How to compile driver in Nios2uclinux

It's also possible to compile your driver as a kernel module outside of the source tree. Take a look at:

lwn: driver porting (http://lwn.net/articles/21823/)

The only thing that you would have to do differently to get it working is to specify an output directory on the make commandline from within the example makefile.

...
KDIR = $(KERNEL_PlUGIN)/linux-2.6.x
BUILDDIR = $(ECLIPSE_WORKSPACE)/kernel_project/build
...
$(MAKE) -C $(KDIR) O=$(BUILDDIR) SUBDIR=$(PWD) modules
...

After compiling the module, you can upload it to your filesystem or copy it into a filesystem project and re-upload the filesystem project.