Struct Cpu 

pub struct Cpu {
    pub csrs: Csrs,
    /* private fields */
}

The processor.

Fields

csrs: Csrs

Control and status registers. Public so a host can set a trap vector or inspect a cause without going through guest instructions.

Implementations

impl Cpu

pub fn new(entry: Word) -> Cpu

A processor with every register zero, starting at entry.

pub fn reg(&self, r: Reg) -> Word

Reads a register. r0 always reads zero.

pub fn set_reg(&mut self, r: Reg, value: Word)

Writes a register. Writes to r0 are discarded, which lets r0 serve as a destination for instructions run only for their side effects, such as jalr r0, r3, 0 to return without saving a link.

pub fn pc(&self) -> Word

The program counter - the tryte address of the next instruction.

pub fn set_pc(&mut self, pc: Word)

Sets the program counter.

pub fn halted(&self) -> bool

True once a halt has executed.

pub fn steps(&self) -> u64

How many instructions have executed.

pub fn privilege(&self) -> Priv

The current privilege level.

pub fn set_privilege(&mut self, level: Priv)

Sets the privilege level directly.

For a host bringing a machine up, or a test. A guest changes privilege only by taking a trap or executing tret.

pub fn reg_value(&self, n: i8) -> i64

The value in register n, numbered -13 to 13.

Panics

If n is outside the register range.

pub fn load_word<A: Addressable>( &self, virt: i64, mem: &mut A, ) -> Result<Word, Trap>

Loads a word through translation, as an instruction would.

Exposed so a host or a test can see what an address means at the machine’s current privilege without assembling a program to do it.

pub fn step<A: Addressable>(&mut self, mem: &mut A) -> Result<bool, Trap>

Executes one instruction. Returns Ok(false) once halted; further calls do nothing.

Traps

What a trap does depends on whether an operating system has claimed them. With tvec zero, which is the reset state, a trap stops the machine and is returned to the host. With tvec set, the trap is vectored to the handler and step returns normally, so a program that faults no longer takes the machine down.

pub fn run<A: Addressable>( &mut self, mem: &mut A, max_steps: u64, ) -> Result<Halted, Trap>

Runs until halt or trap, at most max_steps instructions. The budget bounds programs that do not terminate.

Trait Implementations

impl Clone for Cpu

fn clone(&self) -> Cpu

Returns a duplicate of the value.

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

Performs copy-assignment from source.