[yocto] cannot compile kernel module - headers missing

[Jens Rapp]

hi,

i have a simple hello world kernel module and i cannot compile it. linux 
headers are missing
i tried to set -I $(OECORE_TARGET_SYSROOT)usr/src/kernel/include/
but there seems to be much more missing..

is there any way to do this easier?

here's what i have:

module.c
-------------
#include <linux/module.h>
#include <linux/spi.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>

#include <linux/kernel.h>

/**
  * initialisiert das Kernel - Modul
  */
int init_module(void) {
     printk(KERN_DEBUG "Hallo Kernel!\n");
     return 0;
}

void cleanup_module (void) {
     printk (KERN_DEBUG "Ciao!\n");
}


and my Makefile
----------------------
# file      Makefile
# copyright Copyright (c) 2012 Toradex AG
#           [Software License Agreement]
# author    $Author$
# version   $Rev$
# date      $Date$
# brief     a simple makefile to (cross) compile.
#           uses the openembedded provided sysroot and toolchain
# target    linux on Colibri T20 / Colibri T30
# caveats   -

##############################################################################
# Setup your project settings
##############################################################################

# Set the input source files, the binary name and used libraries to link
SRCS = module.c
PROG := module
LIBS =
CONF_LIBS =
C_FLAGS = -D__KERNEL__ -D__SMP__ -DMODULE -DMODVERSIONS
# Set flags to the compiler and linker
CFLAGS += -O2 -g -Wall `$(PKG-CONFIG) --cflags $(CONF_LIBS)` 
$(ARCH_CFLAGS) $(C_FLAGS)
LDFLAGS += `$(PKG-CONFIG) --libs $(CONF_LIBS)`

##############################################################################
# Setup your build environment
##############################################################################

# Set the path to the oe built sysroot and
# Set the prefix for the cross compiler
OECORE_NATIVE_SYSROOT ?= 
$(HOME)/oe-core/build/out-eglibc/sysroots/x86_64-linux/
OECORE_TARGET_SYSROOT ?= 
$(HOME)/oe-core/build/out-eglibc/sysroots/apalis-imx6/
CROSS_COMPILE ?= 
$(OECORE_NATIVE_SYSROOT)usr/bin/armv7at2hf-vfp-neon-angstrom-linux-gnueabi/arm-angstrom-linux-gnueabi-

##############################################################################
# The rest of the Makefile usually needs no change
##############################################################################

# Set differencies between native and cross compilation
ifneq ($(strip $(CROSS_COMPILE)),)
   LDFLAGS += -L$(OECORE_TARGET_SYSROOT)usr/lib 
-Wl,-rpath-link,$(OECORE_TARGET_SYSROOT)usr/lib 
-L$(OECORE_TARGET_SYSROOT)lib -Wl,-rpath-link,$(OECORE_TARGET_SYSROOT)lib
   ARCH_CFLAGS = -march=armv7-a -fno-tree-vectorize -mthumb-interwork 
-mfloat-abi=hard -mtune=cortex-a9
   BIN_POSTFIX =
   PKG-CONFIG = export PKG_CONFIG_SYSROOT_DIR=$(OECORE_TARGET_SYSROOT); \
                export 
PKG_CONFIG_PATH=$(OECORE_TARGET_SYSROOT)/usr/lib/pkgconfig/; \
                $(OECORE_NATIVE_SYSROOT)usr/bin/pkg-config
else
# Native compile
   PKG-CONFIG = pkg-config
   ARCH_CFLAGS =
# Append .x86 to the object files and binaries, so that native and cross 
builds can live side by side
   BIN_POSTFIX = .x86
endif

# Toolchain binaries
CC = $(CROSS_COMPILE)gcc
LD = $(CROSS_COMPILE)gcc
STRIP = $(CROSS_COMPILE)strip
RM = rm -f

# Sets the output filename and object files
PROG := $(PROG)$(BIN_POSTFIX)
OBJS = $(SRCS:.c=$(BIN_POSTFIX).o)
DEPS = $(OBJS:.o=.o.d)

# pull in dependency info for *existing* .o files
-include $(DEPS)

all: $(PROG)

$(PROG): $(OBJS) Makefile
     $(CC) $(CFLAGS) -o $@ $(OBJS) $(LIBS) $(LDFLAGS)
     #$(STRIP) $@

%$(BIN_POSTFIX).o: %.c
     $(CC) -c $(CFLAGS) -o $@ $<
     $(CC) -MM $(CFLAGS) $< > $@.d

clean:
     $(RM) $(OBJS) $(PROG) $(DEPS)

.PHONY: all clean