MVM Tools

All mvm Tools

• mvm: A VM, just like jvm.
• masm: A Compiler that compiles the VM's Assembly language.
• msm: Assembly language for the VM.
• demasm: Disassembler for the bytecode.

MVM

A Virtual Machine capable of running bytecode, just like jvm. It is used to run programs generated by masm.

Features:

• Stack size: 942
• Turing Complete
• Own asm language

> mvm.exe -i [input.mbc]

To see a list of all Flags type:

> mvm.exe -h

MASM

The Compiler that compiles msm to .mbc (Minimalistic byte code) files.

> masm.exe [input.vsm] [output.sbc]

DEMASM

The Disassembler for the bytecode generated by the masm compiler.

> demasm.exe [input.sbc]

MSM

Assembly language for the Virtual Machine.
msm has no registers and is there for completely stack based.
Also the maximum amount of operands is only one.

NOTE: For code examples see ./examples/.

ASM Instructions:

Instruction	Arguments	Description
push	value	Pushes a value on to the stack.
dup	addr	Duplicates the value at the given stack addr.
swap	addr	Swaps the top value and the value at the given addr.
drop	NONE	Removes the top value from the stack.
plusi	stack: a, b	Adds the top two values on the stack. (for integers)
minusi	stack: a, b	Subtracts the top two values on the stack. (for integers)
multi	stack: a, b	Multiplies the top two values on the stack. (for integers)
divi	stack: a, b	Divides the top two values on the stack. (for integers)
plusf	stack: a, b	Adds the top two values on the stack. (for floats)
minusf	stack: a, b	Subtracts the top two values on the stack. (for floats)
multf	stack: a, b	Multiplies the top two values on the stack. (for floats)
divf	stack: a, b	Divides the top two values on the stack. (for floats)
equal	stack: a, b	Pushes ZERO on the stack if the top two values are not equal, else it pushes ONE.
not	stack: a	Reverses the top value on the stack. e.g. 0 to 1 and 1 to 0 (for integers, 0-1)
geeqf	a, b	Pushes ZERO on the stack if the top value on the stack is grater or equal to the second value. (for floats)
geeqi	a, b	Pushes ZERO on the stack if the top value on the stack is grater or equal to the second value. (for integers)
leeqf	a, b	Pushes ZERO on the stack if the top value on the stack is less or equal to the second value. (for floats)
leeqi	a, b	Pushes ZERO on the stack if the top value on the stack is less or equal to the second value. (for integers)
jmp	label or addr	Jumps to the the given label or addr.
jmpif	label or addr	Jumps to the the given label or addr if the top value on the stack is ZERO.
call	label or addr	Jumps to the the given label or addr and pushes the addr from the instruction after the current instruction on to the stack.
ret	stack: addr	Jumps to the the given addr (top value on the stack).
int	interruptAddr stack: args	Generates a software interrupt and calls one of the interrupt functions pointed to by the given interruptAddr, the args are parsed from the stack.
hlt	NONE	Stops the execution.

Label definition:

You can define a label by writing the name followed by a colon. You are also able to write one instruction on the same line as the label definition as shown below.

;; Fibonacci example
%include "../msmlib/stdlib.mlb"

jmp main

; Iterations:
%define I 30

; Define a label:
main:
    push 0
    push 1
    push I
; Define a label with instruction on same line:
loop: swap 2
      dup 0
      call println_u64
      dup 1
      plusi
      swap 1
      swap 2
      push 1
      minusi
      dup 0
      push 0
      equal
      not
      jmpif loop
hlt

Call definition:

In msm calls are just like label jmps with the addition that you have to kep track of the return addr that is pushed one the stack by the call instruction.

%include "../msmlib/stdlib.mlb"

jmp main

%define A 10
%define B 5

;; Function that adds to nums togeter ;;
add:
    swap 2 ; Swap the return addr to the bottom.
    plusf
    swap 1
    ret
;; ---------------------------------- ;;

main:
    push A
    push B
    call add ; Calls the functions
    ncall println_u64 ; Prints the result
    hlt

Preprocessor directives:

Instruction	Arguments	Description
define	name value	Defines a constant with name name and value value
include	path	Includes a masm lib located at the given path.

In msm all directives start with a percent sign as shown below.

include:

%include "../msmlib/stdlib.mlb"

define:

%define NUMBER 420

The value can also be a string.

%define STRING "Some string.\n"

Software Tnterrupts:

Interrupt name	Address	args	Description
print_char	0	ascii_code	Prints the given ascii_code value as char to stdout.
print_f64	1	f64_value	Prints the given f64_value value to stdout.
print_i64	2	i64_value	Prints the given i64_value value to stdout.
print_u64	3	u64_value	Prints the given u64_value value to stdout.
print_ptr	4	ptr	Prints the given ptr value to stdout.
alloc	5	size	Allocates a block of memory, returning a pointer to the beginning of the block.
free	6	ptr	Deallocates a space previously allocated by alloc, using the given 'ptr' value.
mem_dump	7	ptr size	Dumps the memory, starting from the given ptr up to ptr + size.
write	8	ptr str_size	Writes a memory string to stdout.
readline	9	NONE	Reads a line from stdin to the stack in reverse.

In msm interrupts are used as shown below. All args are parsed over the stack.

push 420
int 2 ; print_u64