GBC: Fix vram selection

src/cartridge.rs

@@ -84,6 +84,9 @@ impl Cartridge {
         if let &Some(ref filename) = save_file {
             let data = super::read_file(&filename);
             if let Ok(data) = data {
+                if data.len() != size {
+                    panic!("Ram size does not match");
+                }
                 data
             } else {
                 // Generate empty buffer

src/display.rs

@@ -64,6 +64,9 @@ const MONOCHROME_PALETTE: &'static [[u8; 3]; 4] = &[
 struct CgbPalette([u8; 8]);
 impl CgbPalette {
     fn get_color(&self, n: usize) -> sdl2::pixels::Color {
+        if n == 0 {
+            return sdl2::pixels::Color::RGB(255, 255, 255);
+        }
         let v = ((self.0[2 * n + 1] as u16) << 8) | (self.0[2 * n] as u16);
         let r = (v & 0b1_1111) as u8;
         let g = ((v >> 5) & 0b1_1111) as u8;
@@ -333,7 +336,7 @@ impl Display {
     pub fn write_byte(&mut self, addr: u16, val: u8) {
         match addr {
             0x8000..=0x9FFF => {
-                if self.vram_bank == 0 {
+                if (self.vram_bank & 1) == 0 {
                     self.vram0[(addr - 0x8000) as usize] = val
                 } else {
                     self.vram1[(addr - 0x8000) as usize] = val
@@ -392,7 +395,7 @@ impl Display {
     pub fn read_byte(&self, addr: u16) -> u8 {
         match addr {
             0x8000..=0x9FFF => {
-                if self.vram_bank == 0 {
+                if (self.vram_bank & 1) == 0 {
                     self.vram0[(addr - 0x8000) as usize]
                 } else {
                     self.vram1[(addr - 0x8000) as usize]
@@ -431,6 +434,8 @@ impl Display {
         let vram_offset: usize =
             background_map + ((tile_index_y as usize) * 32) + tile_index_x as usize;
             */
+        // Background attributes are only in this memory range.
+        assert!(vram_offset >= 0x1800 && vram_offset < 0x2000, format!("offset: {:04X}", vram_offset));
 
         BgMapAttributes(self.vram1[vram_offset])
     }
@@ -669,6 +674,11 @@ impl Display {
         }
     }
 
+    pub fn dump_vram(&self) {
+        std::fs::File::create("vram0.dat").unwrap().write_all(&self.vram0);
+        std::fs::File::create("vram1.dat").unwrap().write_all(&self.vram1);
+    }
+
     #[inline]
     fn renderscan(&mut self) {
         // Points to the background map offset to use.
@@ -738,13 +748,9 @@ impl Display {
                 let tile_id = self.vram0[vram_offset];
 
                 // GBC stuff
-                let bg_attribs = self.get_background_attribute(vram_offset);
                 // Get BG map attributes
-                let vram = if bg_attribs.vram_bank_number() == 0 {
-                    &*self.vram0
-                } else {
-                    &*self.vram1
-                };
+                let bg_attribs = self.get_background_attribute(vram_offset);
+                let vram = [&*self.vram0, &*self.vram1][bg_attribs.vram_bank_number()];
 
                 // TODO: Priority
                 let tile_offset_y = if bg_attribs.vertical_flip() {

src/interconnect.rs

@@ -265,14 +265,14 @@ impl Interconnect {
         // TODO: if some flag set, use bios, otherwise only use rom
         // For now, just use bios
         match addr {
-            0x0000..=0x100 => {
-                if self.disable_bootrom == 0 {
+            0x0000..=0x0FF | 0x200..=0x8FF => {
+                if self.disable_bootrom == 0 && self.bios.len() > addr as usize {
                     self.bios[addr as usize]
                 } else {
                     self.cartridge.read_byte(addr)
                 }
             }
-            0x100..=0x7FFF => self.cartridge.read_byte(addr),
+            0x100..=0x1FF | 0x900..=0x7FFF => self.cartridge.read_byte(addr),
             0x8000..=0x9FFF => self.display.read_byte(addr),
             0xA000..=0xBFFF => self.cartridge.read_byte(addr),
             0xC000..=0xCFFF => self.ram[(addr - 0xC000) as usize],
@@ -344,6 +344,9 @@ impl Interconnect {
             0xD000..=0xDFFF => {
                 self.ram[(addr - 0xD000) as usize + self.wram_bank as usize * 0x1000] = val;
             }
+            0xE000..=0xFCFF => {
+                self.ram[(addr - 0xE000) as usize] = val;
+            }
             0xFE00..=0xFE9F => self.display.write_byte(addr, val), // OAM
             0xFF00 => {
                 // Joystick select

src/mbc/mbc1.rs

@@ -94,6 +94,11 @@ impl MBC for MBC1 {
                     _ => panic!("Invalid bank mode {:02X}", val),
                 }
             }
+            0xA000..=0xBFFF => {
+                let addr = addr - 0xA000;
+                println!("Access [{:02X}] {:04X}", self.active_ram_bank(), addr);
+                self.ram[self.active_ram_bank() as usize * 0x2000 + addr as usize] = val;
+            }
             _ => panic!("MBC1: Writing {:02X} to {:04X} not supported", val, addr),
         }
     }