assembly.riscv.md

C++ links: RISC-V Assembly

Note: see Computer Architecture -- recommended background (which makes the following significantly more approachable) includes an undergraduate-level course.

• RISC-V Foundation
  • https://riscv.org/
  • https://github.com/riscv
  • https://riscv.org/mailing-lists/
  • https://riscv.org/category/workshops/proceedings/

Contents

• Readings: Books, Security
• Formalization, Specification, Verification
• Open-Source Hardware Projects
• References
• Software: Binary Analysis, Emulation & Simulation, Security
• Talks
• Tutorials

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Readings

https://riscv.org/publications/

• A Bug-Free RISC-V Core without Simulation - https://tomverbeure.github.io/risc-v/2018/11/19/A-Bug-Free-RISC-V-Core-without-Simulation.html
• A Highly Productive Implementation of an Out-of-Order Processor Generator
  • 2018 PhD Thesis; Christopher Celio
  • https://www2.eecs.berkeley.edu/Pubs/TechRpts/2018/EECS-2018-151.html
• A Survey of the RISC-V Architecture Software Support
  • IEEE Access 10 (2022)
  • Benjamin W. Mezger, Douglas A. dos Santos, Luigi Dilillo, Cesar A. Zeferino, Douglas R. Melo
  • https://dx.doi.org/10.1109/ACCESS.2022.3174125
• An Agile Approach to Building RISC-V Microprocessors - https://people.eecs.berkeley.edu/~bora/Journals/2016/IEEEMicro16.pdf
• CARRV: Workshop on Computer Architecture Research with RISC-V - https://carrv.github.io/
• Design of the RISC-V Instruction Set Architecture - http://www.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-1.html
• GRVI Phalanx: A Massively Parallel RISC-V FPGA Accelerator Accelerator - https://arxiv.org/abs/1606.01037
• How Genode came to RISC-V - https://genode.org/documentation/articles/riscv
• Instruction Sets Should Be Free: The Case For RISC-V - https://www.eecs.berkeley.edu/Pubs/TechRpts/2014/EECS-2014-146.html
• ISA Semantics for ARMv8-A, RISC-V, and CHERI-MIPS - https://alastairreid.github.io/papers/POPL_19/
• Proprietary versus Open Instruction Sets - http://research.cs.wisc.edu/multifacet/papers/ieeemicro16_card_isa.pdf
• RISC-V development plans - https://groups.google.com/a/groups.riscv.org/d/msg/isa-dev/sUQk6pFG0eA/AGNF44e4AAAJ
• RISC-V Geneology - https://www.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-6.html
• RISC-V International Conference Proceedings - http://rise.cse.iitm.ac.in/ric2017/index.html#Proceedings
• RISC-V Offers Simple, Modular ISA - https://riscv.org/2016/04/risc-v-offers-simple-modular-isa/
• rv8: a high performance RISC-V to x86 binary translator
  • https://anarch128.org/~mclark/rv8-carrv.pdf
  • https://carrv.github.io/papers/clark-rv8-carrv2017.pdf
• Surveying the Free and Open Source RISC-V Ecosystem – Embecosm
  • https://www.embecosm.com/2018/05/07/surveying-the-free-and-open-source-risc-v-ecosystem/
• The Adventures of OS: Making a RISC-V Operating System using Rust
  • https://osblog.stephenmarz.com/
• The Berkeley Out-of-Order Machine (BOOM): An Industry-Competitive, Synthesizable, Parameterized RISC-V Processor
  • https://www.eecs.berkeley.edu/Pubs/TechRpts/2015/EECS-2015-167.html
  • BOOM v2: an open-source out-of-order RISC-V core - https://www2.eecs.berkeley.edu/Pubs/TechRpts/2017/EECS-2017-157.html
• The Case for Open Instruction Sets - http://www.linleygroup.com/mpr/article.php?id=11267
• The Renewed Case for the Reduced Instruction Set Computer: Avoiding ISA Bloat with Macro-Op Fusion for RISC-V
  • https://arxiv.org/abs/1607.02318
  • https://www.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-130.html
• The VexRiscV CPU - A New Way to Design - https://tomverbeure.github.io/rtl/2018/12/06/The-VexRiscV-CPU-A-New-Way-To-Design.html
• Towards a High-Performance RISC-V Emulator
  • WSCAD 2018
  • Leandro Lupori, Vanderson Martins do Rosario, Edson Borin
  • https://www.researchgate.net/publication/328314631_Towards_a_High-Performance_RISC-V_Emulator
  • https://www.researchgate.net/profile/Vanderson_Rosario2/publication/328314631_Towards_a_High-Performance_RISC-V_Emulator/links/5bc5e1ec458515f7d9bf6342/Towards-a-High-Performance-RISC-V-Emulator.pdf

Readings: Performance

• RISC-V Optimization Guide
  • https://gitlab.com/riseproject/riscv-optimization-guide
• Supporting RISC-V Performance Counters through Performance analysis tools for Linux (Perf)
  • CARRV 2021
  • Joao Mario Domingos, Pedro Tomas, Leonel Sousa
  • https://arxiv.org/abs/2112.11767

Readings: Security

• Return-Oriented Programming on RISC-V
  • 2020 ACM Asia Conference on Computer and Communications Security (AsiaCCS)
  • Georges-Axel Jaloyan, Konstantinos Markantonakis, Raja Naeem Akram, David Robin, Keith Mayes, David Naccache
  • https://doi.org/10.1145/3320269.3384738

Books

https://riscv.org/risc-v-books/

• "Computer Organization and Design: The Hardware Software Interface: RISC-V Edition" by David A. Patterson, John L. Hennessy (2017)
  • http://store.elsevier.com/product.jsp?isbn=9780128122754
• "The RISC-V Reader: An Open Architecture Atlas" by David Patterson, Andrew Waterman (2017)
  • http://www.riscvbook.com/

Concurrency

• The Semantics of Multicopy Atomic ARMv8 and RISC-V
  • 2019 PhD dissertation; Christopher Pulte
  • https://doi.org/10.17863/CAM.39379

