which version of riscv-tools for testing the Rocket without FPU on ZYBO FPGA?

[zhongpanwu]

Hi, I am trying to run the a real simple Rocket (an early version issued in 2016, and It is RV64IMA rather than RV64G) emulation on the FPGA, but I could not find the correct version of the tools including fesvr, riscv-compiler and pk. I followed the section G ( Building riscv-tools for Zybo) in this webpage: https://github.com/ucb-bar/fpga-zynq#zybotools. Howerver, the version of the tool is lost and the manner mentioned is not working. So I just want to get any help here, and many thanks in advance for any comments.

[jim-wilson]

Use -march=rv64ima when compiling. However, there is the usual problem that precompiled libraries won't be available unless you built a multilib for that configure. So in general it is best to use --with-arch=rv64ima when configuring so that the libraries will be rv64ima also.

If this is an old version of the ISA, then it might not match the support implemented by the current versions of the tools. There hasn't been much change to the unpriv ISA so it will probably work, but you will almost certainly run into priv ISA issues as there have been backward compatible breaking changes several times. To get support for an old ISA you might need to use old versions of the tools. The tools are in git, so there is history going back a number of years. You can try checking out old versions from 2016 to see if they work better. I don't know how easy they are to compile though. No one has checked in a long time.