RISC-V Port in Supervisor Mode

[Hesham Almatary]

Enable the RISC-V Port to run in RISC-V's Supervisor Mode (S-Mode).

Status:

Uninitiated.

Introduction:

RISC-V port was merged in October 2017. However, it only runs in Machine Mode (M-Mode) which only has base-and-bound protection, but not implemented in RTEMS. RISC-V has a Supervisor Mode (S-Mode), which has an MMU and paging-based protection.

Goal:

The goal is to be able to "optionally" run RISC-V port in S-Mode.

Requirements:

Knowledge of assembly, C Programming language.
Knowledge of RISC-V architecture.
Study the implementation of riscv-pk project (RTEMS will rely on it).
Debugging experience especially at low-level/system levels.

Resources:

Current RTEMS developers.
RISC-V's user-spec and priv-1.10 manuals.

Getting started as a GSoC student on this Project

If you are interested in working on this project as a GSoC project, there are a few basics you should do.

You'll need to build the simulators (hint: Spike and/or QEMU), from riscv-tools/priv-1.10.

Build the rtems*-riscv toolchain from rtems-source-builder

Build & run the BSP

Build & run the current RISC-V BSP (e.g. using the test set) and run it on Spike and/or QEMU.

To show that you're up to speed with rebuilding RTEMS, make a change. Showing the result must be part of your proposal.

The official requirement is a ​Hello World project.

References

​Hello World Project
​RISC-V Specifications (priv-1.10)
​RISC-V's Proxy Kernel
​RISC-V's 1.10 tools