feat(sram): Implement SRAM save type

Tested to work on Kirby.
Fixes #8


Former-commit-id: 90aa60b901a4ef790592c34c2350a7349939d612

src/core/backup/mod.rs

@@ -0,0 +1,118 @@
+use std::fmt;
+use std::fs::{File, OpenOptions};
+use std::io::prelude::*;
+use std::io::SeekFrom;
+use std::path::PathBuf;
+
+use serde::de::{self, Deserialize, Deserializer, SeqAccess, Visitor};
+use serde::ser::{Serialize, SerializeStruct, Serializer};
+
+use crate::util::write_bin_file;
+
+pub mod flash;
+
+pub const BACKUP_FILE_EXT: &'static str = "sav";
+
+#[derive(Debug, Primitive, Serialize, Deserialize, Clone)]
+pub enum BackupType {
+    Eeprom = 0,
+    Sram = 1,
+    Flash = 2,
+    Flash512 = 3,
+    Flash1M = 4,
+}
+
+#[derive(Debug)]
+pub struct BackupMemory {
+    size: usize,
+    path: PathBuf,
+    file: File,
+    buffer: Vec<u8>,
+}
+
+impl Clone for BackupMemory {
+    fn clone(&self) -> Self {
+        BackupMemory::new(self.size, self.path.clone())
+    }
+}
+
+impl Serialize for BackupMemory {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut state = serializer.serialize_struct("BackupMemory", 2)?;
+        state.serialize_field("size", &self.size)?;
+        state.serialize_field("path", &self.path)?;
+        state.end()
+    }
+}
+
+impl<'de> Deserialize<'de> for BackupMemory {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct BackupMemoryVisitor;
+
+        impl<'de> Visitor<'de> for BackupMemoryVisitor {
+            type Value = BackupMemory;
+
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter.write_str("struct BackupMemory")
+            }
+
+            fn visit_seq<V>(self, mut seq: V) -> Result<BackupMemory, V::Error>
+            where
+                V: SeqAccess<'de>,
+            {
+                let size = seq
+                    .next_element()?
+                    .ok_or_else(|| de::Error::invalid_length(0, &self))?;
+                let path: String = seq
+                    .next_element()?
+                    .ok_or_else(|| de::Error::invalid_length(1, &self))?;
+                Ok(BackupMemory::new(size, PathBuf::from(path)))
+            }
+        }
+
+        const FIELDS: &'static [&'static str] = &["size", "path"];
+        deserializer.deserialize_struct("BackupMemory", FIELDS, BackupMemoryVisitor)
+    }
+}
+
+impl BackupMemory {
+    pub fn new(size: usize, path: PathBuf) -> BackupMemory {
+        // TODO handle errors without unwrap
+        if !path.is_file() {
+            write_bin_file(&path, &vec![0xff; size]).unwrap();
+        };
+
+        let mut file = OpenOptions::new()
+            .read(true)
+            .write(true)
+            .open(&path)
+            .unwrap();
+
+        let mut buffer = Vec::new();
+        file.read_to_end(&mut buffer).unwrap();
+        buffer.resize(size, 0xff);
+
+        BackupMemory {
+            size,
+            path,
+            file: file,
+            buffer: buffer,
+        }
+    }
+
+    pub fn write(&mut self, offset: usize, value: u8) {
+        self.buffer[offset] = value;
+        self.file.seek(SeekFrom::Start(offset as u64)).unwrap();
+        self.file.write_all(&[value]).unwrap();
+    }
+
+    pub fn read(&self, offset: usize) -> u8 {
+        self.buffer[offset]
+    }
+}

src/core/cartridge.rs

@@ -1,16 +1,19 @@
 use std::fs::File;
 use std::io::prelude::*;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::str::from_utf8;
 
-use serde::{Deserialize, Serialize};
 use memmem::{Searcher, TwoWaySearcher};
 use num::FromPrimitive;
+use serde::{Deserialize, Serialize};
 use zip::ZipArchive;
 
 use super::super::util::read_bin_file;
 use super::{Addr, Bus, GBAResult};
 