Instruction Set Architecture

• RISC-V Register Files
  • https://fprox.blogspot.com/2022/10/risc-v-register-files.html
• Adding custom instructions in the RISC-V ISA
  • https://pcotret.gitlab.io/riscv-custom/
• RISC-V Assembler Cheat Sheet
  • https://projectf.io/posts/riscv-cheat-sheet/
• RISC-V ISA online string decoder
  • https://rv.drom.io/
  • https://github.com/drom/rv
• rvcodec.js: a RISC-V instruction encoder/decoder
  • shows how each token of the assembly instruction is encoded as part of the binary representation
  • https://gitlab.com/luplab/rvcodecjs/
  • https://luplab.gitlab.io/rvcodecjs/

Instruction Set Architecture: Encoding

• Basic Shellcode in RISC-V Linux
  • Thomas Karpiniec
  • https://thomask.sdf.org/blog/2018/08/25/basic-shellcode-in-riscv-linux.html
• Emoji shellcoding in RISC-V
  • IEEE Workshop on Offensive Technologies (WOOT) 2023
  • Hadrien Barral, Georges-Axel Jaloyan, David Naccache
  • https://wootconference.org/papers/woot23-paper5.pdf
  • https://github.com/RischardV/emoji-shellcoding
• RISC-V: #AlphanumericShellcoding
  • USENIX Workshop on Offensive Technologies (WOOT) 2019; DEF CON 27 (2019)
  • Hadrien Barral, Rémi Géraud-Stewart, Georges-Axel Jaloyan, David Naccache
  • https://www.usenix.org/conference/woot19/presentation/barral
  • https://xn--fda.fr/riscv-alphanumeric-shellcoding/defcon27_riscv-alphanumeric-shellcoding.pdf
  • https://github.com/RischardV/riscv-alphanumeric-shellcoding
• RISC-V Shellcoding Cheatsheet
  • Christina Quast
  • https://pagedout.institute/download/PagedOut_002_beta2.pdf#page=57
  • http://shell-storm.org/shellcode/files/shellcode-908.php
  • https://github.com/chrysh/riscv_exploitation

Instruction Set Architecture: Extensions

• RISC-V Compressed Instructions (part 2): Zc extensions
  • https://fprox.blogspot.com/2022/12/riscv-compressed-zc-extensions.html

Instruction Set Architecture: Extensions: Bit Manipulation

• RISC-V Scalar Bit Manipulation Extensions
  • 2024-04-08
  • Zba (address generation), Zbb (basic bit manipulation), Zbc (carry-less multiplication), Zbs (single-bit manipulation), Zbkb (bit manipulation for cryptography), Zbkc (carry-less for cryptography), Zbkx (crossbar permutations), B Standard Extension for Bit Manipulation Instructions (Zba, Zbb, Zbs)
  • https://fprox.substack.com/p/risc-v-scalar-bit-manipulation-extensions

Instruction Set Architecture: Extensions: C Standard Extension for Compressed Instructions

• RISC-V Compressed Instructions (part 1): C extension
  • https://fprox.blogspot.com/2022/12/riscv-c-extension.html

Instruction Set Architecture: Extensions: Cryptography

• RISC-V Vector Cryptography Extensions (1/2)
  • 2023-02-12
  • https://fprox.substack.com/p/risc-v-vector-cryptography-extensions
• RISC-V Vector Cryptography Extensions (2/2)
  • 2023-02-20
  • https://fprox.substack.com/p/risc-v-vector-cryptography-extension
• RISC-V vector crypto spec freeze update
  • 2023-06-25
  • https://fprox.substack.com/p/risc-v-vector-crypto-spec-freeze

Instruction Set Architecture: Extensions: V Vector Extension

• riscv-v-spec: Working draft of the proposed RISC-V V vector extension
  • https://github.com/riscv/riscv-v-spec
• Programming with RISC-V Vector Instructions
  • https://gms.tf/riscv-vector.html
• RISC-V Vector benchmarks
  • https://github.com/camel-cdr/rvv-bench
• RISC-V Vector Extension in a Nutshell
  • https://fprox.substack.com/p/risc-v-vector-in-a-nutshell
  • Part 1: Introduction
    • https://fprox.blogspot.com/2022/07/risc-v-vector-extension-in-nutshell.html
  • Part 2: Arithmetic and Logic Instructions
    • https://fprox.blogspot.com/2022/08/risc-v-vector-extension-in-nutshell.html
  • Part 3: Masks
    • https://fprox.blogspot.com/2022/08/risc-v-vector-extension-in-a-nutshell-part-3.html
  • Part 4: permute operations
    • https://fprox.blogspot.com/2022/08/isc-v-vector-extension-in-nutshell-part4.html
  • Part 5.1: vector loads and stores: Simple, strided, and segmented memory operations
    • https://fprox.blogspot.com/2022/09/riscv-vector-extension-part5-1-load-store-memory.html
  • Part 5.2: vector loads and stores: Indexed memory operations, whole register instructions, managing faults during vector memory operations
    • https://fprox.blogspot.com/2022/09/riscv-vector-extension-part5-2-load-store-memory.html
  • How to read a RISC-V Vector assembly instruction
    • https://fprox.substack.com/p/how-to-read-risc-v-vector-assembly
  • RISC-V Vector Register Groups
    • https://fprox.substack.com/p/risc-v-vector-register-groups
  • RISC-V Vector Element Groups
    • https://fprox.substack.com/p/risc-v-vector-element-groups
• RISC-V Vector Programming in C with Intrinsics
  • 2023-11-23
  • https://fprox.substack.com/p/risc-v-vector-programming-in-c-with
• RVV implementation of Keccak / SHA-3 (part 1)
  • Leveraging RISC-V Vector to slow down SHA-3 software implementation
  • 2023-12-31
  • https://fprox.substack.com/p/rvv-implementation-of-keccak-sha
• Implementing Softmax using RISC-V Vector
  • Quick and dirty method to implement a vectorized non-linear function using RVV
  • 2024-02-12
  • https://fprox.substack.com/p/implementing-softmax-using-risc-v
• Transposing a Matrix using RISC-V Vector
  • Survey of basic techniques to transform matrix layouts using RVV
  • 2024-01-09
  • https://fprox.substack.com/p/transposing-a-matrix-using-risc-v
• When LLVM scalable vector meets RISC-V: RVVBitsPerBlock
  • 2024-10-05
  • Min-Yih Hsu
  • https://myhsu.xyz/llvm-riscv-bits-per-block/

