用于OpenWrt的Eclipse GCC C交叉编译不起作用

Question

I am a beginner in both linux and openwrt. Sorry if this is a stupid question.

I am following this tutorial : https://downloads.openwrt.org/docs/eclipse.pdf

• Chip : MT7620
• Toolchain Prefix : mipsel-openwrt-linux-
• Toolchain Path : /ligo/openwrt/staging_dir/toolchain-mipsel_24kec+dsp_gcc-5.3.0_musl-1.1.14

Code:

#include <stdio.h>
void main()
{
    printf("Hello World");
}

Error:

**** Build of configuration Debug for project hello ****
make all 
Building target: hello
Invoking: Cross GCC Linker
mipsel-openwrt-linux-gcc -L/ligo/openwrt/staging_dir/toolchain-mipsel_24kec+dsp_gcc-5.3.0_musl-1.1.14/lib -o"hello"  ./main.o   
mipsel-openwrt-linux-gcc: warning: environment variable 'STAGING_DIR' not defined
mipsel-openwrt-linux-gcc: warning: environment variable 'STAGING_DIR' not defined
/ligo/openwrt/staging_dir/toolchain-mipsel_24kec+dsp_gcc-5.3.0_musl-1.1.14/lib/gcc/mipsel-openwrt-linux-musl/5.3.0/../../../../mipsel-openwrt-linux-musl/lib/crt1.o: In function `_start_c':
/ligo/openwrt/build_dir/toolchain-mipsel_24kec+dsp_gcc-5.3.0_musl-1.1.14/musl-1.1.14/crt/crt1.c:17: undefined reference to `main'
/ligo/openwrt/build_dir/toolchain-mipsel_24kec+dsp_gcc-5.3.0_musl-1.1.14/musl-1.1.14/crt/crt1.c:17: undefined reference to `main'
collect2: error: ld returned 1 exit status
make: *** [hello] Error 1

Answer 1

add the following 2 lines at the end of bashrc

• export PATH=$PATH:~/openwrt/staging_dir/toolchain-mipsel_24kec+dsp_gcc-4.8-linaro_uClibc-0.9.33.2/bin export STAGING_DIR=~/openwrt/staging_dir

• source ~/.bashrc

To open/create the bashrc you can execute

• sudo gedit ~/.bashrc

Answer 2

Well I feel stupid when I have to figure this problem which happens too often.

I get the above error when I forget to save the file that contains main() it gives this error since the file is empty until you save it.

These instructions tell how to automatically save all the modified files when you kick off a build Save before build Keep this set and you won't see this again.

If you don't have the path to the toolchain set in eclipse, it never even finds a compiler, assembler or linker so it can not produce the error given. The warnings about STAGING_DIR are harmless in this case.