[yocto] tar ball vs. git development questions

[Gary Thomas]

On 2012-01-22 13:19, James Abernathy wrote:
> I have used both git and the tarball methods of bitbaking projects, all of them derivatives of the examples in the Yocto documentation. I was having issues using the local clone of
> the Yocto kernel git repository this weekend. I had successfully done that before, but I was rebuilding the PC workstation, and getting everything setup and tested some of the
> meta-intel BSPs to make sure I had everything right. Cloning the linux-yocto-3.0 repository was successful, but the bakes against it failed. I made sure I had poky-extras setup
> right, but I still had problems. To isolate the problem, I changed to building with the tarballs and everything worked fine.
>
> So that got me thinking what are the differences between the 2 methods:
>
>   * I assume that if I use the tarball method, bitbake, using the recipes, pulls down files from the online repositories and puts those files into the centralized local download
>     directory ($DL_DIR), allowing reuse instead of re-downloading each time. The content downloaded for linux-yocto-3.0 is exactly what would be pulled from the local repository if
>     I used a local clone of the git repository for linux-yocto-3.0.
>   * If my assumption above is correct, if I'm not modifying the source code of the kernel (only changing config parameters), then once you've run at least one build with the
>     tarball method, the $DL_DIR directory contains all the files you'll need to build any image with linux-yocto-3.0. So there is no need to have a local clone of the kernel
>     repository for speeding up development. Am I right?
>   * If I have a successful creation of a bare clone of linux-yocto-3.0.git, how could builds of Edison packages be failing? That makes me concerned about using git and successfully
>     repeating builds of stable branches like Edison.

If you set BB_GENERATE_MIRROR_TARBALLS = "1" (e.g. in local.conf)
then you'll get tarballs which hold the git repositories after
download.  You can then reuse these (by sharing the DL_DIR or
using a local mirror).  Does that help with the issue you're seeing?

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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