+use super::backup::flash::*;
+use super::backup::{BackupMemory, BackupType, BACKUP_FILE_EXT};
+
 /// From GBATEK
 ///
 /// The first 192 bytes at 8000000h-80000BFh in ROM are used as cartridge header. The same header is also used for Multiboot images at 2000000h-20000BFh (plus some additional multiboot entries at 20000C0h and up).
@@ -70,13 +73,24 @@ impl CartridgeHeader {
     }
 }
 
-#[derive(Debug, Primitive, Serialize, Deserialize, Clone)]
+#[derive(Serialize, Deserialize, Clone, Debug)]
-pub enum BackupType {
+pub enum BackupMedia {
-    Eeprom = 0,
+    Sram(BackupMemory),
-    Sram = 1,
+    Flash,
-    Flash = 2,
+    Eeprom,
-    Flash512 = 3,
+    Undetected,
-    Flash1M = 4,
+}
+
+impl BackupMedia {
+    pub fn type_string(&self) -> &'static str {
+        use BackupMedia::*;
+        match self {
+            Sram(..) => "SRAM",
+            Flash => "FLASH",
+            Eeprom => "EEPROM",
+            Undetected => "Undetected",
+        }
+    }
 }
 
 #[derive(Serialize, Deserialize, Clone, Debug)]
@@ -84,6 +98,7 @@ pub struct Cartridge {
     pub header: CartridgeHeader,
     bytes: Box<[u8]>,
     size: usize,
+    backup: BackupMedia,
 }
 
 fn load_rom(path: &Path) -> GBAResult<Vec<u8>> {
@@ -117,48 +132,90 @@ fn load_rom(path: &Path) -> GBAResult<Vec<u8>> {
 impl Cartridge {
     pub fn from_path(rom_path: &Path) -> GBAResult<Cartridge> {
         let rom_bin = load_rom(rom_path)?;
-        Ok(Cartridge::from_bytes(&rom_bin))
+        Ok(Cartridge::from_bytes(
+            &rom_bin,
+            Some(rom_path.to_path_buf()),
+        ))
     }
 
-    pub fn from_bytes(bytes: &[u8]) -> Cartridge {
+    pub fn from_bytes(bytes: &[u8], rom_path: Option<PathBuf>) -> Cartridge {
-        let backup = Cartridge::detect_backup_type(&bytes);
-        println!("Backup detected: {:?}", backup);
-
         let size = bytes.len();
         let header = CartridgeHeader::parse(&bytes);
 
+        let backup = if let Some(path) = rom_path {
+            create_backup(bytes, &path)
+        } else {
+            BackupMedia::Undetected
+        };
+        println!("Backup: {}", backup.type_string());
+
         Cartridge {
             header: header,
             bytes: bytes.into(),
             size: size,
+            backup: backup,
+        }
     }
 }
 
-    fn detect_backup_type(bin: &[u8]) -> Option<BackupType> {
+fn create_backup(bytes: &[u8], rom_path: &Path) -> BackupMedia {
+    let backup_path = rom_path.with_extension(BACKUP_FILE_EXT);
+    if let Some(backup_type) = detect_backup_type(bytes) {
+        match backup_type {
+            BackupType::Flash | BackupType::Flash512 | BackupType::Flash1M => {
+                BackupMedia::Flash
+            }
+            BackupType::Sram => BackupMedia::Sram(BackupMemory::new(0x8000, backup_path)),
+            BackupType::Eeprom => BackupMedia::Eeprom,
+        }
+    } else {
+        BackupMedia::Undetected
+    }
+}
+
+fn detect_backup_type(bytes: &[u8]) -> Option<BackupType> {
     const ID_STRINGS: &'static [&'static str] =
-            &["EEPROM_V", "SRAM_V", "FLASH_V", "FLASH512_V", "FLASH1M_V"];
+        &["EEPROM", "SRAM", "FLASH_", "FLASH512_", "FLASH1M_"];
 
     for i in 0..5 {
         let search = TwoWaySearcher::new(ID_STRINGS[i].as_bytes());
-            match search.search_in(bin) {
+        match search.search_in(bytes) {
             Some(_) => return Some(BackupType::from_u8(i as u8).unwrap()),
             _ => {}
         }
     }
+    println!("Could not detect backup type");
     return None;
 }
-}
+
+use super::sysbus::{SRAM_HI, SRAM_LO};
 
