core: Implement bios read protection when CPU is not executing from bios.
Fixes #109 Fixes #106 Fixes MegaMan email menu freezing and probably some more games Former-commit-id: ed37520f2bc732b07334261dfe3d23cccf3fc04c Former-commit-id: d7f206b0f405ffe09a3b36d90268f1d683a64cea
This commit is contained in:
Michel Heily
parent
1ca261e5c7
commit
b003dc950f
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@ -4,7 +4,7 @@ pub use super::exception::Exception;
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use super::{arm::ArmCond, psr::RegPSR, Addr, CpuMode, CpuState};
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use crate::util::Shared;
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use crate::util::{Shared, WeakPointer};
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use super::memory::{MemoryAccess, MemoryInterface};
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use MemoryAccess::*;
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@ -148,6 +148,10 @@ impl<I: MemoryInterface> Core<I> {
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}
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}
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pub fn weak_ptr(&mut self) -> WeakPointer<Core<I>> {
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WeakPointer::new(self as *mut Core<I>)
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}
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pub fn from_saved_state(bus: Shared<I>, state: SavedCpuState) -> Core<I> {
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Core {
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bus,
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77
core/src/bios.rs
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77
core/src/bios.rs
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@ -0,0 +1,77 @@
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use super::arm7tdmi;
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use super::bus::{Addr, Bus, DebugRead};
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use super::util::WeakPointer;
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use super::SysBus;
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/// Struct representing the sytem ROM
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#[derive(Clone)]
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pub struct Bios {
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/// Underlying memory
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rom: Box<[u8]>,
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/// Last read value
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last_opcode: u32,
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/// Arm pointer - used only to read the PC register
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arm_core: WeakPointer<arm7tdmi::Core<SysBus>>,
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}
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impl Bios {
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pub fn new(bios_rom: Box<[u8]>) -> Bios {
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Bios {
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rom: bios_rom,
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last_opcode: 0xe129f000, // the opcode at [00DCh+8]
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arm_core: WeakPointer::default(),
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}
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}
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pub(super) fn connect_arm_core(&mut self, arm_ptr: WeakPointer<arm7tdmi::Core<SysBus>>) {
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self.arm_core = arm_ptr;
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}
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#[inline]
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fn read_allowed(&self) -> bool {
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self.arm_core.pc < 0x4000
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}
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}
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/// Impl of Bus trait for Bios
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impl Bus for Bios {
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#[inline]
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fn read_32(&mut self, addr: Addr) -> u32 {
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if self.read_allowed() {
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let value = self.rom.read_32(addr);
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// 32-bit read from bios is most probably an opcode fetch
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self.last_opcode = value;
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value
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} else {
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self.last_opcode
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}
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}
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#[inline]
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fn read_16(&mut self, addr: Addr) -> u16 {
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if self.read_allowed() {
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self.rom.read_16(addr) as u16
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} else {
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(self.last_opcode >> ((addr & 2) << 3)) as u16
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}
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}
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#[inline]
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fn read_8(&mut self, addr: Addr) -> u8 {
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if self.read_allowed() {
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self.rom.read_8(addr)
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} else {
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(self.last_opcode >> ((addr & 3) << 3)) as u8
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}
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}
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#[inline]
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fn write_8(&mut self, _addr: Addr, _value: u8) {
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// The bios is RO
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}
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}
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impl DebugRead for Bios {
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fn debug_read_8(&mut self, addr: Addr) -> u8 {
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self.rom[addr as usize]
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}
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}
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@ -113,9 +113,9 @@ impl Debugger {
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GpioInfo => println!("GPIO: {:#?}", self.gba.sysbus.cartridge.get_gpio()),
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Step(count) => {
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for _ in 0..count {
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self.gba.cpu.step();
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self.gba.step_debugger();
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while self.gba.cpu.last_executed.is_none() {
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self.gba.cpu.step();
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self.gba.step_debugger();
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}
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if let Some(last_executed) = &self.gba.cpu.last_executed {
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let pc = last_executed.get_pc();
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@ -113,7 +113,7 @@ impl GameBoyAdvance {
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interrupt_flags: interrupt_flags,
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};
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gba.sysbus.created();
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gba.sysbus.init(gba.cpu.weak_ptr());
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gba
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}
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@ -136,7 +136,7 @@ impl GameBoyAdvance {
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io_devs.connect_irq(interrupts.clone());
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io_devs.gpu.set_scheduler(scheduler.clone());
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io_devs.sound.set_scheduler(scheduler.clone());
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let sysbus = Shared::new(SysBus::new_with_memories(
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let mut sysbus = Shared::new(SysBus::new_with_memories(
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scheduler.clone(),
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io_devs.clone(),
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cartridge,
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@ -144,11 +144,13 @@ impl GameBoyAdvance {
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decoded.ewram,
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decoded.iwram,
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));