Instruction Set Architecture: Extensions: "Zfa" Standard Extension for Additional Floating-Point Instructions

• Zfa: even more floating-point operations
  • 2023-05-24
  • https://fprox.substack.com/p/zfa-even-more-floating-point-operations

Instruction Set Architecture: Profiles

• RISC-V Profiles: Defining sets of extensions for coherent ecosystems
  • 2023-03-22
  • https://fprox.substack.com/p/risc-v-profiles
• Sneak peek at RISC-V RVA23(U64) profile
  • 2023-02-26
  • https://fprox.substack.com/p/risc-v-profile-rva23u64

Simulation

• Flexible Timing Simulation of RISC-V Processors with Sniper
  • Computer Architecture Research with RISC-V (CARRV) 2018
  • Neethu Bal Mallya, Cecilia Gonzalez-Alvarez, Trevor E. Carlson
  • https://carrv.github.io/2018/papers/CARRV_2018_paper_7.pdf
• High-performance RISC-V emulation
  • 2019 Master's Thesis; Leandro Lupori
  • http://repositorio.unicamp.br/handle/REPOSIP/334082?locale=en
  • RISC-V Static Binary Translator (SBT)
    • https://github.com/OpenISA/riscv-sbt
• Simulation of RISC-V based Systems in gem5
  • 2018 Diploma Thesis (Dipl.-Ing.); Robert Schefel
  • https://cfaed.tu-dresden.de/files/Images/people/chair-cc/theses/1808_Scheffel.pdf
• Verifying Instruction Set Simulators using Coverage-guided Fuzzing
  • Design, Automation & Test in Europe Conference & Exhibition (DATE) 2019
  • Vladimir Herdt, Daniel Große, Hoang M. Le, Rolf Drechsler
  • http://www.informatik.uni-bremen.de/agra/doc/konf/2019DATE_Verifying_Instruction_Set_Simulators_using_Coverage-guided_Fuzzing.pdf
  • http://www.informatik.uni-bremen.de/agra/systemc-verification/riscv-vp.html

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Formalization, Specification, Verification

• End-to-End Formal Verification of a RISC-V Processor Extended with Capability Pointers
  • FMCAD 2021
  • Dapeng Gao, Tom Melham
  • http://hdl.handle.net/20.500.12708/18622
  • https://youtube.com/watch?v=u6XT3OCOIcc
  • https://fmcad.org/FMCAD21/slides/end-to-end-verif.pdf
  • Capability Hardware Enhanced RISC Instructions (CHERI)
    • https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/
  • CHERI-modified versions of the Flute processor
    • https://github.com/CTSRD-CHERI/Flute
• Experimental_RISCV_Feature_Model
  • An experimental DSL to describe the full feature list of a RISC-V implementation, along with constraints on features and between features
  • https://github.com/rsnikhil/Experimental_RISCV_Feature_Model
• FORCE-RISCV
  • FORCE-RISCV is an instruction sequence generator (ISG) for the RISC-V instruction set architecture. It can be used to generate tests for design verification of RISC-V processors.
  • https://github.com/openhwgroup/force-riscv
• GRIFT: Galois RISC-V ISA Formal Tools
  • https://github.com/GaloisInc/grift
• ISA Semantics for ARMv8-A, RISC-V, and CHERI-MIPS
  • POPL 2019
  • Alasdair Armstrong, Thomas Bauereiss, Brian Campbell, Alastair Reid, Kathryn E. Gray, Robert M. Norton, Prashanth Mundkur, Mark Wassell, Jon French, Christopher Pulte, Shaked Flur, Ian Stark, Neel Krishnaswami, Peter Sewell
  • https://www.cl.cam.ac.uk/~pes20/sail/
  • http://www.cl.cam.ac.uk/users/pes20/sail/sail-popl2019.pdf
  • talk; https://dl.acm.org/citation.cfm?doid=3302515.3290384&preflayout=flat#formats
• KRISC-V: Semantics of RISC-V in K
  • an executable formal semantics of the RISC-V ISA using the K framework
  • unprivileged RV32E base ISA
  • https://github.com/runtimeverification/riscv-semantics
• L3 Specification of the RISC-V ISA - https://github.com/SRI-CSL/l3riscv
• RISC-V Architectural Self Checking Tests
  • https://github.com/tenstorrent/riscv_arch_tests
• RISC-V Formal Verification Framework - https://github.com/cliffordwolf/riscv-formal
• RISC-V ISA Formal Spec in BSV (Bluespec SystemVerilog) - https://github.com/rsnikhil/RISCV_ISA_Formal_Spec_in_BSV
• RISC-V Litmus Tests
  • RISC-V architecture concurrency model litmus tests
  • https://github.com/litmus-tests/litmus-tests-riscv
• RISC-V Sail ISA model
  • https://github.com/rems-project/sail-riscv
  • A Tour of the RISC-V ISA Formal Specification
    • https://github.com/rsnikhil/RISCV_ISA_Spec_Tour
• riscv-avs: RISC-V Architecture Verification Suite (AVS)
  • https://github.com/ispras/riscv-avs
  • an open test suite for RISC-V microprocessors
  • Each test is a program (in assembly or C) equipped with additional information: a test purpose description, an instruction describing how to generate a program (if applicable), a test coverage report, etc.
• RISCV-DV: a SV/UVM based open-source instruction generator for RISC-V processor verification
  • https://github.com/google/riscv-dv
• riscv-fs: F# RISC-V Instruction Set formal specification
  • https://github.com/mrLSD/riscv-fs
• RISCV-ISA-Spec: Formal specification of RISC-V Instruction Set - https://github.com/rsnikhil/RISCV-ISA-Spec
• riscv-coq: RISC-V Specification in Coq - https://github.com/mit-plv/riscv-coq
• riscv-semantics: formal specification of the RISC-V ISA written in Haskell - https://github.com/mit-plv/riscv-semantics
• RiscvSpecFormal: Formal Specification of RISC-V ISA in Kami
  • https://github.com/sifive/RiscvSpecFormal
• RMEM - relaxed-memory concurrency
  • a tool for exploring the relaxed-memory concurrency for ARM, POWER, RISC-V, and x86
  • help page: http://www.cl.cam.ac.uk/~sf502/regressions/rmem/help.html
  • web interface: http://www.cl.cam.ac.uk/users/pes20/rmem/

