arm-elf-gcc _sbrk errors

[mdpai]

Hi,
I tried to compile an empty main function (just to test the toolchain) but i got these errors.

fairuz@ubuntu:~/test$ arm-elf-gcc -mcpu=arm7tdmi-s test.c
/opt/gnuarm/lib/gcc/arm-elf/4.4.1/../../../../arm-elf/lib/libc.a(lib_a-exit.o): In function `exit':
/home/fairuz/build-newlib/arm-elf/newlib/libc/stdlib/../../../../../newlib-1.17.0/newlib/libc/stdlib/exit.c:65: undefined reference to `_exit'
/opt/gnuarm/lib/gcc/arm-elf/4.4.1/../../../../arm-elf/lib/libc.a(lib_a-sbrkr.o): In function `_sbrk_r':
/home/fairuz/build-newlib/arm-elf/newlib/libc/reent/../../../../../newlib-1.17.0/newlib/libc/reent/sbrkr.c:60: undefined reference to `_sbrk'
collect2: ld returned 1 exit status

This is my main

void main (void){}

I compile my own toolchain using gcc 4.4.1, binutils 2.19.1, newlib 1.17, GDB 6.8, insight 6.8-1

I've read somewhere that this kind of error is caused by newlib syscall and they suggest to add --disable-newlib-supplied-syscalls option when compiling newlib. I've did this but I still got the same errors.

Anyone have some ideas on this matter?

Thanks for your time,

Kind regards,
Fairuz

 

[srizbf]

it seems that you have not linked the required library.

srizbf
6thjuly2010

 

[amraldo]

Why do not you test it with some code in the main?
--
Amr

 

[mdpai]

I've test it with a sample ARM code that I downloaded and the same error come out.

 

[amraldo]

Is this a bare metal toolchain?
--
Amr

 

[mdpai]

I think it is.. I build it with the guide from gnuarm

 

[amraldo]

If it is, this means it has no os to run on.
Then how do u expect that you will run ur application unless u add some boot code to it or link some runtime initialization?
--
Amr

 

[mdpai]

Thanks for the quick reply.

Sorry I'm new to the cross compiling with ARM. I've downloaded a sample ARM project, and I see they have a *.ld and a *.S. Are these you mean by boot code and linker code? Is it compulsory to have these files. Or did some IDE like CodeBlock (that I configured to run with GNUARM) can generate it from their library?

Thanks,

Kind regards,
Fairuz

 

[amraldo]

*.ld is a linker script while .s is just an assembly file.
Boot codes may be with the IDE or you write them yourself.
It depends on your case my lady.
--
Amr

 

[mdpai]

I will try to find an example project that have all necessary files and compile it to find out what will happen.

Thanks

 

[amraldo]

You have to look for an example that came with your board. For sure they have a working example.
--
Amr

 

[mdpai]

One small question, if I want to compile for an ARM simulator such as Synopsys Innovator or Skyeye, is it different? Since there are no target boards.

 

[amraldo]

No, they should be same.
--
Amr