[oe] Adding sumtool to a JFFS2 build to speed up first boot

[Andrea Adami]

On Sat, Oct 29, 2011 at 7:14 PM, Tom Rini <tom.rini at gmail.com> wrote:

> On Sat, Oct 29, 2011 at 9:27 AM, Ulf Samuelsson
> <ulf_samuelsson at telia.com> wrote:
> > Trying to solve another problem I came up with
> > changing IMAGE_CMD_jffs2 defined in conf/bitbake.conf
> > by redefining it in conf/local.conf.
> >
> > During that process I noticed the "sumtool" utility
> > which works on the jffs2 image, doing some
> > bookkeeping which then does not have to be
> > done on the target.
> >
> > I unserstand, this can speed up loading significantly.
> > Any reason not using this in OE?
>
> Last time I looked at this, the reason was that you had to re-jigger
> the IMAGE_CMD a bit and you also have to take care as not all of the
> options are the same between mkfs.jffs2 and sumtool.  At least the
> first part might be easier with oe-core and the reworked image class.
> The latter part is just annoying.
>
> --
> Tom
>
> FWIW we are defining our jffs2-summary in
http://cgit.openembedded.org/meta-handheld/tree/conf/machine/include/zaurus.inc

This works beautifully in oe-dev but not using oe-core for it sets
IMAGE_CMD_jffs2 = and this can  not be overriden
We would just need a weak assignment in image_types.bbclass or maybe a new
image type like IMAGE_CMD_jffs2-summary and related commands.

Regards

Andrea