[yocto] inconsistent pages out there for setting up your yocto dev host

[Paul Eggleton]

On Wednesday 21 November 2012 20:19:05 Robert P. J. Day wrote:
> On Wed, 21 Nov 2012, Paul Eggleton wrote:
> > On Wednesday 21 November 2012 17:23:56 Robert P. J. Day wrote:
> > > as i read it, the sanity.bbclass and ASSUME_PROVIDED will
> > > dictate what needs to be there and what will be used if it's
> > > installed natively, no?  it certainly seems that that wiki page is
> > > insructing the developer to install a lot of software that OE will
> > > handle automatically, no?
> > 
> > Er, no. Well, if by "handle automatically" you mean "error out when
> > they are not present" then that's not very helpful - it's much
> > easier if people just get a list of what they need to install up
> > front.
> 
>   at the risk of asking a dumb question, let me make sure i understand
> the different categories of software.
> 
>   first, there's what is absolutely *required* to be installed on the
> development system already before doing any oe/yocto work.  those
> would the packages/utilities that are listed on the wiki page as "you
> must install this", and that's what's represented in the
> sanity.bbclass.  is that about right?
> 
>   on the other hand, there's what's listed in ASSUME_PROVIDED, which
> represents software that, if it *is* natively installed, will be used;
> otherwise, oe/yocto will download and build it as part of the build
> process.  correct?  or have i misunderstood the distinction here?

I think you may have. All ASSUME_PROVIDED does is tell bitbake that 
dependencies on the things within it should be considered to be satisfied - 
i.e. "assume these things are provided". If you add something to 
ASSUME_PROVIDED that is genuinely needed by the build process and it isn't 
actually provided by the host system, then you will get build failures or at 
the very least undesirable changes in build behaviour.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre