I would suggest to use separate build directories but let these builds 
to share downloads and sstate.

Regards,
Chen Qi

On 11/30/2014 12:49 PM, Qiang Yu wrote:
> Hi all,
>
> I'm maintaining a Yocto build system to produce these outputs:
>
> 1. ARM SOC 1
>   1). board 1 image
>   2). board 2 image
>   3). SDK for i686
>   4). SDK for x86_64
> 2. ARM SOC 2
>   1). board 3 image
>   2). board 4 image
>   3). SDK for i686
>   4). SDK for x86_64
>
> Now I don't know the right way to create build directories for these 
> builds. The simplest way
> I think is creating one build directory for each of these builds. But 
> it wast resource for boards
> with the same SOC which can share cross toolchain. And ARM SOC 1 and 
> ARM SOC 2 use
> different conf/bblayers.conf to add different BSP layer, I need to 
> modify it when switch SOC.
> So the right way is creating one build directory for each SOC, then 
> bitbake each output's recipe,
> right?
>
> I am also not sure if I can put the SDK and board image in the same 
> build directory. Because
> once I build a board's image after creating its SDK, I add gdbserver 
> to it, but the build fail without
> really building the gdbserver package. So I guess the board image 
> build is confused by the SDK
> build state.
>
> So the conclusion is I need a recommended way to separate output into 
> different build directories:
> 1. minimize rebuild shared packages
> 2. no build state corruption
> 3. if multi output in the same build dir, no change to conf/ files or 
> an easy way to switch between
>
> Regards,
> Qiang
>
>
>