[yocto] Adding ALSA to the Yocto SDK

[Patrick Turley]

I've been working on re-targeting some code from a vendor's board to our own board.

For libraries and other low-level code, everything's been fine. For test applications, I'm running into a dependency on the header file alsa/asoundlib.h, which is obviously part of ALSA.

I've been building our SDK with:

    bitbake meta-toolchain-sdk

This gives us most everything we need, but it does *not* include header files and libraries for ALSA. That actually seems perfectly reasonable to me -- not everyone needs ALSA support in their applications, so the *default* SDK shouldn't be burdened with that.

We *do* need it. As I see it, there are two possibilities:

1) There's something I can do that will cause OE/Yocto to include ALSA header files in the SDK I produce. If that's the case, can you tell me what I need to do?

2) The ALSA header files aren't *supposed* to be in the SDK -- I'm supposed to be delivering them to the compilation process in another way. If that's the case, can you tell me what I need to do?


Other items of note…

-- Executing "bitbake alsa-lib" *did* put the expected files within our sysroot (under tmp/sysroots). Even so (as we intuitively expected) executing "bitbake meta-toolchain-sdk" afterward did *not* put them into the SDK. We conclude that having a package built and available for the SDK doesn't necessarily get it into the SDK.

-- Adding ALSA to our image also caused the correct files to end up in our sysroot but, again, nothing appeared in the SDK. We conclude that the contents of the image do *not* dictate the contents of the SDK.