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Open-Source Hardware Projects

• RISC-V Cores and SoC Overview - https://github.com/riscv/riscv-cores-list
• Taxonomy of Open Source Processors - http://parallel.princeton.edu/openpiton/open_source_processors.php
• A Comparative Survey of Open-Source Application-Class RISC-V Processor Implementations
  • ACM International Conference on Computing Frontiers (CF) 2021
  • Alexander Dörflinger, Mark Albers, Yejun Guan, Benedikt Kleinbeck, Harald Michalik, Raphael Klink, Chistopher Blochwitz, Anouar Nechi, Mladen Berekovic
  • https://dl.acm.org/doi/10.1145/3457388.3458657

• BlackParrot (SystemVerilog)
  • Linux-capable cache-coherent, RV64GC multicore
  • https://github.com/black-parrot
  • BlackParrot: An Agile Open Source RISC-V Multicore for Accelerator SoCs
    • FOSDEM 2020; Dan Petrisko
    • https://fosdem.org/2020/schedule/event/riscv_blackparrot/
• BOOM: The Berkeley Out-of-Order RISC-V Processor (Chisel)
  • https://ccelio.github.io/riscv-boom-doc/
  • https://github.com/ucb-bar/riscv-boom
  • https://twitter.com/boom_cpu
• core-v-wally: Configurable RISC-V Processor (SystemVerilog)
  • https://github.com/openhwgroup/cvw
  • Wally is a 5-stage pipelined processor configurable to support all the standard RISC-V options, incluidng RV32/64, A, C, F, D, and M extensions, FENCE.I, and the various privileged modes and CSRs. It is written in SystemVerilog. It passes the RISC-V Arch Tests and boots Linux on an FPGA.
• CVA6 RISC-V CPU (SystemVerilog)
  • application class, 6-stage, single issue, in-order CPU, implements the 64-bit RISC-V instruction set, capable of booting Linux
  • https://github.com/openhwgroup/cva6
  • https://docs.openhwgroup.org/projects/cva6-user-manual/
  • https://pulp-platform.org/docs/Ariane_detailed.pdf
• DarkRISCV: open-source RISC-V CPU core implemented in Verilog from scratch in one night! (Verilog)
  • https://github.com/darklife/darkriscv
• Davis In-Order (DINO) CPU models (Chisel)
  • A teaching-focused RISC-V CPU design used at UC Davis
  • https://github.com/jlpteaching/dinocpu
  • The Davis In-Order (DINO) CPU: A Teaching-focused RISC-V CPU Design
    • Workshop on Computer Architecture Education (WCAE) 2019
    • Jason Lowe-Power and Christopher Nitta
    • Paper: https://arch.cs.ucdavis.edu/assets/papers/wcae19-dinocpu.pdf
    • Slides: https://arch.cs.ucdavis.edu/assets/papers/wcae19-dinocpu-presentation.pdf
• engine-V: SoftCPU/SoC engine-V (Verilog)
  • https://github.com/micro-FPGA/engine-V
• f32c - A 32-bit RISC-V / MIPS retargetable CPU core (VHDL)
  • https://github.com/f32c/f32c
• FemtoRV: a minimalistic RISC-V CPU (Verilog)
  • Learning FPGA, yosys, nextpnr, and RISC-V
  • FemtoRV is a minimalistic RISC-V design, with easy-to-read Verilog sources (less than 1000 lines), directly written from the RISC-V specification. It includes a companion SOC, with drivers for an UART, a led matrix, a small OLED display, SPI RAM and SDCard. Its most basic configuration fits on the Lattice IceStick (< 1280 LUTs). It can be used for teaching processor design and RISC-V programming.
  • https://github.com/BrunoLevy/learn-fpga
• FWRISC: a Featherweight RISC-V implementation of the RV32I instruction set
  • https://github.com/mballance/fwrisc
  • FWRISC: Sizing up the RISC-V Architecture
    • https://bitsbytesgates.blogspot.com/2018/12/fwrisc-sizing-up-risc-v-architecture.html
• HammerBlade RISC-V Manycore (SystemVerilog)
  • A programmable, scalable RISC-V fabric
  • https://github.com/bespoke-silicon-group/bsg_bladerunner
  • https://github.com/bespoke-silicon-group/bsg_manycore
  • http://bjump.org/manycore/
  • HammerBlade IR: https://capra.cs.cornell.edu/hbir/
  • FOSDEM 2020; Michael Taylor
    • https://fosdem.org/2020/schedule/event/riscv_hammerblade/
• HL5: A 32-bit RISC-V Processor Designed with High-Level Synthesis (SystemC)
  • https://github.com/sld-columbia/hl5
  • Custom Integrated Circuits Conference (CICC) 2020
    • Paolo Mantovani, Robert Margelli, Davide Giri, Luca P. Carloni
    • https://sld.cs.columbia.edu/pubs/mantovani_cicc20.pdf
• Ibex: a small 32 bit RISC-V CPU core (RV32IMC/EMC) with a 2-stage pipeline (SystemVerilog)
  • https://github.com/lowRISC/ibex/
  • https://www.lowrisc.org/blog/2019/06/an-update-on-ibex-our-microcontroller-class-cpu-core/
  • How lowRISC made its Ibex RISC-V CPU core faster: Using open source tools to improve an open source core
    • FOSDEM 2020; Greg Chadwick
    • https://fosdem.org/2020/schedule/event/riscv_lowrisc/
• Icicle: 32-bit RISC-V system on chip for iCE40 and ECP5 FPGAs (SystemVerilog)
