1
0
mirror of https://github.com/mre/mos6502.git synced 2024-06-26 14:29:31 +00:00

Add new() methods and get main() running.

This commit is contained in:
Andrew Keeton 2014-09-27 23:58:12 -04:00
parent 2e2ba84d61
commit 0b492a9702
5 changed files with 74 additions and 42 deletions

View File

@ -25,29 +25,21 @@
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
#[deriving(PartialEq)]
#[deriving(Eq)]
#[deriving(PartialOrd)]
#[deriving(Ord)]
pub struct Address(u16);
#[deriving(PartialEq, Eq, PartialOrd, Ord)]
pub struct Address(pub u16);
impl Address {
/* TODO akeeton: Hide struct Address(u16) "constructor."
pub fn new(address_: u16) -> Address {
Address(address_)
}
*/
pub fn to_int(&self) -> u16 {
pub fn to_u16(&self) -> u16 {
match *self {
Address(address_) => address_
}
}
pub fn min() -> Address { Address(0x0100) }
pub fn max() -> Address { Address(0x01ff) }
pub fn get_page_number(&self) -> u8 {
(self.to_u16() & 0xff00 >> 8) as u8
}
pub fn is_valid(&self) -> bool {
Address::min() <= *self && *self <= Address::max()
pub fn get_offset(&self) -> u8 {
(self.to_u16() & 0x00ff) as u8
}
}

View File

@ -26,15 +26,21 @@
// POSSIBILITY OF SUCH DAMAGE.
use registers::Registers;
use address::Address;
use memory::Memory;
struct Machine {
registers: Registers,
memory: Memory
pub struct Machine {
pub registers: Registers,
pub memory: Memory
}
impl Machine {
pub fn new() -> Machine {
Machine{
registers: Registers::new(),
memory: Memory::new()
}
}
// TODO akeeton: Implement binary-coded decimal.
pub fn add_with_carry(&mut self, value: i8) {
let a: int = self.registers.accumulator as int;

View File

@ -31,5 +31,10 @@ mod address;
mod memory;
fn main() {
let machine = machine::Machine::new();
let mut machine = machine::Machine::new();
println!("A: {}", machine.registers.accumulator);
println!("add_with_carry(1)");
machine.add_with_carry(1);
println!("A: {}", machine.registers.accumulator);
}

View File

@ -27,39 +27,41 @@
use address::Address;
pub static MEMORY_ADDRESS_BEGIN: Address = Address(0x0000);
pub static MEMORY_ADDRESS_END: Address = Address(0xffff);
pub static STACK_ADDRESS_BEGIN: Address = Address(0x0100);
pub static STACK_ADDRESS_END: Address = Address(0x01ff);
// static MEMORY_SIZE: uint = MEMORY_ADDRESS_END - MEMORY_ADDRESS_BEGIN + 1;
pub struct Memory {
bytes: [u8,.. 256]
// Rust doesn't seem to like this:
// bytes: [u8, ..MEMORY_SIZE]
bytes: [u8, ..2^16]
}
impl Memory {
fn address_to_byte_offset(address: &Address) -> uint {
(address.to_int() - Address::min().to_int()) as uint
pub fn new() -> Memory {
Memory { bytes: [0, ..2^16] }
}
pub fn get_byte(&self, address: &Address) -> u8 {
if !address.is_valid()
{
fail!("Invalid address.");
}
else
{
return self.bytes[Memory::address_to_byte_offset(address)];
}
self.bytes[Memory::address_to_byte_offset(address)]
}
// Sets the byte at the given address to the given value and returns the
// previous value at the address.
pub fn set_byte(&mut self, address: &Address, value: u8) -> u8 {
if !address.is_valid()
{
fail!("Invalid address.");
}
else
{
let old_value = self.get_byte(address);
self.bytes[Memory::address_to_byte_offset(address)] = value;
let old_value = self.get_byte(address);
self.bytes[Memory::address_to_byte_offset(address)] = value;
return old_value;
}
return old_value;
}
fn address_to_byte_offset(address: &Address) -> uint {
(STACK_ADDRESS_BEGIN.to_u16() - STACK_ADDRESS_END.to_u16()) as uint
}
fn is_stack_address(address: &Address) -> bool {
STACK_ADDRESS_BEGIN <= *address && *address <= STACK_ADDRESS_END
}
}

View File

@ -25,6 +25,8 @@
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
use memory;
// Each status flag should be 0 or 1.
pub struct Status {
pub carry: u8,
@ -48,6 +50,20 @@ impl Status {
| self.overflow << 6
| self.sign << 7
}
pub fn new() -> Status {
// TODO akeeton: Revisit these defaults.
Status {
carry: 0,
zero: 0,
interrupt: 0,
decimal_mode: 0,
brk: 0,
unused: 1,
overflow: 0,
sign: 0
}
}
}
pub struct Registers {
@ -60,4 +76,15 @@ pub struct Registers {
}
impl Registers {
pub fn new() -> Registers {
// TODO akeeton: Revisit these defaults.
Registers {
accumulator: 0,
index_x: 0,
index_y: 0,
stack_pointer: memory::STACK_ADDRESS_END.get_offset(),
program_counter: 0,
status: Status::new()
}
}
}