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let arm7tdmi = Box::new(arm7tdmi::Core::from_saved_state(
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let mut arm7tdmi = Box::new(arm7tdmi::Core::from_saved_state(
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sysbus.clone(),
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decoded.cpu_state,
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));
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sysbus.init(arm7tdmi.weak_ptr());
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Ok(GameBoyAdvance {
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cpu: arm7tdmi,
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sysbus: sysbus,
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@ -197,7 +199,7 @@ impl GameBoyAdvance {
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self.sysbus.set_scheduler(self.scheduler.clone());
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self.sysbus.set_io_devices(self.io_devs.clone());
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self.sysbus.cartridge.update_from(decoded.cartridge);
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self.sysbus.created();
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self.sysbus.init(self.cpu.weak_ptr());
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Ok(())
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}
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@ -354,14 +356,13 @@ impl GameBoyAdvance {
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self.dma_step();
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// Run the CPU
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let _cycles = self.scheduler.measure_cycles(|| {
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self.cpu_step();
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});
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let breakpoint = self.check_breakpoint();
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let mut _running = true;
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while let Some((event, cycles_late)) = self.scheduler.pop_pending_event() {
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self.handle_event(event, cycles_late, &mut running);
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self.handle_event(event, cycles_late, &mut _running);
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}
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breakpoint
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@ -36,6 +36,7 @@ use std::fmt;
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#[macro_use]
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pub mod util;
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pub mod arm7tdmi;
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mod bios;
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pub mod cartridge;
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pub mod disass;
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pub mod gpu;
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@ -1,6 +1,8 @@
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use serde::{Deserialize, Serialize};
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use super::arm7tdmi;
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use super::arm7tdmi::memory::*;
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use super::bios::Bios;
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use super::bus::*;
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use super::cartridge::Cartridge;
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use super::dma::DmaNotifer;
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@ -142,8 +144,9 @@ impl CycleLookupTables {
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pub struct SysBus {
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pub io: Shared<IoDevices>,
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scheduler: Shared<Scheduler>,
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arm_core: WeakPointer<arm7tdmi::Core<SysBus>>,
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bios: BoxedMemory,
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bios: Bios,
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ewram: Box<[u8]>,
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iwram: Box<[u8]>,
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pub cartridge: Cartridge,
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@ -171,9 +174,10 @@ impl SysBus {
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SysBus {
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io,
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scheduler,
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arm_core: WeakPointer::default(),
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cartridge,
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bios: bios_rom,
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bios: Bios::new(bios_rom),
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ewram,
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iwram,
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cycle_luts: luts,
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@ -217,7 +221,9 @@ impl SysBus {
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}
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/// must be called whenever this object is instanciated
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pub fn created(&mut self) {
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pub fn init(&mut self, arm_core: WeakPointer<arm7tdmi::Core<SysBus>>) {
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self.arm_core = arm_core.clone();
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self.bios.connect_arm_core(arm_core.clone());
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let ptr = SysBusPtr::new(self as *mut SysBus);
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// HACK
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self.io.set_sysbus_ptr(ptr.clone());
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@ -261,7 +267,13 @@ impl Bus for SysBus {
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#[inline]
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fn read_32(&mut self, addr: Addr) -> u32 {
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match addr & 0xff000000 {
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BIOS_ADDR => self.bios.read_32(addr),
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BIOS_ADDR => {
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if addr <= 0x3ffc {
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self.bios.read_32(addr)
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} else {
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0 // TODO open-bus
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}
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}
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EWRAM_ADDR => self.ewram.read_32(addr & 0x3_fffc),
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IWRAM_ADDR => self.iwram.read_32(addr & 0x7ffc),
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IOMEM_ADDR => {
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@ -288,7 +300,13 @@ impl Bus for SysBus {
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#[inline]
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fn read_16(&mut self, addr: Addr) -> u16 {
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match addr & 0xff000000 {
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BIOS_ADDR => self.bios.read_16(addr),
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BIOS_ADDR => {
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if addr <= 0x3ffe {
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self.bios.read_16(addr)
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} else {
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0 // TODO open-bus
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}
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}
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EWRAM_ADDR => self.ewram.read_16(addr & 0x3_fffe),
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IWRAM_ADDR => self.iwram.read_16(addr & 0x7ffe),
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IOMEM_ADDR => {
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@ -315,7 +333,13 @@ impl Bus for SysBus {
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#[inline]
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fn read_8(&mut self, addr: Addr) -> u8 {
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match addr & 0xff000000 {
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BIOS_ADDR => self.bios.read_8(addr),
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BIOS_ADDR => {
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if addr <= 0x3fff {
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self.bios.read_8(addr)
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} else {
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0 // TODO open-bus
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}
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}
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EWRAM_ADDR => self.ewram.read_8(addr & 0x3_ffff),
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IWRAM_ADDR => self.iwram.read_8(addr & 0x7fff),
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IOMEM_ADDR => {
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