 impl Bus for Cartridge {
     fn read_8(&self, addr: Addr) -> u8 {
-        if addr >= (self.size as u32) {
+        let offset = (addr & 0x01ff_ffff) as usize;
+        match addr & 0xff000000 {
+            SRAM_LO | SRAM_HI => match &self.backup {
+                BackupMedia::Sram(memory) => memory.read((addr & 0x7FFF) as usize),
+                _ => 0,
+            },
+            _ => {
+                if offset >= self.size {
                     0xDD // TODO - open bus implementation
                 } else {
-            self.bytes[addr as usize]
+                    self.bytes[offset as usize]
+                }
+            }
         }
     }
 
-    fn write_8(&mut self, addr: Addr, value: u8) {
+    fn write_8(&mut self, addr: u32, value: u8) {
-        self.bytes[addr as usize] = value;
+        let offset = (addr & 0x01ff_ffff) as usize;
+        match addr & 0xff000000 {
+            SRAM_LO | SRAM_HI => match &mut self.backup {
+                BackupMedia::Sram(memory) => memory.write((addr & 0x7FFF) as usize, value),
+                _ => {}
+            },
+            _ => self.bytes[offset] = value,
+        };
     }
 }

src/core/gba.rs

@@ -189,11 +189,10 @@ mod tests {
     use std::cell::RefCell;
     use std::rc::Rc;
 
-    use super::super::bus::Bus;
     use super::super::arm7tdmi;
+    use super::super::bus::Bus;
     use super::super::cartridge::Cartridge;
 
-
     struct DummyInterface {}
 
     impl DummyInterface {
@@ -209,7 +208,7 @@ mod tests {
     fn make_mock_gba(rom: &[u8]) -> GameBoyAdvance {
         let bios = vec![0; 0x4000];
         let cpu = arm7tdmi::Core::new();
-        let cartridge = Cartridge::from_bytes(rom);
+        let cartridge = Cartridge::from_bytes(rom, None);
         let dummy = Rc::new(RefCell::new(DummyInterface::new()));
         let mut gba = GameBoyAdvance::new(
             cpu,

src/core/mod.rs

@@ -1,4 +1,5 @@
 pub mod arm7tdmi;
+mod backup;
 pub mod cartridge;
 pub mod gpu;
 pub mod sound;

src/core/sysbus.rs

@@ -18,10 +18,14 @@ pub const IOMEM_ADDR: u32 = 0x0400_0000;
 pub const PALRAM_ADDR: u32 = 0x0500_0000;
 pub const VRAM_ADDR: u32 = 0x0600_0000;
 pub const OAM_ADDR: u32 = 0x0700_0000;
-pub const GAMEPAK_WS0_ADDR: u32 = 0x0800_0000;
+pub const GAMEPAK_WS0_LO: u32 = 0x0800_0000;
-pub const GAMEPAK_MIRROR_WS0_ADDR: u32 = 0x0900_0000;
+pub const GAMEPAK_WS0_HI: u32 = 0x0900_0000;
-pub const GAMEPAK_WS1_ADDR: u32 = 0x0A00_0000;
+pub const GAMEPAK_WS1_LO: u32 = 0x0A00_0000;
-pub const GAMEPAK_WS2_ADDR: u32 = 0x0C00_0000;
+pub const GAMEPAK_WS1_HI: u32 = 0x0B00_0000;
+pub const GAMEPAK_WS2_LO: u32 = 0x0C00_0000;
+pub const GAMEPAK_WS2_HI: u32 = 0x0D00_0000;
+pub const SRAM_LO: u32 = 0x0E00_0000;
+pub const SRAM_HI: u32 = 0x0F00_0000;
 
