Re: [PATCH] kernel.bbclass: add lzop dependency

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Wed, 2016-08-10 at 09:07 -0700, Khem Raj wrote:
> On Aug 10, 2016 1:59 AM, "Richard Purdie" <
> richard.purdie@linuxfoundation.org> wrote:
> >
> > On Tue, 2016-08-09 at 12:27 -0700, Khem Raj wrote:
> > > > On Aug 9, 2016, at 5:08 AM, Mike Looijmans <
> mike.looijmans@topic.nl
> > > > > wrote:
> > > >
> > > > I've been adding "lzop-native" to a lot of kernel recipes
> because
> > > > you also need it when generating an LZO compressed kernel (I
> like
> > > > my boot time to be under 1 second).
> > > >
> > > > It's a small dependency which is hard to automatically figure
> out,
> > > > since there are a number of ways to trigger it (we just found
> two).
> > > > I would welcome this patch very much, and I don't think many
> will
> > > > suffer…
> > >
> > > From linux.inc days there is a python snippet which can do this
> > > conditionally e.g. see
> > >
> > > 
> https://github.com/kraj/meta-raspberrypi/blob/master/recipes-kernel/l
> > > inux/linux-rpi.inc#L121
> >
> > Which is fine if you have a prebuild defconfig file however in many
> > cases we don't have that :(
> >
> Thats right perhaps dependency could be conputed after configure task
> and added to say compile task

Bitbake computes the dependency trees in advance, not on the fly so its
sadly not possible to change the dependency graph during a running
build. I'm sure you could design such a system but its not what we have
today, nor does it likely warrant the extra complexity it could
involve.

Cheers,

Richard