Zhoushan Core

Open Source Chip Project by University (OSCPU)

Zhoushan is a 2-way superscalar out-of-order core, compatible with RV64I ISA.

Main developer: Li Shi (SJTU/CMU ECE)

Zhoushan in 2022

I plan to relaunch this project in 2022 summer or fall, and the future works include

1. [Microarchitecture] Redesign the cache & bus

2. [Microarchitecture] Support fast branch misprediction recovery

3. [Microarchitecture] Develop a non-blocking cache and load & store queue

4. [RISC-V ISA] Support S & U privilege modes and MMU (TLB and Sv39 page table)

5. [RISC-V ISA] Boot an OS, e.g., Linux

6. [Physical] Analyze the critical path and optimize the pipeline design

7. [Verification] Port to FPGA

If you are interested to join, feel free to contact me (lishi@andrew.cmu.edu).

Dependency

1. AM, branch: zhoushan

2. AM-Kernels, branch: master

3. NEMU, branch: master

4. ESPRESSO, branch: master

Getting Started

First, download all the dependency repositories and set the environment variables as follows.

export NOOP_HOME=<...>/Zhoushan
export NEMU_HOME=<...>/NEMU
export AM_HOME=<...>/abstract-machine
export DRAMSIM3_HOME=<...>/Zhoushan/DRAMsim3

Then, config and make NEMU and DRAMsim3, and install ESPRESSO.

To generate Verilog:

make

To build and run the binary for emulation and difftest:

make emu
./build/emu -i path/to/risc-v/binary.bin

To run functional tests:

./test.sh -c
./test.sh -r

Development Notes

Bus ID Convention

1. Bus ID is set in ZhoushanConfig.

2. Bus ID must start from 1, and should not skip any index. Bus ID must match the order of CrossbarNto1.

Git Convention

1. Branch for dev: dev/XxxYyy. Example: dev/ScalarPipeline, dev/Superscalar.

2. Only merge stable version (passing all tests) to develop branch after being permitted by Li Shi.

3. Never push or merge to master branch directly. Make a pull request.

Naming Convention

Filename & class/object/trait name & constant: CamelCase (even though it contains abbreviation, e.g., we write BhtWidth rather than BHTWidth). Example:

// SimTop.scala

class SimTop extends Module {
  ...
}

// ZhoushanConfig.scala

trait ZhoushanConfig {
  // MMIO Address Map
  val ClintAddrBase = 0x02000000
  ...
}

Function name: camelCase. Example:

def getFlag(x: UInt): Bool = x(addr_width - 1).asBool()

Wire, register, instance, io name: some_name. Example:

val this_wire = ...
val this_module = Module(new ThisModule)