I have a "Linksys WRT1200AC" router running "OpenWrt Chaos Calmer 15.05.1" (mvebu Architecture) with "gcc_4.8.3-1_mvebu.ipk" and all other required packages installed.
I've tried to compile a C source file (something easy, similar to "hello world") with the command:
#gcc mysource.c -o myprogram
#chmod +x myprogram
#./myprogram
myprogram: line 1: syntax error: unexpected word (expecting ")")
The compiler gives me no errors or warnings, but the program can't be started. It's like installing a .ipk package from a different arch to the router. So I think that gcc is compiling my source for a different CPU/Arch. The router cpu is: "Marvell Armada 38X dual-core @ 1.33 GHz (88F6820-A0 C133)"
# uname -a
Linux OW 3.18.23 #1 SMP Sun Jan 31 12:53:24 CET 2016 armv7l GNU/Linux
# grep 'model name' /proc/cpuinfo
model name : ARMv7 Processor rev 1 (v7l)
model name : ARMv7 Processor rev 1 (v7l)
What is the correct command line to compile my sources inside openwrt with the right CPU/Arch option? I've tried with different "-march/-mcpu" but no success.
This is with verbose on:
# gcc -v mysource.c -o myprogram
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/arm-openwrt-linux-uclibcgnueabi/4.8.3/lto-wrapper
Target: arm-openwrt-linux-uclibcgnueabi
Configured with: /home/buildbot/slave-local/mvebu_generic/build/build_dir/target-arm_cortex-a9+vfpv3_uClibc-0.9.33.2_eabi/gcc-4.8.3/configure --target=arm-openwrt-linux --host=arm-openwrt-linux --build=x86_64-linux-gnu --program-prefix= --program-suffix= --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --libexecdir=/usr/lib --sysconfdir=/etc --datadir=/usr/share --localstatedir=/var --mandir=/usr/man --infodir=/usr/info --disable-nls --build=x86_64-linux-gnu --host=arm-openwrt-linux-uclibcgnueabi --target=arm-openwrt-linux-uclibcgnueabi --enable-languages=c,c++ --with-bugurl=https://dev.openwrt.org/ --with-pkgversion='OpenWrt GCC 4.8.3' --enable-shared --disable-__cxa_atexit --enable-target-optspace --with-gnu-ld --disable-nls --disable-libmudflap --disable-multilib --disable-libgomp --disable-libquadmath --disable-libssp --disable-decimal-float --disable-libstdcxx-pch --with-host-libstdcxx=-lstdc++ --prefix=/usr --libexecdir=/usr/lib --with-float=soft
Thread model: posix
gcc version 4.8.3 (OpenWrt GCC 4.8.3)
COLLECT_GCC_OPTIONS='-v' '-o' 'myprogram' '-mfloat-abi=soft' '-mtls-dialect=gnu'
/usr/lib/gcc/arm-openwrt-linux-uclibcgnueabi/4.8.3/cc1 -quiet -v -imultilib . -imultiarch arm-linux-gnueabi mysource.c -quiet -dumpbase myprogram.c -mfloat-abi=soft -mtls-dialect=gnu -auxbase mysource -version -o /tmp/ccojawQz.s
GNU C (OpenWrt GCC 4.8.3) version 4.8.3 (arm-openwrt-linux-uclibcgnueabi)
compiled by GNU C version 4.8.3, GMP version 4.3.2, MPFR version 2.4.2, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
ignoring nonexistent directory "/usr/local/include/arm-linux-gnueabi"
ignoring nonexistent directory "/usr/local/include"
ignoring nonexistent directory "/usr/lib/gcc/arm-openwrt-linux-uclibcgnueabi/4.8.3/../../../../arm-openwrt-linux-uclibcgnueabi/include"
ignoring nonexistent directory "/usr/include/arm-linux-gnueabi"
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/arm-openwrt-linux-uclibcgnueabi/4.8.3/include
/usr/lib/gcc/arm-openwrt-linux-uclibcgnueabi/4.8.3/include-fixed
/usr/include
End of search list.
GNU C (OpenWrt GCC 4.8.3) version 4.8.3 (arm-openwrt-linux-uclibcgnueabi)
compiled by GNU C version 4.8.3, GMP version 4.3.2, MPFR version 2.4.2, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Well, seems that is working this way ;)
gcc -mabi=aapcs-linux mysource.c -o myprogram