Build the Toolchain
From Rigol Homebrew Wiki
Sorry, not complete yet...
Download the Toolchain from https://github.com/krater/rigol-toolchain
and follow the instructions in the README file...
build essentials + git
Installing the Blackfin toolchain
Just follow the instructions here to install the bfin-uclinux package.
Download and install Rigol toolchain
Then: Patch_your_Firmware