  • https://github.com/grahamedgecombe/icicle
• lowRISC - creating a fully open-sourced, Linux-capable, RISC-V-based SoC (SystemVerilog)
  • http://www.lowrisc.org/
  • https://github.com/lowRISC/lowrisc-chip/
  • https://twitter.com/lowRISC
• mriscv: A 32-bit Microcontroller featuring a RISC-V core (Verilog)
  • http://www.onchipuis.io/risc-v
  • https://github.com/onchipuis/mriscv
  • https://github.com/onchipuis/mriscvcore
  • https://twitter.com/onchipUIS
• NekoIchi: A simple RISC-V CPU & GPU running on an Arty A7-100T FPGA board (SystemVerilog)
  • https://github.com/ecilasun/NekoIchi
  • NekoIchi Tutorials: the articles for each part of the RISC-V CPU & GPU series
    • https://github.com/ecilasun/nekoichiarticle
• NEORV32 Processor: A size-optimized, customizable full-scale 32-bit RISC-V soft-core CPU and SoC written in platform-independent VHDL
  • https://github.com/stnolting/neorv32
• ORCA - an implementation of RISC-V intended to target FPGAs (VHDL)
  • https://github.com/VectorBlox/orca
• PicoRV32 - A Size-Optimized RISC-V CPU (Verilog)
  • https://github.com/cliffordwolf/picorv32
• PULPino - 32-bit RISC-V microcontroller core (SystemVerilog)
  • http://www.pulp-platform.org/
  • https://github.com/pulp-platform/pulpino
  • https://twitter.com/pulp_platform
• PulseRain Reindeer: RISCV RV32I[M] Soft CPU (Verilog)
  • https://github.com/PulseRain/Reindeer
• RIDECORE (RIsc-v Dynamic Execution CORE) - Out-of-Order RISC-V processor (Verilog)
  • https://github.com/ridecore/ridecore
• RI5CY: RISC-V Core - PULP RI5CY core modified for Verilator modeling and as a GDB server (SystemVerilog)
  • https://github.com/embecosm/ri5cy
  • A dive into RI5CY core internals - https://www.embecosm.com/2019/08/13/a-dive-into-ri5cy-core-internals/
• RISC-V VHDL: System-on-Chip (VHDL)
  • VHDL implementation of the RISC-V System-on-Chip based on bare "Rocket Chip"
  • http://sergeykhbr.github.io/riscv_vhdl/
  • https://github.com/sergeykhbr/riscv_vhdl
• riscv-simple-sv: A simple RISC V core for teaching (SystemVerilog)
  • https://github.com/tilk/riscv-simple-sv
• Riscy Processors - Open-Sourced RISC-V Processors (Bluespec System Verilog)
  • https://github.com/csail-csg/riscy
• Rocket Chip Generator (Chisel)
  • https://github.com/ucb-bar/rocket-chip/
• RPU: Basic RISC-V CPU implementation in VHDL
  • https://github.com/Domipheus/RPU
  • Designing a RISC-V CPU (TPU/RPU) in VHDL Series
    • http://labs.domipheus.com/blog/tpu-series-quick-links/
• RSD: RISC-V Out-of-Order Superscalar Processor (SystemVerilog)
  • https://github.com/rsd-devel/rsd
  • An Open Source FPGA-Optimized Out-of-Order RISC-V Soft Processor
    • IEEE International Conference on Field-Programmable Technology (FPT) 2019
    • Susumu Mashimo, Akifumi Fujita, Reoma Matsuo, Seiya Akaki, Akifumi Fukuda, Toru Koizumi, Junichiro Kadomoto, Hidetsugu Irie, Masahiro Goshima, Koji Inoue, Ryota Shioya
    • http://sv.rsg.ci.i.u-tokyo.ac.jp/pdfs/Mashimo-FPT'19.pdf
• SCR1: an open-source RISC-V compatible MCU core (SystemVerilog)
  • https://github.com/syntacore/scr1
• SERV: The SErial RISC-V CPU (Verilog)
  • https://github.com/olofk/serv
• SHAKTI Processor Project (Bluespec System Verilog; generated Verilog)
  • http://rise.cse.iitm.ac.in/shakti.html
  • SHAKTI Tutorial at the VLSI Design Conference - http://www.slideshare.net/GSMadhusudan/shaktivlsidtutorial
  • https://bitbucket.org/casl/shakti_public
• SiFive's Freedom platforms RTL source files (Chisel)
  • https://github.com/sifive/freedom
• Sodor Processor Collection - educational microarchitectures (Chisel)
  • https://github.com/ucb-bar/riscv-sodor
• SweRV RISC-V core from Western Digital (SystemVerilog)
  • https://github.com/westerndigitalcorporation/swerv_eh1
• Taiga (SystemVerilog)
  • 32-bit RISC-V processor designed for FPGAs supporting the Multiply/Divide and Atomic extensions (RV32IMA)
  • https://gitlab.com/sfu-rcl/Taiga
  • TAIGA: A new RISC-V soft-processor framework enabling high performance CPU architectural features
    • Field Programmable Logic and Applications (FPL) 2017
    • E. Matthews and L. Shannon
    • https://doi.org/10.23919/FPL.2017.8056766
    • https://carrv.github.io/2017/papers/matthews-taiga-carrv2017.pdf
• VexRiscv: FPGA-friendly 32-bit RISC-V CPU implementation (SpinalHDL)
  • https://github.com/SpinalHDL/VexRiscv
• Vortex RISC-V GPGPU (SystemVerilog)
  • A full-system RISC-V-based GPGPU processor
  • RV32IMF
  • https://github.com/vortexgpgpu/vortex
• YARVI - Yet Another RISC-V Implementation (Verilog)
  • https://github.com/tommythorn/yarvi
  • https://www.cl.cam.ac.uk/teaching/1516/ECAD+Arch/exercise-yarvi.html

