[OE-core] Create more than one image with WIC

[Patrick Ohly]

On Tue, 2017-03-14 at 19:11 +0200, Ed Bartosh wrote:
> On Mon, Mar 13, 2017 at 05:16:31PM +0100, Daniel Schultz wrote:
> > Do I have misunderstood the design of wic?
> >
> > I mean MMC and EMMC are very similar, but different in the
> > bootloader and it would be a overhead to create an extra image for
> > all EMMC images.
> 
> You don't need to create more than one rootfs with the same content. You
> can refer to the same rootfs in multiple .wks files, but the recipes
> have to be unique. In your example MMC and EMMC image recipes can create
> directories for boot partition and their .wks files can use those
> directories and common root directory produced by another recipe, e.g.
> by core-image-minimal.

But beware of interaction with rm_work.bbclass when doing that...

> It's not a big deal to run wic sequentially to produce multiple images,
> but it will create more problems than it solves I believe. It will be slower and
> will make a mess in image naming in deploy directory.

I personally would prefer to support generating more than one wic image
per image recipe. The different output files could be distinguished with
an additional suffix (".efi.wic", ".live.wiC", etc.) where the suffix is
either specified by the WKS file or the configuration where the WKS file
is selected - the latter might be a bit more flexible.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.