Educational hypervisor and os for risc-v

There are 3 components here:

• Sophia OS is a tiny multi-core OS to run a program of the dining philosophers problem.
• Nowhere OS is a tiny single core OS.
• Sagevisor is a tiny hypervisor to run Sophia OS and Nowhere OS.

Getting started

Install tools for riscv64 on Ubuntu 24.04LTS

$ sh setup.sh

Build the whole code.

$ make

Run the hypervisor and OSes. Sagevisor runs in HS-mode and and the two OSes run in VS and VU modes.

$ sh qemustart.sh

                                  +-----------------------------------------------+
                                  | dining philosophers program (runs in VU-mode) |
                                  +-----------------------------------------------+
+------------------------------+  +-----------------------------------------------+
| Nowhere OS (runs in VS-mode) |  |           Sophia OS (runs in VS-mode)         |
+------------------------------+  +-----------------------------------------------+
+---------------------------------------------------------------------------------+
|               Sagevisor hypervisor (runs in HS-mode)                            |
+---------------------------------------------------------------------------------+
+---------------------------------------------------------------------------------+
|                     OpenSBI (runs in M-mode)                                    |
+---------------------------------------------------------------------------------+
+---------------------------------------------------------------------------------+
|                     riscv64 (qemu)                                              |
+---------------------------------------------------------------------------------+