RISC-V Emulator for Sophgo SG2000 SoC (Pine64 Oz64 / Milk-V Duo S)

A RISC-V emulator was developed for the Sophgo SG2000 SoC, specifically targeting Pine64 Oz64 and Milk-V Duo SBCs. The emulator underwent updates to match the SG2000 memory map, resolve auipc overflow issues in the boot code, and emulate the 16550 UART controller. Additionally, efforts were made to emulate UART output and input registers, with a focus on handling UART interrupts and data transmission. The emulator was enhanced to support 64 interrupts, crucial for proper functioning of the UART controller. By customizing the TinyEMU emulator, daily automated testing of NuttX for SG2000 became feasible. The process involved modifying the boot code to ensure correct booting addresses and transitioning between RISC-V machine and supervisor modes. Emulation of SG2000 peripherals like GPIO was planned for future implementation. The emulator's development and testing procedures were detailed, emphasizing the importance of accurately emulating hardware components for successful system operation.