[gluxon]

Yes, of course. GCC is licensed GPLv3. Because of that, you could even sell NI's distribution of GCC. (Don't do that though. That would be evil.)

Edit: I forgot something. vxWorks is trademarked by NI. This means that NI is the only legal distributor of vxWorks binaries/source. You should be legally fine as long as you don't make modifications, so mirroring is ok.