Struct lc3::vm::VM

pub struct VM {
    pub register: [i16; 8],
    pub pc: u16,
    pub ir: u16,
    pub supervisor: bool,
    pub priority: u8,
    pub condition: Condition,
    pub mem: [u16; 65536],
}

A single LC-3 virtual machine. Each machines processes instructions in memory, handling appropriate I/O requests in device registers.

Note: memory-mapped I/O registers are not implemented as separated fields. The VM will treat device registers as normal words in the mem.

Note: Currently interrupts are not implemented.

Fields

register: [i16; 8]

General purpose registers(R0~R7)

pc: u16

Program Counter

ir: u16

Instruction Register

supervisor: bool

Supervisor mode

priority: u8

Priority Level(PL0~PL7)

condition: Condition

Condition codes

mem: [u16; 65536]

Computer memory

Methods

impl VM

pub fn new() -> VM

Returns a new, initialized LC-3 machine, with default operating system loaded.

pub fn load_u8(&mut self, program: &[u8])

Loads a program from raw u8 slice(generally, file contents).

Panics

This function panics if program slice's length is not even or less than two(invalid header).

pub fn load_file(&mut self, path: &Path) -> Result<()>

Loads a program from given path of file.

Panics

This function panics if file contents' length is not even or less than two(invalid header).

pub fn load_u16(&mut self, entry: usize, program: &[u16])

Loads a program from u16 slice from entry point given, and set pc to it. All other load_* wrappers should convert given input program into u16 slice, and pass it to this method at the last.

Panics

This function panics if program size exceeds machine memory range. (entry + program.len() >= 65536)

pub fn psr(&self) -> u16

Calculates, and returns processor state register(PSR) value.

pub fn step(&mut self)

Executes next single instruction. This function does not care about the clock enable bit.

pub fn step_n(&mut self, n: usize)

Executes next n instructions. This function does not care about the clock enable bit.

pub fn step_with_hook<F, G>(&mut self, pre_load: F, post_store: G) where
    F: FnMut(&mut Self, usize),
    G: FnMut(&mut Self, usize), 

Executes next single instruction, with given closures passed into process_instruction. This function does not care about the clock enable bit.

pub fn run(&mut self) -> usize

Executes as much as instructions, while the clock enable bit is set to 1.

Returns the number of instructions executed.

Note: This function does not take care of KBSR/DSR, so the VM will run forever if the program calls I/O subroutines.

pub fn run_n(&mut self, n: usize) -> usize

Executes next n instructions at maximum, while the clock enable bit is set to 1.

Returns the number of instructions executed.

Note: This function does not take care of KBSR/DSR, so the VM will run forever if the program calls I/O subroutines.

pub fn run_with_io<'a>(
    &'a mut self,
    input: &mut dyn Read,
    output: &mut dyn Write
) -> usize

Shorthand for run_n_with_io(0, input, output)

pub fn run_n_with_io<'a>(
    &mut self,
    n: usize,
    input: &mut dyn Read,
    output: &mut dyn Write
) -> usize

Executes next n instructions as maximum, while the clock enable bit is set to 1. If n == 0, runs until it halts.

Additionally, handles input/output with given streams before each steps.

Returns the number of instructions executed.

Trait Implementations

impl Default for VM

fn default() -> VM

Returns empty, zero-filled virtual machine

impl Clone for VM

fn clone(&self) -> VM

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.