Building a RISC-V Hypervisor in Starina OS: From Hello World to Booting Linux

This post documents the author's journey building a lightweight RISC-V H-extension based hypervisor within the Starina operating system. Leveraging QEMU for RISC-V H-extension emulation, the author incrementally implemented guest mode entry, system call handling, a simple Hello World program, and finally, Linux kernel booting. Challenges including page table management, device tree setup, timer support, and MMIO were overcome, with detailed steps and solutions provided. The post concludes with a successful Linux boot within the Starina hypervisor.