Another RISC-V ISA simulator.

This code is suitable to hard refactor at any time

This is another RISC-V ISA simulator, this is coded in SystemC + TLM-2. It supports RV32IMAC Instruction set by now.

Table of Contents

• Another RISC-V ISA simulator.
• Table of Contents
  • Description
    • Structure
  • TODO
  • Compile
  • Docker container
    • How to use Docker
  • Test
    • C code
    • FreeRTOS
  • Documentation
  • Contribute
  • License

Description

Brief description of the modules:

• CPU: Top entity that includes all other modules.
• Memory: Memory highly based on TLM-2 example with read file capability
• Registers: Implements the register file, PC register & CSR registers
• Execute: Executes ISA instructions
  • Executes C instruction extensions
  • Executes M instruction extensions
  • Executes A instruction extensions
• Instruction: Decodes instruction and acces to any instruction field
  • C_Instruction: Decodes Compressed instructions (C extension)
  • M_Instruction: Decodes Multiplication and Division instructions (M extension)
  • A_Instruction: Decodes Atomic instructions (A extension)
• Simulator: Top-level entity that builds & starts the simulation
• BusCtrl: Simple bus manager
• Trace: Simple trace peripheral
• Timer: Simple IRQ programable real-time counter peripheral

Helper classes:

• Performance: Performance indicators stores here (singleton class)
• Log: Log class to log them all (singleton class)

Current performance is about 1.500.000 instructions / sec in a Intel Core i5-5200@2.2Ghz

Structure

TODO

This is a preliminar and incomplete version.

Task to do:

• Implement all missing instructions (Execute)
• Implement CSRs (where/how?)
• Add full support to read file with memory contents (to memory.h)
  • .elf files
  • .hex files (only partial .hex support)
• Connect some TLM peripherals
  • Debug module similiar to ARM's ITM
  • Some standard UART model
  • ...
• Implement interrupts
  • implement timer (mtimecmp) & timer interrupt
  • generic IRQ comtroller
• Test, test, test & test. I'm sure there are a lot of some bugs in the code
  • riscv-test almost complete (see Test)
  • riscv-compliance WiP

• Improve structure and modules hierarchy
• Add 64 & 128 bits architecture (RV64I, RV128I)

Compile

In order to compile the project you need SystemC-2.3.2 installed in your system. Just change SYSTEMC path in Makefile.

$ make

Then, you need to modifiy your LD_LIBRARY_PATH environtment variable to add path systemc library. In my case:

$ export LD_LIBRARY_PATH=/home/marius/Work/RiscV/code/systemc-2.3.2/lib-linux64

And then you can execute the simulator:

$ ./RISCV_TLM asm/BasicLoop.hex

Arguments

-D loglevel: 3 for detailed (INFO) log, 0 to ERROR log level -f filename .hex filename to use

Docker container

There is a Docker container available with the latest release at https://hub.docker.com/r/mariusmm/riscv-tlm. This container has RISCV-TLM already build at /usr/src/riscv64/RISCV-TLM directory.

How to use Docker

$ docker pull mariusmm/riscv-tlm
$ docker run -v <localfiles>:/tmp -it mariusmm/riscv-tlm /bin/bash

# cd /usr/src/riscv64/RISCV_TLM/
# ./RISCV_TLM /tmp/<your_hex_file>

I'm using docker image zmors/riscv_gcc to have a cross-compiler, I'm using both docker images this way:

console1:
$ docker run -v /tmp:/PRJ -it zmors/riscv_gcc:1  bash

# cd /PRJ/func3
# make

console2:
$ docker run -v /tmp:/tmp -it mariusmm/riscv-tlm /bin/bash

# cd /usr/src/riscv64/RISC-V-TLM/ 
# ./RISCV-TLM /tmp/file.hex
...

or

...
console 2:
$  docker run -v /tmp/tmp -it  mariusmm/riscv-tlm /usr/src/riscv64/RISC-V-TLM/RISCV_TLM /tmp/file.hex

Performance is not affected by running the simulator inside the container

Test

See Test page for more information.

In the asm directory there are some basic assembly examples.

I "compile" one file with the follwing command:

$ cd asm
$ riscv32-unknown-elf-as  EternalLoop.asm -o EternalLoop.o
$ riscv32-unknown-elf-ld -T ../my_linker_script.ld EternalLoop.o -o EternalLoop.elf
$ riscv32-unknown-elf-objcopy -O ihex EternalLoop.elf EternalLoop.hex
$ cd ..
$ ./RISCV_SCTLM asm/EternalLoop.hex

This example needs that you hit Ctr+C to stop execution.

C code

The C directory contains simple examples in C. Each directory contains an example, to compile it just:

$ make

and then execute the .hex file like the example before.

FreeRTOS

FreeRTOS can run in this simulator!

In test/FreeRTOS/ directory there is portable files (port.c, portmacro.c portasm.S) and main file (freertos_test.c) ported to this RISC-V model.

Documentation

The code is documented using doxygen. In the doc folder there is a Doxygen.cfg file ready to be used.

Contribute

There are several ways to contribute to this project:

• Test
• Pull request are welcome (see TODO list)
• Good documentation
• RTL-Level simulation

License

Copyright (C) 2018 Màrius Montón (@mariusmonton)

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.