Most Intel BSPs are located under http://git.yoctoproject.org/cgit/cgit.cgi/meta-intel/tree/?h=daisy
However the Edison sources are currently handled differently.
I have however, started a thread attempting to get Intel to start participating in up-streaming to the yocto project:
Currently, the Edison image src comes from https://communities.intel.com/docs/DOC-23242
Those are no other official sources I'm aware of.
For now I just dumped edision-src*ww42-14.tgz into https://github.com/instantinfrastructure/edison-src
Might want to take a look at the Intel® Edison BSP User Guide
Thank you, all!
I used the ping tool of ChinaZ to check those mirrors, and I have found that they are faster in North America but much slower in Asia. Maybe this issue affected the download.
I have downloaded for a whole day in a much slower rate. But soon after I posted this in the forum the Internet gets much more faster. :-D Because that was early morning in China. Thanks to the early morning.