RISC-V Unified Interrupt Architecture Demo

This example application demonstrates the flexibility and efficiency of Unified Interrupt Architecture based on RISC-V AIA standard. The goal is to improve the standard components by enabling advanced interrupt optimization technics such as late preemption and tail chaining.

Directory Tree

  / apps
    / hello                     hello world demo (environment check)
      - main.c                    C source file
      - linker.md                 linker script
      - Makefile                  build script
    / uclic                     uCLIC software driven late preemption and tail chaining
      - main.c                    C source file
      - linker.md                 linker script
      - Makefile                  build script
  / slib                        Supply library
    / arch                        riscv-vp (simulation) platform defines
      - crt0.S                    startup and C run-time code
      - printf.*                  compact printf()
      - semihost.*                semihost interface services
      - uclic.*                   UIA uCLIC driver  
      - utvec.S                   unified trap wrapper  

Host platform setup

The RISC-V Virtual Platform requires host computer with fresh Ubuntu 22.04 installation and working connection to the internet. Other host platforms are not yet verified/supported.

Before test applications can be executed, the following preparation steps are required on host PC:

• Mandatory packages installation

$ sudo apt-get install git autoconf automake autotools-dev curl python3 python3-pip libmpc-dev libmpfr-dev libgmp-dev gawk build-essential bison flex texinfo gperf libtool patchutils bc zlib1g-dev libexpat-dev ninja-build git cmake libglib2.0-dev libslirp-dev libncurses-dev libgoogle-perftools-dev libboost-iostreams-dev libboost-program-options-dev libboost-log-dev

• Create work folder

$ mkdir ~/Projects

• Cloning required repositories

$ cd ~/Projects
$ git clone https://github.com/riscv-collab/riscv-gnu-toolchain.git
$ git clone --branch rvvp-uclic-v0.1.0 --single-branch https://github.com/foss-for-synopsys-dwc-arc-processors/RVVP
$ git clone --branch uia-demo --single-branch https://github.com/foss-for-synopsys-dwc-arc-processors/RVDS

• Build the RISC-V GNU toolchain

$ sudo mkdir /opt/riscv-gnu-toolchain
$ sudo chmod 777 /opt/riscv-gnu-toolchain
$ git clone  https://github.com/riscv-collab/riscv-gnu-toolchain.git
$ cd ~/Projects/riscv-gnu-toolchain
$ ./configure --prefix=/opt/riscv-gnu-toolchain --with-arch=rv32i --with-abi=ilp32
$ make

• Build simulation environment

$ mkdir ~/Project/RVVP/vp/build
$ cd ~/Project/RVVP/vp/build
$ cmake ..
$ make

Now the host platform is ready to build and execute the sample applications in RISC-V Virtual Platform environment.

Custom Environment

If custom path/version is used for RISC-V toolchain, then environment variables should be defined to override the default values in demo application's Makefile:

$ export SIM_PATH=custom_path_to_riscv_vp_executable
$ export GNU_PATH=custom_path_to_riscv_gnu_toolchain
$ export LIB_PATH=custom_path_to_riscv_gcc_library

Sample application

Each example application consists of

• application source code
• simple Makefile capable of build, run and debug the application
• ReadMe file

See the ReadMe files in each application folder for details.