linuxkernelyoctotoolchainintel-galileo

Intel Galileo adding kernel header files to the cross compile toolchain

im on BSP v1.1 yocto is 1.6

I'm trying to set up the cross compile toolchain to compile character driver code but the output i get is

[mark@localhost ~]$ ${CC} first.c -o first

first.c:1:24: fatal error: linux/init.h: No such file or directory

.#include ^ compilation terminated.

I think the issue is that the header is not in the toolchain /opt/iot-devkit/1.6.1/sysroots/i586-poky-linux/usr/include/linux/~ there is no at this location

I think something has to be added as IMAGE_INSTALL or IMAGE_FEATURE but i dont know what

am I on the right track ? does anyone know what i have to add ? or am i completely off tracks altogether?

Solution

  • Well, first and foremost, you can never build a kernel module by just running ${CC} on it. You should always use a Makefile, which redirects most of its work to the kernel source Makefil.

    Create a Makefile for you module, consisting of something similar to:

    obj-m += hello-1.o

all:
    make -C  $(KERNEL_SRC M=$(PWD) modules

clean:
    make -C  $(KERNEL_SRC) M=$(PWD) clean

    Example taken from The Linux Kernel Module Programming Guide (Note that the actual commands needs to have a tab character for indentation).

    Then you'll have to define KERNEL_SRC to be /opt/iot-devkit/1.6.1/sysroots/i586-poky-linux/usr/src/kernel/, either in the Makefile, or from your make call. (Using a variable like KERNEL_SRC will ensure that your module recipe automatically picks the right location when building using bitbake).

    To manually build your kernel module:

    1. Source the environment-* file for your SDK.
    2. Go to you modules directory.
    3. KERNEL_SRC=/opt/iot-devkit/1.6.1/sysroots/i586-poky-linux/usr/src/kernel LDFLAGS="" make However, this will fail, as fixdep can't be found. We'll fix this manually.
    4. cd /opt/iot-devkit/1.6.1/sysroots/i586-poky-linux/usr/src/kernel
    5. make silentoldconfig scripts
    6. Go back to your modules directory.
    7. KERNEL_SRC=/opt/iot-devkit/1.6.1/sysroots/i586-poky-linux/usr/src/kernel LDFLAGS="" make

    This should now produce hello.ko which you should be able to insmod on the Galileo board.