[yocto] Configuring a layer to support multiple targets

[Bruce Ashfield]

On 11-08-17 03:59 AM, Chris Tapp wrote:
> On 13 Aug 2011, at 02:22, Bruce Ashfield wrote:
>
>> What's your yocto release / base kernel ? IF you happen to
>> be using linux-yocto there are several ways to avoid using
>> defconfigs at all, and share your common base of kernel
>> configuration items.
>
> Plan is to move to linux-yocto (currently using wrs). How do I configure
> it without using a defconfig?

I depends on how you host your BSP, and the release. In
yocto 1.1, there's new functionality that makes it easier
to graft a BSP onto the tree without needing to have the
BSP merged somewhere.

But to configure and work without a defconfig, you simply
need a BSP that branches from yocto/standard/base. Even the
autogenerated descriptions in 1.0 will automatically include
the standard kernel configs and settings and pass them to
your BSP. Once this is in place, you simply need a config
fragment (a .cfg file) for your board that adds/modifies the
base configuration.

>
> Also, is it possible to use a .config rather than a defconfig? I've got
> a lot of stuff turned off to reduce the size of the kernel, but a
> defconfig doesn't quite do. For example, if I have
>
> # CONFIG_USB_SERIAL is not set
>
> in a defconfig, then this gets in to the .config at build time. However,
> this doesn't disable any dependencies that are enabled in linux-wrs.
> This means that modules for the likes of the ftdi and pl2303 USB serial
> devices are still included in the kernel image.
>
> The use of a complete .config would stop this.

In this sense, the defconfig is simply a name to trigger
specific processing. Just capture and call your .config
'defconfig' and you'll get a translation of those settings
into the build.

Bruce

>
>
> Chris Tapp
>
> opensource at keylevel.com
> www.keylevel.com
>
>
>
> _______________________________________________
> yocto mailing list
> yocto at yoctoproject.org
> https://lists.yoctoproject.org/listinfo/yocto