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gopher64-netplay/src/device/pif.rs
2025-03-16 07:35:37 +01:00

349 lines
11 KiB
Rust

mod rom;
use crate::device;
#[derive(serde::Serialize, serde::Deserialize)]
pub struct Pif {
#[serde(with = "serde_big_array::BigArray")]
pub rom: [u8; 1984],
#[serde(with = "serde_big_array::BigArray")]
pub ram: [u8; 64],
pub channels: [PifChannel; 5],
}
#[derive(Copy, Clone, serde::Serialize, serde::Deserialize)]
pub struct PifChannel {
pub tx: Option<usize>,
pub tx_buf: Option<usize>,
pub rx: Option<usize>,
pub rx_buf: Option<usize>,
#[serde(skip)]
pub process: Option<fn(&mut device::Device, usize)>,
pub pak_handler: Option<device::controller::PakHandler>,
pub change_pak: device::controller::PakType,
}
pub const PIF_RAM_SIZE: usize = 64;
const PIF_CHANNELS_COUNT: usize = 5;
const PIF_RAM_OFFSET: usize = 0x7C0;
const PIF_MASK: usize = 0xFFFF;
const CHL_LEN: usize = 0x20;
pub fn read_mem(
device: &mut device::Device,
address: u64,
_access_size: device::memory::AccessSize,
) -> u32 {
device::cop0::add_cycles(device, 3000); //based on https://github.com/rasky/n64-systembench
let mut masked_address = address as usize & PIF_MASK;
if masked_address < PIF_RAM_OFFSET {
u32::from_be_bytes(
device.pif.rom[masked_address..masked_address + 4]
.try_into()
.unwrap(),
)
} else {
masked_address -= PIF_RAM_OFFSET;
u32::from_be_bytes(
device.pif.ram[masked_address..masked_address + 4]
.try_into()
.unwrap(),
)
}
}
pub fn write_mem(device: &mut device::Device, address: u64, value: u32, mask: u32) {
let mut masked_address = address as usize & PIF_MASK;
if masked_address < PIF_RAM_OFFSET {
panic!("write to pif rom")
}
masked_address -= PIF_RAM_OFFSET;
let mut data = u32::from_be_bytes(
device.pif.ram[masked_address..masked_address + 4]
.try_into()
.unwrap(),
);
device::memory::masked_write_32(&mut data, value, mask);
device.pif.ram[masked_address..masked_address + 4].copy_from_slice(&data.to_be_bytes());
device.si.dma_dir = device::si::DmaDir::Write;
device::events::create_event(device, device::events::EVENT_TYPE_SI, 3200); //based on https://github.com/rasky/n64-systembench
device.si.regs[device::si::SI_STATUS_REG as usize] |=
device::si::SI_STATUS_DMA_BUSY | device::si::SI_STATUS_IO_BUSY
}
fn process_channel(device: &mut device::Device, channel: usize) -> usize {
/* don't process channel if it has been disabled */
if device.pif.channels[channel].tx.is_none() {
return 0;
}
/* reset Tx/Rx just in case */
device.pif.ram[device.pif.channels[channel].tx.unwrap()] &= 0x3f;
device.pif.ram[device.pif.channels[channel].rx.unwrap()] &= 0x3f;
/* set NoResponse if no device is connected */
if device.pif.channels[channel].process.is_none() {
device.pif.ram[device.pif.channels[channel].rx.unwrap()] |= 0x80;
return 0;
}
/* do device processing */
let process_handler = device.pif.channels[channel].process.unwrap();
process_handler(device, channel);
1
}
pub fn update_pif_ram(device: &mut device::Device) -> u64 {
let mut active_channels = 0;
for k in 0..PIF_CHANNELS_COUNT {
active_channels += process_channel(device, k)
}
(24000 + (active_channels * 30000)) as u64
}
fn disable_pif_channel(channel: &mut PifChannel) {
channel.tx = None;
channel.rx = None;
channel.tx_buf = None;
channel.rx_buf = None;
}
fn setup_pif_channel(device: &mut device::Device, channel: usize, buf: usize) -> usize {
let tx = device.pif.ram[buf] & 0x3f;
let rx = device.pif.ram[buf + 1] & 0x3f;
/* XXX: check out of bounds accesses */
device.pif.channels[channel].tx = Some(buf);
device.pif.channels[channel].rx = Some(buf + 1);
device.pif.channels[channel].tx_buf = Some(buf + 2);
device.pif.channels[channel].rx_buf = Some(buf + 2 + tx as usize);
(2 + tx + rx) as usize
}
fn setup_channels_format(device: &mut device::Device) {
let mut i: usize = 0;
let mut k: usize = 0;
while i < PIF_RAM_SIZE && k < PIF_CHANNELS_COUNT {
match device.pif.ram[i] {
0x00 => {
/* skip channel */
disable_pif_channel(&mut device.pif.channels[k]);
k += 1;
i += 1;
}
0xff => {
/* dummy data */
i += 1;
}
0xfe => {
/* end of channel setup - remaining channels are disabled */
while k < PIF_CHANNELS_COUNT {
disable_pif_channel(&mut device.pif.channels[k]);
k += 1;
}
}
0xfd => {
/* channel reset - send reset command and discard the results */
disable_pif_channel(&mut device.pif.channels[k]); // not sure about this
k += 1;
i += 1;
}
_ => {
/* setup channel */
/* HACK?: some games sends bogus PIF commands while accessing controller paks
* Yoshi Story, Top Gear Rally 2, Indiana Jones, ...
* When encountering such commands, we skip this bogus byte.
