[meta-xilinx] [PATCH] image_types_zynq.bbclass: introduce an SD/eMMC image creation class

[Jean-Francois Dagenais]

> On Mar 14, 2017, at 08:24, Nathan Rossi <nathan at nathanrossi.com> wrote:
> 
> I am not sure if you were aware but there is a tool that is part of OE
> called 'wic' that can be used for creating complete disk images like
> you have done in this bbclass.
> http://www.yoctoproject.org/docs/latest/dev-manual/dev-manual.html#creating-partitioned-images

I was aware of it yeah. Just thought it was cumbersome to have to invoke more
build steps after "bitbake" in order to get my end artifact. We did some
prototyping on an i.mx6 prior to the zynq platform. This class was inspired from
a similar bbclass found in meta-fsl-arm
(https://github.com/Freescale/meta-fsl-arm/blob/master/classes/image_types_fsl.bbclass)

> 
> There is an example which approximately resembles your sdcard layout
> here: http://git.openembedded.org/openembedded-core/tree/scripts/lib/wic/canned-wks/sdimage-bootpart.wks.
> The "bootimg-partition" populates from files defined by the
> "IMAGE_BOOT_FILES" variable. e.g.
> http://git.yoctoproject.org/cgit/cgit.cgi/meta-xilinx/tree/conf/machine/zc702-zynq7.conf#n27

I think it has some value. In all previous projects, bitbake would always build
everything we need to output. We particularly made use of the hddimg FS_TYPE. I
just don't see why an external "wic" had to be invented in the first place...
you can perfectly do everything by extending the existing IMAGE_TYPES framework.

Please educate me if needed!

Enjoy!