Kernel module makefile output name

Question

I am trying to compile my kernel module. The .c file name is file1.c, but I need the .ko file name to be mod1.ko.

How can I do that?

My current makefile:

obj-m := mod1.o
KDIR :=/lib/modules/$(shell uname -r)/build
PDW := $(shell pwd)

all:
    $(MAKE) -C $(KDIR) M=$(PDW) modules

clean:
    $(MAKE) -C $(KDIR) M=$(PDW) clean

Answer 1

You should change your first line to something like this:

obj-m += module_name.o
module_name-y := file1.o

Where module_name is the module file name (in this example the output will be module_name.ko) and it will be build from file1.c. You can add more than one source file to the 2nd line, so it could be:

module_name-y := file1.o file2.o file3.o

In this case module_name.ko will be build from file1.c, file2.c and file3.c.

You should read this document if you want to fully understand Linux kernel makefiles. Your problem is described somewhere around line 190.

Answer 2

The solution looks like this:

obj-m += mod1.o
mod1-objs := file1.o

KBUILD_CPPFLAGS += -I$(PWD)/

all:
    make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

clean:
    make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean