fix: extend rom space for minish cap/eeprom

src/arm/interpreter/arm7tdmi.rs

@@ -1,9 +1,7 @@
 use std::collections::HashMap;
 
 use crate::{
-    arm::arr_with,
-    fl,
-    mmu::{bus::Bus, game_pak::GamePak, Mcu},
+    arm::arr_with, box_arr, fl, mmu::{bus::Bus, game_pak::GamePak, Mcu}
 };
 use proc_bitfield::{bitfield, ConvRaw};
 
@@ -101,10 +99,14 @@ impl Arm7TDMI {
     pub fn new(rom: &[u8]) -> Self {
         let mut regs = [0; 16];
 
+        // Resize ROM to 32 MB always for OOB reads.
+        let mut rom_arr: Box<[u8; 0x0200_0000]> = box_arr![0; 0x0200_0000];
+        rom_arr[0..(rom.len())].copy_from_slice(rom); 
+
         // Initialize GamePak memory.
         let bus = Bus {
             game_pak: GamePak {
-                rom: rom.to_vec(),
+                rom: rom_arr,
                 sram: vec![0; 0x10000],
             },
             ..Default::default()

src/mmu/bus.rs

@@ -78,7 +78,7 @@ impl Bus {
             &mut self.iff
         );
         self.timers.tick(&mut self.iff, cycles);
-        self.dma_transfer();
+        self.dma_transfer(); // TODO: Optimize! Only call on state change.
     }
 
     fn dma_transfer(&mut self) {
@@ -171,8 +171,9 @@ impl Mcu for Bus {
             0x05 => self.palette_ram[address as usize % 0x400],
             0x06 => self.vram[address as usize % 0x0001_8000],
             0x07 => self.oam[address as usize % 0x400],
-            0x08..=0x0D => self.game_pak.rom[address as usize - 0x0800_0000],
+            0x08..=0x0D => self.game_pak.rom[address as usize & 0x00FF_FFFF],
             0x0E..=0x0F => {
+                // Flash ID workaround.
                 if address == 0x0E00_0000 {
                     0x62
                 } else if address == 0x0E00_0001 {

src/mmu/game_pak.rs

@@ -1,5 +1,12 @@
-#[derive(Default)]
+use crate::box_arr;
+
 pub struct GamePak {
-    pub rom: Vec<u8>,
+    pub rom: Box<[u8; 0x0200_0000]>,
     pub sram: Vec<u8>,
 }
+
+impl Default for GamePak {
+    fn default() -> Self {
+        Self { rom: box_arr![0; 0x0200_0000], sram: Default::default() }
+    }
+}