Since I received my HiFive1 on March 20, I've been working hard to add support for RISC-V and the HiFive1 to my Forth target compiler system, muforth.
There are pieces missing still, but today it's possible to connect via
openocd, dump memory, disassemble code, and write and run bits of assembler and Forth code, all interactively, using only muforth. No need for GCC, binutils, or GDB!
If you want to try it out, I've written up instructions for getting starting with RISC-V and muforth.