---

References

https://riscv.org/specifications/

• A RISC-V ELF psABI Document - RISC-V calling convention - https://github.com/riscv/riscv-elf-psabi-doc
• Calling Convention - http://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf
• Documentation for RISC-V Spike - https://github.com/poweihuang17/Documentation_Spike
• Intrinsics viewer
  • https://dzaima.github.io/intrinsics-viewer/
  • https://github.com/dzaima/intrinsics-viewer
• Notes on RISC-V assembly - https://www.imperialviolet.org/2016/12/31/riscv.html
• Reference Card - https://www.cl.cam.ac.uk/teaching/1617/ECAD+Arch/files/docs/RISCVGreenCardv8-20151013.pdf
• RISC-V Assembly Programmer's Manual - https://github.com/riscv/riscv-asm-manual/blob/master/riscv-asm.md
• riscv-calling-conv-model: work towards a "golden model" of the RISC-V calling convention(s) - https://github.com/lowRISC/riscv-calling-conv-model
• RISC-V Instruction Set Manual - https://github.com/riscv/riscv-isa-manual
• RISC-V Instruction Set Listing - https://github.com/michaeljclark/riscv-meta/blob/master/doc/pdf/riscv-instructions.pdf
• RISC-V Instruction Types - https://github.com/michaeljclark/riscv-meta/blob/master/doc/pdf/riscv-types.pdf
• RISC-V Instructions
  • riscv-instr-encoding spreadsheet: a compact overview of the available instructions, their grouping, the encoding, etc.
  • https://www.akkadia.org/drepper/risc-v-instructions.html
• RISC-V Reference Card: An unofficial reference sheet for RISC-V
  • https://github.com/jameslzhu/riscv-card
  • https://github.com/jameslzhu/riscv-card/blob/master/riscv-card.pdf
• RISC-V Toolchain Conventions - https://github.com/lowRISC/riscv-toolchain-conventions
• The Embedded RISC-V Project
  • A complementary RISC-V specification intended for bare metal embedded applications
  • https://emb-riscv.github.io/
  • https://github.com/emb-riscv
  • https://github.com/emb-riscv/specs-markdown
• The RISC-V Compressed Instruction Set Manual - https://riscv.org/specifications/compressed-isa/
• The RISC-V Instruction Set Manual, Volume I: User-Level ISA - https://riscv.org/specifications/
• The RISC-V Instruction Set Manual Volume II: Privileged Architecture - https://riscv.org/specifications/privileged-isa/
• Wikipedia: RISC-V - https://en.wikipedia.org/wiki/RISC-V

---

Software

https://riscv.org/software-tools/

• Compiler Explorer with RISC-V support - https://cx.rv8.io/
• Debian port - https://wiki.debian.org/RISC-V
• hpm_counters: A simple utility for doing RISC-V Hardware Performance Monitor (HPM) perf monitoring
  • https://github.com/ccelio/riscv-hpmcounters
• RISC-V Disassembler: Single file RISC-V Disassembler with support for RV32/RV64/RV128 IMAFDC
  • https://github.com/michaeljclark/riscv-disassembler
• RISC-V Meta – a suite of tools that operate on RISC-V ISA - https://github.com/michaeljclark/riscv-meta/
• RISC-V support for LLVM projects - http://www.lowrisc.org/llvm/status/ - https://github.com/lowRISC/riscv-llvm
• RISC-V Torture Test Generator - https://github.com/ucb-bar/riscv-torture
• Xv6 for RISC-V
  • https://github.com/mit-pdos/xv6-riscv
  • a re-implementation of Dennis Ritchie's and Ken Thompson's Unix Version 6 (v6)
  • loosely follows the structure and style of v6, but is implemented for a modern RISC-V multiprocessor using ANSI C
  • xv6-riscv-book: Text describing xv6 on RISC-V
    • https://github.com/mit-pdos/xv6-riscv-book
    • 6.S081: Operating System Engineering - https://pdos.csail.mit.edu/6.828/

Software: Binary Analysis

• MAMBO: A Low-Overhead Dynamic Binary Modification Tool for RISC architectures
  • supports Arm (both AArch32 and AArch64) and RISC-V (RV64GC)
  • https://github.com/beehive-lab/mambo
  • Evaluating the Impact of Optimizations for Dynamic Binary Modification on 64-bit RISC-V
    • 2023 IEEE International Symposium on Performance Analysis of Systems and Software (ISPASS)
    • John Alistair Kressel, Guillermo Callaghan, Cosmin Gorgovan, Mikel Luján
    • https://research.manchester.ac.uk/en/publications/evaluating-the-impact-of-optimizations-for-dynamic-binary-modific

