ARM bug in newlib?

[Jeff Johnston]

Joe Pencak wrote:

>I have built newlib-1.12.0 to work with a GCC ARM cross compiler. Newlib
>was configured as follows on a Pentium II running
>Windows:
>
>  
>
>>../newlib-1.12.0/configure \
>>  --enable-languages=c \
>>  --target=arm-elf \
>>  --program-prefix=arm- \
>>  --prefix=/usr/local/arm
>>    
>>
>
>When I use function atoi() in my code, I get the following linker
>errors:
>
>  
>
>>\usr\local\arm\arm-elf\lib/libc.a(strtol.o)(.text+0x90): In function
>>    
>>
>`_strtol_r'
>  
>
>>:
>>../../../../../newlib-1.12.0/newlib/libc/stdlib/strtol.c:186: undefined
>>    
>>
>referenc
>  
>
>>e to `__umodsi3'
>>\usr\local\arm\arm-elf\lib/libc.a(strtol.o)(.text+0xa0):../../../../../newlib-1.
>>    
>>
>
>  
>
>>12.0/newlib/libc/stdlib/strtol.c:187: undefined reference to
>>    
>>
>`__udivsi3'
>
>The code was linked as follows:
>
>  
>
>>arm-ld -d -b elf32-littlearm -e __start -EL -static -nostdlib
>>    
>>
>-nostartfiles -L\u
>  
>
>>sr\local\arm\arm-elf\lib  -T linker-arm-gcc.lcf  _vectors.o
>>    
>>
>_startup.o  exceptions
>  
>
>>.o  main.o -lc -lm -Map a.map -o a.elf
>>    
>>
>
>References to __umodsi3 and __udivsi3 appear in divsi3.c in
>machine/h8500 and machine/w65, but not in machine/arm.
>Apparently, when newlib is built for ARM, there is no divsi3.c with the
>necessary references. A bug?
>I've built newlib like this for the PowerPC and had no such problem.
>  
>
Joe,

  The function __udivsi3 and __umodsi3 are in libgcc, not newlib.  
Standard operations like
multiply, divide, mod, etc.. can require the compiler to issue function 
calls which are resolved in
libgcc.  In your case, it is a divide and a mod operation.  On platforms 
where there
are insns to support such operations, the compiler simply generates the 
appropriate code.  Thus, you
may see differences from platform to platform.

  Try adding -lgcc to your link and remember to add a -L reference to 
the proper location of the
libgcc for your compiler options (libgcc gets multilib'ed like newlib does).

-- Jeff J.