Re: [avr-gcc-list] how do I pass --defsym to avr-ld?

[Dave N6NZ]

Hi Knut,

Thanks for the reply.  I did try to invoke the linker directly, without 
much luck.

In any case, after a lunch break I concluded that there was a cleaner 
and simpler way to accomplish what I wanted anyway, so I abandoned 
debugging this issue to pursue the alternate implementation, which I 
eventually got working quite nicely. The new scheme is much cleaner and 
doesn't require as much command line trickery.

Hopefully I'll have the whole thing written up soon.

Still, I'm not sure what I was doing wrong with DEFINED(), but I've 
concluded there is something I don't understand about how the linker 
recognizes symbols.

-dave


Schwichtenberg, Knut wrote:
> Dave,
>
> you are using the avr-gcc to pass the parameter to the linker. Did you
> try to use the linker directly with 
>
> avr-ld --script=avr5.x --defsym=__libdatareserve=0x4 -o user user.o
> bootlibentries.o
>
> I'm not sure if the command line is okay :-(.
>
> Knut
> > -----Original Message-----
> > From: 
> > address@hidden
> > g 
> > [mailto:address@hidden
> ongnu.org] On Behalf Of Dave N6NZ
> > Sent: Tuesday, September 30, 2008 10:15 PM
> > To: address@hidden
> > Cc: AVR-GCC
> > Subject: Re: [avr-gcc-list] how do I pass --defsym to avr-ld?
> >
> > Now I'm even more confused.
> >
> > I pass the symbol __libdatareserve in through a .o file.
> > and it shows up in avr-nm output for both the .o and the resulting 
> > output file.  But it still seems to be ignored by the 
> > DEFINED() function.
> >
> > avr-nm shows the symbol -- why doesn't DEFINED() see it????
> >
> > badly need a clue here...
> >
> > -dave
> >
> > Dave N6NZ wrote:
> > > After making many threats, I'm finally attacking the 
> > problem of doing 
> > > separately compiled libraries in a robust fashion.  (I can't bring 
> > > myself to call them dll's since being flashed they are hardly very 
> > > dynamic :)
> > >
> > > I have patched the avr5.x ld script as follows, which is a 
> > total of 3 
> > > additional lines, all upward compatible:
> > >
> > > diff -u /usr/local/atmel/avr/lib/ldscripts/avr5.x avr5.x
> > > --- /usr/local/atmel/avr/lib/ldscripts/avr5.x   2007-07-27 
> > > 23:12:51.000000000 -0700
> > > +++ avr5.x      2008-09-30 11:53:10.000000000 -0700
> > > @@ -71,6 +71,7 @@
> > >    {
> > >      *(.vectors)
> > >      KEEP(*(.vectors))
> > > +    *(.entryjumps)
> > >      /* For data that needs to reside in the lower 64k of 
> > progmem.  */
> > >      *(.progmem.gcc*)
> > >      *(.progmem*)
> > > @@ -145,6 +146,7 @@
> > >    }  > text
> > >    .data          : AT (ADDR (.text) + SIZEOF (.text))
> > >    {
> > > +     . += DEFINED (__libdatareserve) ? __libdatareserve : 0 ;
> > >       PROVIDE (__data_start = .) ;
> > >      *(.data)
> > >      *(.data*)
> > > @@ -176,6 +178,7 @@
> > >    }  > data
> > >    .eeprom  :
> > >    {
> > > +    . += DEFINED(__libeepromreserve) ? __libeepromreserve : 0 ;
> > >      *(.eeprom*)
> > >       __eeprom_end = . ;
> > >    }  > eeprom
> > >
> > > My current problem revolves around the DEFINED() operator 
> > in avr-ld.  It 
> > > does not seem to recognize my definitions, invoked as follows:
> > >
> > > avr-gcc -Wl,--script=avr5.x,--defsym=__libdatareserve=0x4 -o user \
> > > user.o bootlibentries.o
> > >
> > > No matter what I do, it appears as if the DEFINED() is 
> > being ignored. 
> > > Perhaps I misunderstand how DEFINED() is supposed to work, 
> > or perhaps I 
> > > misunderstand --defsym.
> > >
> > > If I could solve this, then I believe I have the 
> > gold-plated solution 
> > > for calling separately flashed libraries (ie: reusing bootloader 
> > > functions.)  I'll write that up fully after resolving this 
> > annoyance.
> > > -dave
> > >
> > >
> > >
> > > _______________________________________________
> > > AVR-GCC-list mailing list
> > > address@hidden
> > > http://lists.nongnu.org/mailman/listinfo/avr-gcc-list
> >
> >
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