Re: My problem with the LD linker

[Marian Kechlibar <marian dot kechlibar at circletech dot net>]

Hi Nick,

thank you for your suggestions.

ARMLINK 2.2 will not work with objects compiled by GCC 4.6.3, complains
about invalid object file.

I was nevertheless lucky anyway, though it is embarrasing to admit. My
LD of 2.27 version works! The trouble was that when I substituted LD
2.21 for the newer 2.27, I did not notice that another copy of the
older, faulty 2.21 lingered somewhere on the disk, and unfortunately on
the system path.

As soon as I discovered it and got rid of it, things got better. I can
link my EXE now. It is only about 9 MB big, not a big deal.

Thank you for your help.

Marian

Dne 22.2.2017 v 13:07 Nick Clifton napsal(a):
> Hi Marian,
> 
>> I can compile and link them either using:
>>
>> * ARMCC/ARMLINK 2.2
>> or
>> * GCC(E) 4.6.3 and Binutils 2.21 or 2.27.
> 
>> The second option (GCC/Binutils) works for the first four projects, but
>> the link phase (using ld) fails for the fifth project, saying:
>>
>> ========================================================================
>> arm-none-symbianelf-ld:
>> \S60\devices\S60_3rd_FP2_SDK_v1.1\epoc32\release\ARMV5\urel\EEXE.LIB(uc_exe_.o)(.text+0x2):
>> unresolvable R_ARM_THM_CALL relocation against symbol
>> `_ZN4User9InvariantEv@@euser{000a0000}[100039e5].dll'
> 
> 
>> I have a suspicion that the problem is in *size* of the resulting
>> binary. The "Expert" project is rather big, several times bigger
>> than the "Cleaner" project. But I do not understand ELF well enough
>> to remedy the problem.
> 
>> Is it possible that some section of the resulting ELF file overflows?
> 
> Yes.  It may well be that the executable is so big that the distance from where
> the Invariant function is being called and where it is being defined will not
> fit into the Thumb function call instruction.
> 
> Several ideas come to mind:
> 
>   * Compile for ARM rather than THUMB - the ARM supports a larger address space.
> 
>   * Compile with GCC but link with ARMLINK.  (You did say that using ARMCC/ARMLINK works).
> 
>   * Compile with -ffunction-sections and -fdata-sections enabled and then link with -gc-sections enabled.
>     This might help to reduce the code size by eliminating unused code/data.
> 
>   * Change the order of the object files on the linker command line so that uc_exe.o
>     object is located closer to the system library that defines it.
> 
>   * Compile with -mlong-calls enabled so that function calls to far away destinations should work.
> 
> Cheers
>   Nick
> 
>