VNMulator

Description

VNMulator is 64-bit Von Neumann Machine emulator written in C++.

Usage

$ git init
$ git clone https://github.com/keiferchiang/VNMulator.git
$ cd VNMulator
$ ./compile
$ ./vnm [program.vnm]

Preliminary Design

Instructions

VNMulator operates on a few x86 8086 inspired instructions. The following instructions are supported:

OP	Num	Description	Notes
ADD	0x00	$r[A] := $r[A] + $r[B]
AND	0x01	$r[A] := $r[A] & $r[B]
CALL	0x02	jump to $r[A]; start call procedure
CMP	0x03	compare $r[A] and $r[B]; set flags	sets $E, $G, and/or $L flags
DEC	0x04	$r[A] := $r[A] - 1
DIV	0x05	$r[A] := $r[A] / $r[B]	unsigned integer division
HLT	0x06	halt
IDIV	0x07	$r[A] := $r[A] / $r[B]	signed integer division
IMUL	0x08	$r[A] := $r[A] * $r[B]	signed integer multiplication
IN	0x09	$r[A] := char from stdin
INC	0x0A	$r[A] := $r[A] + 1
Jcc	0x0B	jump to $r[A] if flags are set	supports JE, JNE, JGE, JG, JLE, and JL
JMP	0x0C	jump to $r[A]
LEA	0x0D	$r[A] := &($r[B])
MOD	0x0F	$r[A] := $r[A] % $r[B]
MOV	0x10	$r[A] := $r[B]
MUL	0x11	$r[A] := $r[A] * $r[B]	unsigned integer multiplication
NAND	0x12	$r[A] := ~($r[A] & $r[B])
NEG	0x13	$r[A] := -$r[A]	two's complement
NOP	0x14	no operation
NOT	0x15	$r[A] := ~$r[A]	one's complement
OR	0x16	$r[A] := $r[A] | $r[B]
OUT	0x17	stdout := $r[A]
POP	0x18	$r[A] := top of stack; pop stack
POPF	0x19	set flag(s) from stack; pop stack
PUSH	0x1A	push $r[A] on stack
PUSHF	0x1B	push flag(s) on stack
RET	0x1C	calls next instruction
SAL	0x1D	$r[A] := $r[A] << $r[B]	signed shift left
SAR	0x1E	$r[A] := $r[A] >> $r[B]	signed shift right
SHL	0x1F	$r[A] := $r[A] << $r[B]	unsigned shift left
SHR	0x20	$r[A] := $r[A] >> $r[B]	unsigned shift right
SUB	0x21	$r[A] := $r[A] - $r[B]
TEST	0x22	set $S flag if $r[A] < 0
XOR	0x23	$r[A] := $r[A] ^ $r[B]

Flags

char flags = 0b00000000
               ^^^^
               SEGL

• $S: signed flag
• $E: equality flag
• $G: greater-than flag
• $L: less-than flag

Design

For more information, see ./design/DESIGN.md

Implementation Details

Process/Module	Implementation Status	Interface	Implementation
Design	In progress	n/a	n/a
Main	Waiting	n/a	src/main.cpp
VNMulator	Waiting	include/vnmulator.h	src/vnmulator.cpp
CPU	Waiting	include/cpu.h	src/modules/cpu.cpp
Cache	Waiting	include/cache.h	src/modules/cpu/cache.cpp
L1d	Waiting	include/l1d.h	src/modules/cpu/cache/l1d.cpp
L1i	Waiting	include/l1i.h	src/modules/cpu/cache/l1i.cpp
L2	Waiting	include/l2.h	src/modules/cpu/cache/l2.cpp
L3	Waiting	include/l3.h	src/modules/cpu/cache/l3.cpp
Core	Waiting	include/core.h	src/modules/cpu/core.cpp
ALU	Waiting	include/alu.h	src/modules/cpu/core/alu.cpp
CU	Waiting	include/cu.h	src/modules/cpu/core/cu.cpp
Registers	Waiting	include/registers.h	src/modules/cpu/core/registers.cpp
Memory	Waiting	include/memory.h	src/modules/memory.cpp
RAM	Waiting	include/ram.h	src/modules/memory/ram.cpp
Segment	Waiting	include/segment.h	src/modules/memory/ram/segment.cpp
ROM	Waiting	n/a	src/modules/memory/ROM
I/O	Waiting	include/io.h	src/modules/io.cpp
Data Compressor	Waiting	include/compressor.h	src/modules/compressor.cpp
Storage	Waiting	n/a	src/modules/storage

Notes

• VNMulator currently does not support IEEE floating-point representations
• RAM module design supports concurrency

TODO

• OS
• Config CLI
• IEEE floating-point arithmetic
• Assembler