Gigabyte has posted the source tarballs, and they seem complete (just downloading it, 90-100Mb each).
All Linux based Gigabyte router has the GPL link, and new kits will be shipped with the GPL license on the cd. Source code will be available on the homepage.
http://tw.giga-byte.com/Communication/Products/Gigabyte_GPL_V1.0.pdf
Thank You, Gigabyte.