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#![allow(dead_code)]
use ppu::PPU;
use mos6502::CPU;
use cartridge::MirrorType;
use controller::Controller;
use core::cell::RefCell;
use core::ptr::null_mut;
pub trait VMem {
fn read(&self, addr: u16) -> u8;
fn write(&mut self, addr: u16, data: u8);
}
pub struct CPUMemory<'a> {
sram: [u8; 2048],
ppu: *mut PPU<'a>,
cpu: *mut CPU<'a>,
mapper: &'a RefCell<&'a mut VMem>,
ctl1: Option<&'a Controller>,
ctl2: Option<&'a Controller>
}
impl<'a> CPUMemory<'a> {
pub fn new(ppu: &mut PPU<'a>,
mapper: &'a RefCell<&'a mut VMem>,
ctl1: Option<&'a Controller>,
ctl2: Option<&'a Controller>) -> Self {
CPUMemory{sram: [0; 2048],
cpu: null_mut(),
ppu: ppu,
mapper, ctl1, ctl2}
}
pub fn init(&mut self, cpu: *mut CPU<'a>) {
self.cpu = cpu;
}
}
impl<'a> VMem for CPUMemory<'a> {
fn read(&self, addr: u16) -> u8 {
if addr < 0x2000 {
self.sram[(addr & 0x07ff) as usize]
} else if addr < 0x4000 {
let ppu = unsafe {&mut *self.ppu};
match addr & 0x7 {
0x2 => ppu.read_status(),
0x4 => ppu.read_oamdata(),
0x7 => ppu.read_data(),
_ => 0
}
} else if addr < 0x4020 {
match addr {
0x4016 => if let Some(c) = self.ctl1 { c.read() } else { 0 },
0x4017 => if let Some(c) = self.ctl2 { c.read() } else { 0 },
_ => 0
}
} else if addr < 0x6000 {
0
} else {
self.mapper.borrow().read(addr)
}
}
fn write(&mut self, addr: u16, data: u8) {
let ppu = unsafe {&mut *self.ppu};
let cpu = unsafe {&mut *self.cpu};
if addr < 0x2000 {
self.sram[(addr & 0x07ff) as usize] = data;
} else if addr < 0x4000 {
match addr & 0x7 {
0x0 => {
let old = ppu.get_flag_nmi();
ppu.write_ctl(data);
if !old && ppu.try_nmi() && ppu.vblank {
cpu.trigger_delayed_nmi()
} /* toggle NMI flag can generate multiple ints */
},
0x1 => ppu.write_mask(data),
0x3 => ppu.write_oamaddr(data),
0x4 => ppu.write_oamdata(data),
0x5 => ppu.write_scroll(data),
0x6 => ppu.write_addr(data),
0x7 => ppu.write_data(data),
_ => panic!("invalid ppu reg write access at 0x{:04x}", addr)
}
} else if addr < 0x4020 {
match addr {
0x4014 => ppu.write_oamdma(data, cpu),
0x4016 => {
if let Some(c) = self.ctl1 { c.write(data) }
if let Some(c) = self.ctl2 { c.write(data) }
}
_ => ()
}
} else if addr < 0x6000 {
} else {
self.mapper.borrow_mut().write(addr, data)
}
}
}
pub struct PPUMemory<'a> {
nametable: [u8; 0x800],
palette: [u8; 0x20],
mirror_type: MirrorType,
mapper: &'a RefCell<&'a mut VMem>,
}
impl<'a> PPUMemory<'a> {
pub fn new(mapper: &'a RefCell<&'a mut VMem>,
mirror_type: MirrorType) -> Self {
PPUMemory{
nametable: [0; 0x800],
palette: [0; 0x20],
mirror_type,
mapper}
}
}
const MIRROR_IDX: [[u8; 4]; 5] = [
[0, 0, 1, 1],
[0, 1, 0, 1],
[0, 0, 0, 0],
[1, 1, 1, 1],
[0, 1, 2, 3],
];
#[inline(always)]
fn get_mirror_addr(kind: MirrorType, addr: u16) -> u16 {
let table = addr >> 10;
let offset = addr & 0x03ff;
((MIRROR_IDX[kind as usize][table as usize] as u16) << 10) + offset
}
#[inline(always)]
fn get_mirror_palette(addr: u16) -> u16 {
if addr >= 0x10 && addr & 3 == 0 {
addr - 0x10
} else { addr }
}
impl<'a> PPUMemory<'a> {
#[inline(always)]
pub fn read_nametable(&self, addr: u16) -> u8 {
self.nametable[(get_mirror_addr(self.mirror_type, addr) & 0x7ff) as usize]
}
#[inline(always)]
pub fn read_palette(&self, addr: u16) -> u8 {
self.palette[get_mirror_palette(addr) as usize]
}
#[inline(always)]
pub fn write_nametable(&mut self, addr: u16, data: u8) {
self.nametable[(get_mirror_addr(self.mirror_type, addr) & 0x7ff) as usize] = data
}
#[inline(always)]
pub fn write_palette(&mut self, addr: u16, data: u8) {
self.palette[get_mirror_palette(addr) as usize] = data
}
#[inline(always)]
pub fn read_mapper(&self, addr: u16) -> u8 {
self.mapper.borrow().read(addr)
}
#[inline(always)]
fn write_mapper(&self, addr: u16, data: u8) {
self.mapper.borrow_mut().write(addr, data);
}
}
impl<'a> VMem for PPUMemory<'a> {
fn read(&self, mut addr: u16) -> u8 {
addr &= 0x3fff;
if addr < 0x2000 {
self.read_mapper(addr)
} else if addr < 0x3f00 {
self.read_nametable((addr - 0x2000) & 0xfff)
} else if addr < 0x4000 {
self.read_palette((addr - 0x3f00) & 0x1f)
} else {
panic!("invalid ppu read access at 0x{:04x}", addr)
}
}
fn write(&mut self, mut addr: u16, data: u8) {
addr &= 0x3fff;
if addr < 0x2000 {
self.write_mapper(addr, data);
} else if addr < 0x3f00 {
self.write_nametable((addr - 0x2000) & 0xfff, data);
} else if addr < 0x4000 {
self.write_palette((addr - 0x3f00) & 0x1f, data);
} else {
panic!("invalid ppu write access at 0x{:04x}", addr)
}
}
}
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