The first cross-compiler toolset(s) to be used are published here:
Those files are also mirrored here:
With the README.txt renamed to include the release date.
Unlike the MG/CS tool chains, there is no six month wait for these tool chains, they are released (updated) monthly.
Ubuntu is using the Linaro tool chains, so they do have a few miles on them in actual use.
(Yeah, like you go out and cross-compile 18,000 packages - see if your compiler craps out.)
Users need to read the README -
The default code output is VFPv3-D16+Neon for the cortex-9.
So always pass-in the compiler options appropriate for your target processor.