CODEWITHSUNDEEP
gcccross-compiling
Peter Teoh
Peter Teoh

Reputation: 6753

CodeSourcery ARM cross-compilation

Compiling a simple test.c:

#include <stdio.h>

void main() {
  printf("Hello World!\n");
  while(1);
}

using CodeSourcery's arm-none-eabi-gcc I got the following errors:

arm-none-eabi-gcc -static test.c -o mytest

/opt/Sourcery_CodeBench_Lite_for_ARM_EABI/bin/../lib/gcc/arm-none-eabi/4.8.1/../../../../arm-none-eabi/bin/ld: warning: cannot find entry symbol _start; defaulting to 00008018
/opt/Sourcery_CodeBench_Lite_for_ARM_EABI/bin/../lib/gcc/arm-none-eabi/4.8.1/../../../../arm-none-eabi/lib/libc.a(lib_a-sbrkr.o): In function `_sbrk_r':
sbrkr.c:(.text+0x18): undefined reference to `_sbrk'
/opt/Sourcery_CodeBench_Lite_for_ARM_EABI/bin/../lib/gcc/arm-none-eabi/4.8.1/../../../../arm-none-eabi/lib/libc.a(lib_a-writer.o): In function `_write_r':
writer.c:(.text+0x20): undefined reference to `_write'
/opt/Sourcery_CodeBench_Lite_for_ARM_EABI/bin/../lib/gcc/arm-none-eabi/4.8.1/../../../../arm-none-eabi/lib/libc.a(lib_a-closer.o): In function `_close_r':
closer.c:(.text+0x18): undefined reference to `_close'
/opt/Sourcery_CodeBench_Lite_for_ARM_EABI/bin/../lib/gcc/arm-none-eabi/4.8.1/../../../../arm-none-eabi/lib/libc.a(lib_a-fstatr.o): In function `_fstat_r':
fstatr.c:(.text+0x1c): undefined reference to `_fstat'
/opt/Sourcery_CodeBench_Lite_for_ARM_EABI/bin/../lib/gcc/arm-none-eabi/4.8.1/../../../../arm-none-eabi/lib/libc.a(lib_a-isattyr.o): In function `_isatty_r':
isattyr.c:(.text+0x18): undefined reference to `_isatty'
/opt/Sourcery_CodeBench_Lite_for_ARM_EABI/bin/../lib/gcc/arm-none-eabi/4.8.1/../../../../arm-none-eabi/lib/libc.a(lib_a-lseekr.o): In function `_lseek_r':
lseekr.c:(.text+0x20): undefined reference to `_lseek'
/opt/Sourcery_CodeBench_Lite_for_ARM_EABI/bin/../lib/gcc/arm-none-eabi/4.8.1/../../../../arm-none-eabi/lib/libc.a(lib_a-readr.o): In function `_read_r':
readr.c:(.text+0x20): undefined reference to `_read'
collect2: error: ld returned 1 exit status

But if i used my Ubuntu (12.04 LTS 32-bit) 's arm gcc:

arm-linux-gnueabi-gcc -static -o mytest test.c 

arm-linux-gnueabi-gcc -v
Using built-in specs.
COLLECT_GCC=arm-linux-gnueabi-gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/arm-linux-gnueabi/4.6/lto-wrapper
Target: arm-linux-gnueabi
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.3-1ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/arm-linux-gnueabi/include/c++/4.6.3 --libdir=/usr/lib --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --enable-multilib --disable-sjlj-exceptions --with-arch=armv7-a --with-float=softfp --with-fpu=vfpv3-d16 --with-mode=thumb --disable-werror --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=arm-linux-gnueabi --program-prefix=arm-linux-gnueabi- --includedir=/usr/arm-linux-gnueabi/include --with-headers=/usr/arm-linux-gnueabi/include --with-libs=/usr/arm-linux-gnueabi/lib
Thread model: posix
gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5)

I have no error generating the output file.

can someone explain?

My best nearest reference (but still I have no success):

Linker error on a C project using eclipse

Upvotes: 1

Views: 1753

Answers (1)

nos
nos

Reputation: 229264

arm-none-eabi-gcc is a compiler for bare metal arm. I.e. for running on an arm processor where you have no operating system, or where you make your own operating system. That compiler contains the newlib C library, which will provide you with most of a standard C library, but you will have to provide the low level implementations (e.g. somewhere for printf() to actually print, memory management, a file system if you need it). In short, you're much on your own having to bootstrap the processor, C runtime and load the produced code (See e.g. this question))

arm-linux-gnueabi-gcc is a compiler for targeting linux running on arm, a toolchain that'll produce executables running on linux, using the familiar glibc C library and header files.

Upvotes: 3

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