Software: Emulation & Simulation

• Banshee: A Fast LLVM-Based RISC-V Binary Translator
  • https://github.com/pulp-platform/snitch/tree/master/sw/banshee
  • International Conference on Computer-Aided Design (ICCAD) 2021
    • Samuel Riedel, Fabian Schuiki, Paul Scheffler, Florian Zaruba, Luca Benini
    • https://pulp-platform.org/docs/Banshee_ICCAD_2021.pdf
    • https://www.research-collection.ethz.ch/handle/20.500.11850/517913
• BRISC-V: an open-source, RISC-V based, full multicore, design space exploration platform
  • https://ascslab.org/research/briscv/index.html
  • BRISC-V Explorer (RTL) - http://ascslab.org/research/briscv/explorer/explorer.html
  • BRISC-V Simulator (Assembly) - http://ascslab.org/research/briscv/simulator/simulator.html
  • The BRISC-V Platform: A Practical Teaching Approach for Computer Architecture
    • Workshop on Computer Architecture Education (WCAE) 2019
    • Rashmi Agarwal, Sahan Bandara, Alan Ehret, Mihailo Isakov, Miguel Mark, Michel A. Kinsy
    • Paper: https://ascslab.org/research/briscv/wcae/a1-agrawal.pdf
    • Slides: https://drive.google.com/file/d/1j969LvF8yN8OBsq58schBLjSh6Lfjbba/view
• Dromajo: Esperanto Technology's RISC-V Reference Model
  • RISC-V RV64GC emulator designed for RTL co-simulation
  • https://github.com/chipsalliance/dromajo
• emulsiV: A visual simulator for teaching computer architecture using the RISC-V instruction set
  • https://github.com/ESEO-Tech/emulsiV
  • https://eseo-tech.github.io/emulsiV/
• libriscv: RISC-V userspace emulator library
  • https://github.com/fwsGonzo/libriscv
  • C++17 RISC-V RV32GC userspace emulator library
• MARSS-RISCV: Micro-Architectural System Simulator for RISC-V
  • https://github.com/bucaps/marss-riscv
• mini-rv32ima: A tiny C header-only RISC-V emulator
  • https://github.com/cnlohr/mini-rv32ima
• Pydrofoil: A fast RISC-V emulator based on the RISC-V Sail model
  • https://github.com/pydrofoil/pydrofoil
  • https://docs.pydrofoil.org/en/latest/
  • Pydrofoil: A fast RISC-V emulator generated from the Sail model, using PyPy's JIT
    • 2022-12
    • https://www.youtube.com/watch?v=dUHWhUdXFJg
  • Pydrofoil: Fast CPU emulators using PyPy's JIT and Sail
    • 2022-10
    • https://www.youtube.com/watch?v=WyxKY4AU7QA
    • https://www.slideshare.net/secret/9xR1akke2qoy2N
• QtRVSim: RISC-V CPU Simulator for Education Purposes
  • https://github.com/cvut/qtrvsim
  • https://comparch.edu.cvut.cz/qtrvsim/app/
  • QtRVSim – RISC-V Simulator for Computer Architectures Classes
    • DevConf.cz Mini 2022; Jakub Dupak
    • https://www.youtube.com/watch?v=l0jfvINWgK4
• RARS: RISC-V Assembler and Runtime Simulator
  • https://github.com/TheThirdOne/rars
• Ripes: A graphical 5-stage RISC-V pipeline simulator & assembly editor
  • https://github.com/mortbopet/Ripes
• RISCVEmu Toy RISC-V emulator
  • https://github.com/jdryg/RISCVEmu
• riscvOVPsim: A Complete, Fully Functional, Configurable RISC-V Simulator
  • https://github.com/riscv/riscv-ovpsim
• rv32-sail - high-level emulator for RV32IM
  • https://github.com/thoughtpolice/rv32-sail
  • https://riscv.ls0f.pw/
• rv32emu: RISC-V RV32I[MACF] emulator with ELF support
  • https://github.com/sysprog21/rv32emu
• rv8: RISC-V simulator for x86-64 - https://rv8.io/
  • https://github.com/rv8-io/rv8
• RVirt: RISC-V hypervisor written in Rust
  • https://github.com/mit-pdos/RVirt
  • an S-mode trap-and-emulate hypervisor for RISC-V
• semu: A minimalist RISC-V emulator capable of running xv6
  • https://github.com/jserv/semu
• Spike, a RISC-V ISA Simulator
  • https://github.com/riscv/riscv-isa-sim
  • Adding a new RISC-V extension (to Spike)
    • 2023-04-14
    • https://fprox.substack.com/p/adding-a-new-risc-v-extension-to
• TinyEMU
  • https://bellard.org/tinyemu/
  • TinyEMU is a system emulator for the RISC-V architecture. Its purpose is to be small and simple while being complete.
• Venus: RISC-V instruction set simulator built for education
  • https://venus.cs61c.org/
  • https://github.com/hm-riscv/venus
  • https://github.com/ThaumicMekanism/venus
  • RISC-V Venus Simulator embedded in VS Code
    • https://github.com/hm-riscv/vscode-riscv-venus
    • https://marketplace.visualstudio.com/items?itemName=hm.riscv-venus
• WebRISC-V: a Web-Based Education-Oriented RISC-V Pipeline Simulation Environment
  • http://www.dii.unisi.it/~giorgi/WebRISC-V
  • source code: http://www.dii.unisi.it/~giorgi/WebRISC-V/download
  • Workshop on Computer Architecture Education (WCAE) 2019
  • Roberto Giorgi and Gianfranco Mariotti
  • Paper: http://www.dii.unisi.it/~giorgi/papers/Giorgi19-wcae.pdf
  • Slides: http://www.dii.unisi.it/~giorgi/giorgi19-wcae_slides.pdf

Software: Security

• Keystone: An Open Framework for Architecting Trusted Execution Environments
  • https://keystone-enclave.org
  • EuroSys 2020
    • Dayeol Lee, David Kohlbrenner, Shweta Shinde, Krste Asanovic, Dawn Song
    • https://dl.acm.org/doi/abs/10.1145/3342195.3387532
    • https://www.youtube.com/watch?v=S8MmKBCoPSg

Software: Translation

• arm2riscv: Arm AArch64 to RISC-V Transpiler
  • https://github.com/schorrm/arm2riscv
  • https://github.com/schorrm/arm2riscv/tree/master/docs
• rv32i_jit: A super simple RV32i JIT, designed for ease of understanding and modification
  • x86 backend
  • https://github.com/gamozolabs/rv32i_jit

---

Talks

2020

• Working with RISC-V: from open ISA to open Architecture to open Hardware
  • HiPEAC ACACES Summer School 2020
  • Luca Benini, Frank K. Gürkaynak
  • session 1: https://www.youtube.com/watch?v=RklEOl3xAdQ
  • session 2: https://www.youtube.com/watch?v=Ipy71G8eSWY
  • slides:
    • https://pulp-platform.org/docs/hipeac/acaces2021/01_Intro_RISC-V.pdf
    • https://pulp-platform.org/docs/hipeac/acaces2021/02_Advanced_Cores.pdf
    • https://pulp-platform.org/docs/hipeac/acaces2021/03_PULP_Concepts.pdf
    • https://pulp-platform.org/docs/hipeac/acaces2021/04_PULP_Accelerators.pdf
    • https://pulp-platform.org/docs/hipeac/acaces2021/05_PULP_Chips.pdf

2019

• The Hype Around the RISC-V Hypervisor
  • KVM Forum 2019; Alistair Francis, Anup Patel
  • https://www.youtube.com/watch?v=2MUka4lKGFU

2018

• LLVM backend development by example (RISC-V)
  • 2018 LLVM Developers’ Meeting; Alex Bradbury
  • https://www.youtube.com/watch?v=AFaIP-dF-RA
  • https://speakerdeck.com/asb/llvm-backend-development-by-example-risc-v
  • RISC-V LLVM Coding Lab at the LLVM Developers' Meeting 2018
    • https://www.lowrisc.org/llvm/devmtg18/
    • https://github.com/lowRISC/lowrisc-site/blob/master/content/llvm/devmtg18.md
  • RISC-V LLVM: a series of patches implementing a RISC-V backend for LLVM as well as initial tutorial material.
    • https://github.com/lowRISC/riscv-llvm

2017

• End-to-end formal ISA verification of RISC-V processors with riscv-formal
  • 34C3 (2017), Clifford Wolf
  • https://www.youtube.com/watch?v=VU97ffHF_IQ
  • https://media.ccc.de/v/34c3-8768-end-to-end_formal_isa_verification_of_risc-v_processors_with_riscv-formal

