Question: How do I include the linux kernel headers as part of the SDK package in Yocto?

I'm using Yocto 1.8 (fido) in an embedded project and want to do out-of-tree kernel module development. Currently, I can build my kernel modules (apart from bitbake) by pointing my `$KERNEL_PATH` to the `poky/build/tmp/work-shared/<machine>/kernel-source/` directory when I run make. I don't want to do this in the long term, however, since others need to easily build the modules without installing and building a full image from bitbake. 

I can generate an SDK using `bitbake myimage -c populate_sdk`. However, this doesn't include the kernel headers (all I ever see is `sysroots/<mach>/usr/include/linux`). How do I cause the kernel headers to be included in the SDK package? Also, I don't want the kernel headers to show up as part of my target image.

**[Edit]**
My image recipe is as follows:

```
EXTRA_IMAGE_FEATURES_append = " eclipse-debug debug-tweaks"
TOOLCHAIN_HOST_TASK_append = " nativesdk-cmake"
IMAGE_INSTALL = "packagegroup-core-boot  ${CORE_IMAGE_EXTRA_INSTALL} util-linux kernel-modules netbase busybox base-passwd base-files sysvinit initscripts bash gdbserver strace sysfsutils dtc gawk ethtool grep sed wget  iptables oprofile net-tools dropbear rsync stress-ng rt-tests i2c-tools"
inherit core-image

```

The kernel I'm using is [linux-altera-ltsi-rt](https://github.com/kraj/meta-altera/blob/master/recipes-kernel/linux/linux-altera-ltsi-rt_3.10.bb) in the meta-altera layer.

Answer: 
[anders](https://stackoverflow.com/users/4093778/anders) [answer](https://stackoverflow.com/a/31261404/14675992) is very good, but in recent versions of yocto the way to add kernel-devsrc seems to be

`IMAGE_INSTALL += "kernel-devsrc"`

which I found here: <https://www.mail-archive.com/yocto@yoctoproject.org/msg36448.html>
With Yocto Zeus (3.0.x) add this to your image recipe:

```
    TOOLCHAIN_TARGET_TASK += "kernel-devsrc"

```

EDIT: Same for Gatesgarth (3.2.x) but the `make scripts` command has a new host dependency to `libyaml-dev`