Stockfish for Cartesi RISC-V Machine Emulator

This branch contains patchlets to compile a RISC-V 64-bit build of stockfish to run under the Cartesi machine emulator.

Setup Cartesi SDK

Build using Cartesi GCC. I just copied them from the docker build and put them in my path (outside of the docker). It's probably easiest to build in the SDK docker.

git clone --recursive https://github.com/cartesi/machine-emulator-sdk

You should be able to run this command OK before proceeding:

riscv64-cartesi-linux-gnu-gcc --version

Build

Note, the Makefile kludge disables things like "tests".

Run this to build stockfish binary for riscv64 using Cartesi GCC toolchain:

git clone https://spacecruft.org/deepcrayon/stockfish
cd stockfish/src
make -j build ARCH=riscv64 COMP=riscv64-cartesi-linux-gnu-gcc COMPCXX=riscv64-cartesi-linux-gnu-g++

Build Disk Images for Cartesi Emulator

# Go back to top level directory in this git repo:
cd ..

# Copy newly built stockfish for cartesi disk image:
cp -p src/stockfish cartesi/img/stockfish

# Make 64 megabyte ext2 disk image with stockfish and shell script
genext2fs -b 51200 -d cartesi/img cartesi/stockfish.ext2

Run Stockfish in Emulator

To run the disk images, using upstream rootfs:

cartesi-machine								\
	--ram-length=256Mi						\
	--flash-drive=label:stockfish,filename:cartesi/stockfish.ext2	\
	--flash-drive=label:root,filename:/opt/cartesi/share/images/rootfs.ext2	\
	-- /mnt/stockfish/stockfish.sh

Emulator Output

This takes ~3 minutes to run:

         .
        / \
      /    \
\---/---\  /----\
 \       X       \
  \----/  \---/---\
       \    / CARTESI
        \ /   MACHINE
         '


Stockfish running under Cartesi virtual machine

Stockfish 161121 by the Stockfish developers (see AUTHORS file)

option name Debug Log File type string default 
option name Threads type spin default 1 min 1 max 512
option name Hash type spin default 16 min 1 max 33554432
option name Clear Hash type button
option name Ponder type check default false
option name MultiPV type spin default 1 min 1 max 500
option name Skill Level type spin default 20 min 0 max 20
option name Move Overhead type spin default 10 min 0 max 5000
option name Slow Mover type spin default 100 min 10 max 1000
option name nodestime type spin default 0 min 0 max 10000
option name UCI_Chess960 type check default false
option name UCI_AnalyseMode type check default false
option name UCI_LimitStrength type check default false
option name UCI_Elo type spin default 1350 min 1350 max 2850
option name UCI_ShowWDL type check default false
option name SyzygyPath type string default <empty>
option name SyzygyProbeDepth type spin default 1 min 1 max 100
option name Syzygy50MoveRule type check default true
option name SyzygyProbeLimit type spin default 7 min 0 max 7
option name Use NNUE type check default true
option name EvalFile type string default nn-13406b1dcbe0.nnue
uciok

Halted
Cycles: 3142947347

Store Machine State

Instead of fully booting, a RAM image can be loaded and the CPU set to a cycle, such as 3142947347.

cartesi-machine								\
	--max-mcycle=3142947347						\
	--store=cartesi/stockfish-ram					\
	--ram-length=256Mi						\
	--flash-drive=label:stockfish,filename:cartesi/stockfish.ext2	\
	--flash-drive=label:root,filename:/opt/cartesi/share/images/rootfs.ext2	\
	-- /mnt/stockfish/stockfish.sh

TODO

• Make image of RAM with stockfish already run once and loaded.

• Fix tests.

Upstream

See:

• README-upstream.md

• https://github.com/official-stockfish/Stockfish

• https://stockfishchess.org/

Cartesi

See:

• https://cartesi.io/en/docs/intro/

• https://github.com/cartesi/machine-emulator/

Copying

Same as upstream Stockfish, GPL v3.

Contact

# y@deepcrayon.fish or jebba in Cartesi/Stockfish discord