---

Tutorials

• Adding a new RISC-V instruction (to LLVM)
  • Extending the LLVM compiler to assemble new RISC-V instructions
  • 2023-05-05
  • https://fprox.substack.com/p/adding-a-new-risc-v-instruction-to
• "All Aboard" Blog Series
  • Part 0: Introduction: Part 0: Introduction - https://www.sifive.com/blog/2017/08/07/all-aboard-part-0-introduction/
  • Part 1: The -march, -mabi, and -mtune arguments to RISC-V Compilers - https://www.sifive.com/blog/2017/08/14/all-aboard-part-1-compiler-args/
  • Part 2: Relocations in ELF Toolchains - https://www.sifive.com/blog/2017/08/21/all-aboard-part-2-relocations/
  • Part 3: Linker Relaxation in the RISC-V Toolchain - https://www.sifive.com/blog/2017/08/28/all-aboard-part-3-linker-relaxation-in-riscv-toolchain/
  • Part 4: The RISC-V Code Models - https://www.sifive.com/blog/2017/09/11/all-aboard-part-4-risc-v-code-models/
  • Part 5: Per-march and per-mabi Library Paths on RISC-V Systems - https://www.sifive.com/blog/2017/09/18/all-aboard-part-5-risc-v-multilib/
  • Part 6: Booting a RISC-V Linux Kernel - https://www.sifive.com/blog/2017/10/09/all-aboard-part-6-booting-a-risc-v-linux-kernel/
  • Part 7: Entering and Exiting the Linux Kernel on RISC-V - https://www.sifive.com/blog/2017/10/23/all-aboard-part-7-entering-and-exiting-the-linux-kernel-on-risc-v/
  • Part 8: The RISC-V Linux Port is Upstream! - https://www.sifive.com/blog/2017/12/05/all-aboard-part-8-the-risc-v-linux-port-is-upstream/
  • Part 9: Paging and the MMU in the RISC-V Linux Kernel - https://www.sifive.com/blog/2017/12/11/all-aboard-part-9-paging-and-mmu-in-risc-v-linux-kernel/
  • Part 10: How to Contribute to the RISC-V Software Ecosystem - https://www.sifive.com/blog/2018/02/20/all-aboard-part-10-how-to-contribute-to-the-risc-v-software-ecosystem/
• Building upstream RISC-V GCC+binutils+newlib: the quick and dirty way - http://www.lowrisc.org/blog/2017/09/building-upstream-risc-v-gccbinutilsnewlib-the-quick-and-dirty-way/
• LMARV-1 (Learn Me A RISC-V, level 1)
  • https://github.com/RobertBaruch/lmarv
  • https://www.youtube.com/playlist?list=PLEeZWGE3PwbansoxKjjMKHQqS_2cm8i60
  • http://www.halfbakedmaker.org/blog/lmarv1-1
• RISC-V 101 Webinar - https://info.sifive.com/risc-v-webinar
• RISC-V ASM Tutorial Collection - Western Digital
  • https://www.youtube.com/playlist?list=PL6noQ0vZDAdh_aGvqKvxd0brXImHXMuLY
• RISC-V Assembler - Will Green
  • https://projectf.io/tags/asm/
  • Arithmetic
    • https://projectf.io/posts/riscv-arithmetic/
  • Logical
    • https://projectf.io/posts/riscv-logical/
  • Shift
    • https://projectf.io/posts/riscv-shift/
  • Load Store
    • https://projectf.io/posts/riscv-load-store/
  • Branch Set
    • https://projectf.io/posts/riscv-branch-set/
  • Jump and Function
    • https://projectf.io/posts/riscv-jump-function/
  • Multiply Divide
    • https://projectf.io/posts/riscv-multiply-divide/
• RISC-V Assembly Language Programming
  • https://github.com/johnwinans/rvalp
  • CSCI 463: Computer Architecture and Systems Organization
    • Spring 2020; John Winans
    • https://www.youtube.com/playlist?list=PL3by7evD3F50uclXhrmlwoWQicSDTy8yT
    • http://faculty.cs.niu.edu/~winans/CS463/
• RISC-V Bytes - https://danielmangum.com/categories/risc-v-bytes/
  • Cross-Platform Debugging with QEMU and GDB - https://danielmangum.com/posts/risc-v-bytes-qemu-gdb/
  • Caller and Callee Saved Registers - https://danielmangum.com/posts/risc-v-bytes-caller-callee-registers/
  • Passing on the Stack - https://danielmangum.com/posts/risc-v-bytes-passing-on-the-stack/
  • Introduction to Instruction Formats - https://danielmangum.com/posts/risc-v-bytes-intro-instruction-formats/
  • Privilege Levels - https://danielmangum.com/posts/risc-v-bytes-privilege-levels/
• RISC-V Educational Materials
  • https://riscv.org/educational-materials/
  • https://github.com/riscv/educational-materials
• RISC-V from scratch
  • 1: Introduction, toolchain setup, and hello world! - https://twilco.github.io/riscv-from-scratch/2019/03/10/riscv-from-scratch-1.html
  • 2: Hardware layouts, linker scripts, and C runtimes - https://twilco.github.io/riscv-from-scratch/2019/04/27/riscv-from-scratch-2.html
  • 3: Writing a UART driver in assembly (1 / 3) - https://twilco.github.io/riscv-from-scratch/2019/07/08/riscv-from-scratch-3.html
  • 4: Creating a function prologue for our UART driver (2 / 3) - https://twilco.github.io/riscv-from-scratch/2019/07/28/riscv-from-scratch-4.html
• RISC-V Presentation at ESC Boston 2016 - https://riscv.org/2016/04/risc-v-presentation-esc-boston/
• RISC-V QEMU
  • Part 1: Privileged ISA v1.10, HiFive1 and VirtIO - https://www.sifive.com/blog/2017/12/20/risc-v-qemu-part-1-privileged-isa-hifive1-virtio/
  • Adding RISC-V Vector Cryptography Extension support to QEMU
    • https://www.codethink.co.uk/articles/2023/vcrypto_qemu/
• RISC-V Tutorial at HPCA 2015 - https://riscv.org/2015/02/risc-v-tutorial-hpca-2015/
• Understanding Assembly Part I: RISC-V
  • https://mcyoung.xyz/2021/11/29/assembly-1/