Kernel development on Nios Linux 2.6 distribution

Previous answer is not enough to build a module independantly from Kernel. My goal is to have my source files on a separate directory (which is handled by a Software Configuration Manager, here ClearCase) with a Makefile to generate the .o module file.

I try to get back the compilation options from the .xxx.o.cmd file in kernel/build/drivers directory. I can now compile files and generate a module without any warning nor error. But this .o file is not recognized by insmod : it gives the following error message :

No module found in object

insmod: cannot insert "testModule_mod.o": Invalid module format (-1): Exec format error

Here is the Makefile (a little bit ... complicated !). With this Makefile, I tried to re-compile one Kernel driver, and I'm very surprise to find an object with a different size (124kb instead of 126kb) : I surely made a mistake, but I can't see where (no errors, no warning... but a little small difference !).

all: testModule_mod.o
testModule_mod.o: testModule.o
    nios2-elf-ld  -mnios2elf  -r -o testModule_mod.o testModule.o
testModule.o: testModule.c Makefile
    nios2-elf-gcc -nostdinc -Wp,-MD,.testModule.o.d -iwithprefix include -D__KERNEL__ -Iinclude -Iinclude2 -I/cygdrive/c/altera/kits/nios2/bin/eclipse/plugins/com.microtronix.nios2linux.kernel_0.1.5/linux-2.6.x/include -I/cygdrive/c/altera/kits/nios2/bin/eclipse/plugins/com.microtronix.nios2linux.kernel_0.1.5/linux-2.6.x/ -I$(LIBMYKERNEL) -I$(LIBKERNEL) -D__KERNEL__ -I/cygdrive/c/altera/kits/nios2/bin/eclipse/plugins/com.microtronix.nios2linux.kernel_0.1.5/linux-2.6.x/include -Iinclude -I/cygdrive/c/altera/kits/nios2/bin/eclipse/plugins/com.microtronix.nios2linux.kernel_0.1.5/linux-2.6.x/include2 -Iinclude2  -I/cygdrive/c/altera/kits/nios2/bin/eclipse/plugins/com.microtronix.nios2linux.kernel_0.1.5/linux-2.6.x/include -Wall -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -DNO_MM -pipe -D__linux__ -D__ELF__ -DNO_TEXT_SECTIONS -fno-builtin -O2 -g -G 0 -DUTS_SYSNAME=\"uClinux\"  -I/cygdrive/c/altera/kits/nios2/bin/nios2-gnutools/H-i686-pc-cygwin/bin/../lib/gcc-lib/nios2-elf/3.3.3/include -O2 -fomit-frame-pointer  -DKBUILD_BASENAME=testModule  -DMODULE -c -o testModule.o testModule.c