UWME

UnderWhelming MIPS Emulator

You can about the project on my website!

University of Waterloo MIPS Virtual Machine Emulator

UWME is a MIPS computer emulator. Specifically, it emulates the the specification used in the University of Waterloo's Foundations of Sequential Programs course, affectionately known as "Baby compilers".

Example

$ racket main.rkt --twoints examples/collatz.mips
Enter value for register 1: 0
Enter value for register 2: 121
Running MIPS program.
MIPS program completed normally.
$01 = 0x00000000   $02 = 0x00000001   $03 = 0x0000005f   $04 = 0x00000000   
$05 = 0x00000000   $06 = 0x00000000   $07 = 0x00000000   $08 = 0x00000000   
$09 = 0x00000000   $10 = 0x00000000   $11 = 0x00000001   $12 = 0x00000002   
$13 = 0x00000003   $14 = 0x00000000   $15 = 0x00000000   $16 = 0x00000000   
$17 = 0x00000000   $18 = 0x00000000   $19 = 0x00000000   $20 = 0x00000000   
$21 = 0x00000000   $22 = 0x00000000   $23 = 0x00000000   $24 = 0x00000000   
$25 = 0x00000000   $26 = 0x00000000   $27 = 0x00000000   $28 = 0x00000000   
$29 = 0x00000000   $30 = 0x01000000   $31 = 0x8123456c

How to use it

To emulate mips.twoints:

racket main.rkt --twoints <binary>

To emulate mips.array:

racket main.rkt --array <binary>

Read more

I blogged about the project as I developed it.

1. MIPS VM part 1: Planning
2. MIPS VM part 2: Minimal Viable Product
3. MIPS VM part 3: Cleanup
4. MIPS VM part 4: Completing

Layout

• initialize.rkt takes in command-line input, and starts the program

• cycle.rkt contains the fetch-decode-execute loop

  • cpu.rkt is a map of opcode names to functions
  • alu.rkt is a map of funct names to functions

• constants.rkt contains constants common to the entire project

• word.rkt is a wrapper for a word, which exposes the relevant fields as integers

• registerfile.rkt is a wrapper for the register file

• memory.rkt is a wrapper for the memory of the program

To do

• Use closures instead of global variables
• Write unit tests for each opcode / function
• Remove TODOs from code