Linux device driver module compilation using gcc - linux

Question

I have a basic linux device driver module :
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
static int __init hello_init(void)
{
printk(KERN_ALERT "Hello, world \n");
return 0;
}
static void __exit hello_exit(void)
{
printk(KERN_ALERT "Goodbye, world \n");
}
module_init(hello_init);
module_exit(hello_exit);
I am able to compile this module in traditional way which is by using a simple Makefile which uses obj-m , but I want to compile this using command line gcc. This is because I can use gcc -save-temps flag to see the intermediate generated files(this can be particularly helpful to understand as Linux kernel uses lot of preprocessor stuff).
So is there a way to compile using command line gcc ??
EDIT Attaching the Makefile I have used
ifeq ($(KERNELRELEASE),)
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)
EXTRA_CFLAGS+= -save-temps
modules:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
modules_install:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install
clean:
rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions
.PHONY: modules modules_install clean
else
obj-m := hello.o
endif

Answer 1

Could you try to add "EXTRA_CFLAGS" in your module's Makefile?
such as EXTRA_CFLAGS += -save-temps
Hope it help you!

Answer 2

I don't know how to to that directly in Makefile, but you can generate your .i file by file. From the root directory of the Linux kernel source:
make drivers/media/pci/sta2x11/sta2x11_vip.i
This will generate the .i file. To generate your module source file (which is outside the kernel tree) just use the absolute path to it:
make /path/to/hello.i
It should work