NEMU

NEMU(NJU Emulator) is a simple but complete full-system emulator designed for teaching purpose. Currently it supports x86, mips32, and riscv32. To build programs run above NEMU, refer to the AM project.

The main features of NEMU include

• a small monitor with a simple debugger
  • single step
  • register/memory examination
  • expression evaluation without the support of symbols
  • watch point
  • differential testing with reference design (e.g. QEMU)
  • snapshot
• CPU core with support of most common used instructions
  • x86
    • real mode is not supported
    • x87 floating point instructions are not supported
  • mips32
    • CP1 floating point instructions are not supported
  • riscv32
    • only RV32IM
• memory
• paging
  • TLB is optional (but necessary for mips32)
  • protection is not supported
• interrupt and exception
  • protection is not supported
• 5 devices
  • Args Rom, serial, timer, keyboard, VGA
  • most of them are simplified and unprogrammable
• 2 types of I/O
  • port-mapped I/O and memory-mapped I/O