crtbegin.o and crtend.o are being linked in, no 
global symbols such as __do_global_ctors_aux and __do_global_dtors_aux 
appear in the list.


What am I doing wrong?


Thanks for your time.


                                                Alexander Gdalevich


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