s3k - Simple Secure Separation Kernel

s3k is a separation kernel targetting embedded RISC-V systems.

• Documentation Index
• S3K Design
• S3K API

Configuration

Set your compiler toolchain in tools.mk. By default we have the following:

CC=riscv64-unknown-elf-gcc
AR=riscv64-unknown-elf-ar
LD=riscv64-unknown-elf-ld
SIZE=riscv64-unknown-elf-size
OBJDUMP=riscv64-unknown-elf-objdump
OBJCOPY=riscv64-unknown-elf-objcopy

Build and Run

For building and running the hello project

# Build common libraries kernel and hello project
cd projects/hello
# Build the project
make
# Run the program using QEMU
make qemu

Requirements

• RISC-V GNU Toolchain
  • We recommend that you clone the repository and build the toolchains as follows:

    ./configure --prefix=/opt/riscv --enable-multilib
    sudo make
    

    This puts riscv64-unknown-elf-* tools in /opt/riscv/bin.
  • You should then add /opt/riscv/bin to the PATH variable, e.g., PATH=/opt/riscv/bin:$PATH.
  • You can make the toolchain user only by setting --prefix=$HOME/.opt/riscv and PATH=$HOME/.opt/riscv/bin:$PATH. Then you do not need to build the toolchain with sudo.
• QEMU System RISC-V - Build or install QEMU with RISC-V.
  • You should have something like qemu-system-riscv64 installed. It allows us to use our custom kernel.
  • You should not use qemu-riscv64, this only runs/simulates a Linux kernel.

Repository structure

• kernel - The kernel source code.
  • src - C and assembly files
  • inc - Header files
  • linker.ld - Linker script
  • Makefile - Kernel's makefile
  • s3k_conf.h - Default kernel configuration
• common - Libraries for the kernel
  • inc - header files
    • drivers - UART and timer driver
    • s3k - Kernel API library
    • altc - Minimal library needed by the kernel
    • plat - Platform configurations
  • src - Source files for libraries in inc
    • start - startup files for applications
  • plat/.mk - Compiler flag and more for a platform.
• projects - Example projects using the kernel
  • demonstrator - bigger example project
  • hello - Hello, world example with two processes
  • ping-ping - IPC example
  • trapped - Trap handling example
  • wcet - deprecated project (for now)
• API.md - Kernel API
• LICENSE - MIT License file
• tools.mk - Set the compiler tools here