[yocto] are separate -sdk image targets necessary Was: Build external module against Yocto kernel

[Zhang, Jessica]

Hi Trevor,

-c populate_sdk will generate a SDK that matches the target image, while an -sdk image allows people to use it to boot up device and do development work on target as you can see in the requirements of bug 1614. The other usage of an -sdk image is to extract its rootfs and use it as your cross development sysroot, if you want to use your toolchain against different sysroot(s).

Thanks,
Jessica

-----Original Message-----
From: Trevor Woerner [mailto:twoerner at gmail.com]
Sent: Wednesday, January 23, 2013 8:51 AM
To: Zhang, Jessica
Cc: yocto at yoctoproject.org
Subject: are separate -sdk image targets necessary Was: [yocto] Build external module against Yocto kernel

On Tue, Jan 15, 2013 at 2:16 PM, Zhang, Jessica <jessica.zhang at intel.com> wrote:
> According to bug 1614, the kernel dev packages should be included in
> sdk images. Please generate your toolchain using "bitbake
> core-image-sato-sdk -c populate_sdk" which will make the toolchain
> target sysroot matching your image's sysroot (this is a new feature of
> 1.3) as long as your image is a sdk image.

I am a bit confused by the above email. To me it appears as if Jessica is saying: "add '-c populate_sdk' to the build of an -sdk image".

But if we look at this email from Mark Hatle:
http://www.mail-archive.com/yocto@yoctoproject.org/msg10636.html

I get the impression that Mark is saying: "now that '-c populate_sdk'
is available, there no longer is any need for separate -sdk images".

Am I confusing two different things with each other?