core: initialize content of RAM to 0xFF

Fixes #10

Author: Rodrigodd

core/after_boot/ppu.sav

@@ -153,8 +153,8 @@ impl GameBoy {
             trace: RefCell::new(Trace::new()),
             cpu: Cpu::default(),
             cartridge,
-            wram: [0; 0x2000],
-            hram: [0; 0x7F],
+            wram: [0xFF; 0x2000],
+            hram: [0xFF; 0x7F],
             boot_rom,
             boot_rom_active: true,
             clock_count: 0,
@@ -223,8 +223,8 @@ impl GameBoy {
         }
         // TODO: Maybe I should reset the cartridge
         self.cpu = Cpu::default();
-        self.wram = [0; 0x2000];
-        self.hram = [0; 0x7F];
+        self.wram = [0xFF; 0x2000];
+        self.hram = [0xFF; 0x7F];
         self.boot_rom_active = true;
         self.clock_count = 0;
         self.timer = Timer::new().into();
@@ -257,8 +257,8 @@ impl GameBoy {
             state: cpu::CpuState::Running,
         };
 
-        self.wram = [0; 0x2000];
-        self.hram = [0; 0x7F];
+        self.wram = [0xFF; 0x2000];
+        self.hram = [0xFF; 0x7F];
         self.hram[0x7a..=0x7c].copy_from_slice(&[0x39, 0x01, 0x2e]);
 
         self.boot_rom_active = false;

core/src/gameboy.rs

@@ -537,8 +537,8 @@ crate::save_state!(Ppu, self, ctx, data {
 impl Default for Ppu {
     fn default() -> Self {
         Self {
-            vram: [0; 0x2000],
-            oam: [0; 0xA0],
+            vram: [0xFF; 0x2000],
+            oam: [0xFF; 0xA0],
             dma_started: 0x7fff_ffff_ffff_ffff,
             dma_running: false,
             dma_block_oam: false,
@@ -603,13 +603,13 @@ impl Ppu {
         *self = Self {
             #[rustfmt::skip]
             vram: {
-                let mut vram = [0; 0x2000];
+                let mut vram = [0xFF; 0x2000];
                 vram.load_state(ctx, &mut ppu_state).unwrap();
                 vram
 
             },
             oam: {
-                let mut oam = [0; 0xA0];
+                let mut oam = [0xFF; 0xA0];
                 oam.load_state(ctx, &mut ppu_state).unwrap();
                 oam
             },