As part of closing out the Windows toolchain card, I've documented the binary build release process at: https://wiki.linaro.org/WorkingGroups/ToolChain/BinaryBuild/ReleaseProcess
The interesting thing is a script that pulls builds from S3 and posts them to Launchpad. There's a curl command at the end that does the upload and might be useful.
-- Michael
linaro-toolchain@lists.linaro.org