[yocto] Build Time Update

[Richard Purdie]

Just to update on build time at the moment, we did regress pretty badly
recently. I'm fairly sure this was down to a useradd change which meant
dbus-native was depending on a target package and holding up a
significant portion of the build and this has been fixed.

I just did a build of a qemuarm "core-image-sato" on my 12 way system in
43 minutes. I usually benchmark qemux86 which was at around 51 minutes
for the same configuration. I suspect the recent pseudo and libtool
linking changes have given us some good speedups.

More work remains but we have made some good progress there!

Cheers,

Richard