I am learning how to write linux device driver and wrote a simple usb driver for my Microchip PIC 32 usb starter board.

In the "probe" and "disconnect" function of my kernel module code, several usb functions (interface_to_usbdev, usb_get_intfdata, usb_get_dev, usb_set_intfdata, usb_put_dev) are used.

Compiling succeeded (there are some warnings though). However, when I tried to load the module with "insmod mydriver.o", I got the following error messages:

mydriver.o: unresolved symbol interface_to_usbdev
mydriver.o: unresolved symbol usb_get_intfdata
mydriver.o: unresolved symbol usb_get_dev
mydriver.o: unresolved symbol usb_set_intfdata
mydriver.o: unresolved symbol usb_put_dev

I googled for a while without any luck. Somebody said kernel source should be installed. But I already had kernel-source-2.4.20-8.i386.rpm installed. I am using redhat9 with kernel 2.4.20-8.

I also checked the loaded modules and made sure that usbcore module has been loaded.

Below is my Makefile:

------------------------------------------------------
TARGET := mydriver
WARN := -W -Wall -Wstrict-prototypes -Wmissing-prototypes
INCLUDE := -isystem /lib/modules/`uname -r`/build/include
CFLAGS := -O2 -DMODULE -D__KERNEL__ ${WARN} ${INCLUDE}
CC := gcc

${TARGET}.o: ${TARGET}.c

.PHONY: clean

clean:
rm -rf ${TARGET}.o
----------------------------------------------------------


Anybody has an idea of how to solve this problem? Thanks in advance.

A lot of the advice you will see/read will presume kernel-2.6x - you are aware of that?

These errors show because these names come up as possibly needed (e.g. a library) and your box hasn't a clue where you stuffed it.

Try compiling a static (=self contained) version.

I am new to linux programming. Could you please show me how to compile a static version?

The standard setup for linux programming is:
gcc - compiler
kernel headers - include functions
glibc - = all the main pc basic stuff (cfopy, write, print, etc) &
ld - the linker. also utilities to see what libs are missing. Try ldd </path/to/your_program>

That lot form your toolchain, upon which the integrity of your program depends. Now add
Makefiles - in every directory
./configure script - to check for all needed parts and twead the Makefiles

There's a HOWTO on tldp.org for programming in linux. Grab that.