*/
if (i + 1 < PIF_RAM_SIZE) && (device.pif.ram[i + 1] == 0xfe) {
i += 1;
continue;
}
if (i + 2) >= PIF_RAM_SIZE {
i = PIF_RAM_SIZE;
continue;
}
i += setup_pif_channel(device, k, i);
k += 1;
}
}
}
}
pub fn process_ram(device: &mut device::Device) {
let mut clrmask = 0x00;
let command = device.pif.ram[0x3F];
if command & 0x01 != 0 {
// Configure joybus protocol
setup_channels_format(device);
clrmask |= 0x01
}
if command & 0x02 != 0 {
// Challenge / response for protection
/* disable channel processing when doing CIC challenge */
for k in 0..PIF_CHANNELS_COUNT {
disable_pif_channel(&mut device.pif.channels[k]);
}
/* CIC Challenge */
process_cic_challenge(device);
clrmask |= 0x02;
}
if command & 0x08 != 0 {
// Terminate boot process
clrmask |= 0x08;
}
if command & 0x10 != 0 {
// ROM lockout
for i in device.pif.rom.iter_mut() {
*i = 0
}
}
if command & 0x20 != 0 {
// Acquire checksum
device.pif.ram[0x3F] = 0x80
}
device.pif.ram[0x3F] &= !clrmask
}
pub fn connect_pif_channels(device: &mut device::Device) {
for i in 0..4 {
if device.netplay.is_none() {
if device.ui.config.input.controller_enabled[i] {
device.pif.channels[i].process = Some(device::controller::process);
}
} else if device.netplay.as_ref().unwrap().player_data[i].reg_id != 0 {
device.pif.channels[i].process = Some(device::controller::process);
}
}
if device.ui.config.input.emulate_vru {
device.pif.channels[3].process = Some(device::controller::vru::process);
}
device.pif.channels[4].process = Some(device::cart::process)
}
pub fn get_default_handler(device: &device::Device) -> device::controller::PakHandler {
if device.ui.game_id == "NCT" {
// Chameleon Twist does not support the mempak
device::controller::PakHandler {
read: device::controller::rumble::read,
write: device::controller::rumble::write,
pak_type: device::controller::PakType::RumblePak,
}
} else {
device::controller::PakHandler {
read: device::controller::mempak::read,
write: device::controller::mempak::write,
pak_type: device::controller::PakType::MemPak,
}
}
}
pub fn init(device: &mut device::Device) {
if device.cart.pal {
device.pif.rom = rom::PAL_PIF_ROM;
} else {
device.pif.rom = rom::NTSC_PIF_ROM;
}
device.pif.ram[0x26] = device.cart.cic_seed;
device.pif.ram[0x27] = device.cart.cic_seed;
let default_handler = get_default_handler(device);
let tpak_handler = device::controller::PakHandler {
read: device::controller::transferpak::read,
write: device::controller::transferpak::write,
pak_type: device::controller::PakType::TransferPak,
};
connect_pif_channels(device);
for i in 0..4 {
if device.netplay.is_none() {
if device.ui.config.input.controller_enabled[i] {
if device.transferpaks[i].cart.rom.is_empty() {
device.pif.channels[i].pak_handler = Some(default_handler);
} else {
device.pif.channels[i].pak_handler = Some(tpak_handler);
}
}
} else if device.netplay.as_ref().unwrap().player_data[i].reg_id != 0 {
device.pif.channels[i].pak_handler = Some(default_handler);
}
}
if device.ui.config.input.emulate_vru {
device.pif.channels[3].pak_handler = None;
}
}
fn process_cic_challenge(device: &mut device::Device) {
let mut challenge: [u8; 30] = [0; 30];
let mut response: [u8; 30] = [0; 30];
/* format the 'challenge' message into 30 nibbles for X-Scale's CIC code */
for i in 0..15 {
challenge[i * 2] = (device.pif.ram[0x30 + i] >> 4) & 0x0f;
challenge[i * 2 + 1] = device.pif.ram[0x30 + i] & 0x0f;
}
/* calculate the proper response for the given challenge (X-Scale's algorithm) */
n64_cic_nus_6105(challenge, &mut response, CHL_LEN - 2);
device.pif.ram[0x2e] = 0;
device.pif.ram[0x2f] = 0;
/* re-format the 'response' into a byte stream */
for i in 0..15 {
device.pif.ram[0x30 + i] = (response[i * 2] << 4) + response[i * 2 + 1];
}
}
fn n64_cic_nus_6105(chl: [u8; 30], rsp: &mut [u8; 30], len: usize) {
let lut0: [u8; 0x10] = [
0x4, 0x7, 0xA, 0x7, 0xE, 0x5, 0xE, 0x1, 0xC, 0xF, 0x8, 0xF, 0x6, 0x3, 0x6, 0x9,
];
let lut1: [u8; 0x10] = [
0x4, 0x1, 0xA, 0x7, 0xE, 0x5, 0xE, 0x1, 0xC, 0x9, 0x8, 0x5, 0x6, 0x3, 0xC, 0x9,
];
let mut key = 0xB;
let mut lut = lut0.as_ref();
for i in 0..len {
rsp[i] = (key + 5 * chl[i]) & 0xF;
key = lut[rsp[i] as usize];
let sgn = (rsp[i] >> 3) & 0x1;
let mut mag;
if sgn == 1 {
mag = !rsp[i]
} else {
mag = rsp[i]
}
mag &= 0x7;
let mut modd;
if mag % 3 == 1 {
modd = sgn
} else {
modd = 1 - sgn;
}
if lut == lut1 && (rsp[i] == 0x1 || rsp[i] == 0x9) {
modd = 1;
}
if lut == lut1 && (rsp[i] == 0xB || rsp[i] == 0xE) {
modd = 0;
}
if modd == 1 {
lut = &lut1;
} else {
lut = &lut0;
}
}
}