 #[derive(Debug, Copy, Clone)]
 pub enum MemoryAccessType {
@@ -107,21 +111,23 @@ pub struct SysBus {
     bios: BoxedMemory,
     onboard_work_ram: BoxedMemory,
     internal_work_ram: BoxedMemory,
-    gamepak: Cartridge,
+    cartridge: Cartridge,
     dummy: DummyBus,
 
     pub trace_access: bool,
 }
 
+use ansi_term::Colour;
+
 impl SysBus {
-    pub fn new(io: IoDevices, bios_rom: Vec<u8>, gamepak: Cartridge) -> SysBus {
+    pub fn new(io: IoDevices, bios_rom: Vec<u8>, cartridge: Cartridge) -> SysBus {
         SysBus {
             io: io,
 
             bios: BoxedMemory::new(bios_rom.into_boxed_slice()),
             onboard_work_ram: BoxedMemory::new(vec![0; WORK_RAM_SIZE].into_boxed_slice()),
             internal_work_ram: BoxedMemory::new(vec![0; INTERNAL_RAM_SIZE].into_boxed_slice()),
-            gamepak: gamepak,
+            cartridge: cartridge,
             dummy: DummyBus([0; 4]),
 
             trace_access: false,
@@ -129,67 +135,93 @@ impl SysBus {
     }
 
     fn map(&self, addr: Addr) -> (&dyn Bus, Addr) {
-        let ofs = addr & 0x00ff_ffff;
         match addr & 0xff000000 {
             BIOS_ADDR => {
-                if ofs >= 0x4000 {
+                if addr >= 0x4000 {
-                    (&self.dummy, ofs) // TODO return last fetched opcode
+                    (&self.dummy, addr) // TODO return last fetched opcode
                 } else {
-                    (&self.bios, ofs)
+                    (&self.bios, addr)
                 }
             }
-            EWRAM_ADDR => (&self.onboard_work_ram, ofs & 0x3_ffff),
+            EWRAM_ADDR => (&self.onboard_work_ram, addr & 0x3_ffff),
-            IWRAM_ADDR => (&self.internal_work_ram, ofs & 0x7fff),
+            IWRAM_ADDR => (&self.internal_work_ram, addr & 0x7fff),
             IOMEM_ADDR => (&self.io, {
-                if ofs & 0xffff == 0x8000 {
+                if addr & 0xffff == 0x8000 {
                     0x800
                 } else {
-                    ofs & 0x7ff
+                    addr & 0x7ff
                 }
             }),
-            PALRAM_ADDR => (&self.io.gpu.palette_ram, ofs & 0x3ff),
+            PALRAM_ADDR => (&self.io.gpu.palette_ram, addr & 0x3ff),
             VRAM_ADDR => (&self.io.gpu.vram, {
-                let mut ofs = ofs & ((VIDEO_RAM_SIZE as u32) - 1);
+                let mut ofs = addr & ((VIDEO_RAM_SIZE as u32) - 1);
                 if ofs > 0x18000 {
                     ofs -= 0x8000;
                 }
                 ofs
             }),
-            OAM_ADDR => (&self.io.gpu.oam, ofs & 0x3ff),
+            OAM_ADDR => (&self.io.gpu.oam, addr & 0x3ff),
-            GAMEPAK_WS0_ADDR | GAMEPAK_MIRROR_WS0_ADDR | GAMEPAK_WS1_ADDR | GAMEPAK_WS2_ADDR => {
+            GAMEPAK_WS0_LO | GAMEPAK_WS0_HI | GAMEPAK_WS1_LO | GAMEPAK_WS1_HI | GAMEPAK_WS2_LO => {
-                (&self.gamepak, addr & 0x01ff_ffff)
+                (&self.cartridge, addr)
+            }
+            GAMEPAK_WS2_HI => {
+                // println!(
+                //     "[{}] Possible read form EEPROM",
+                //     Colour::Yellow.bold().paint("warn")
+                // );
+                (&self.cartridge, addr)
+            }
+            SRAM_LO | SRAM_HI => (&self.cartridge, addr),
+            _ => {
+                println!(
+                    "[{}] Trying to read address {:#x}",
+                    Colour::Yellow.bold().paint("warn"),
+                    addr
+                );
+                (&self.dummy, addr)
             }
-            _ => (&self.dummy, ofs),
         }
     }
 
     /// TODO proc-macro for generating this function
     fn map_mut(&mut self, addr: Addr) -> (&mut dyn Bus, Addr) {
-        let ofs = addr & 0x00ff_ffff;
         match addr & 0xff000000 {
-            BIOS_ADDR => (&mut self.dummy, ofs),
+            BIOS_ADDR => (&mut self.dummy, addr),
-            EWRAM_ADDR => (&mut self.onboard_work_ram, ofs & 0x3_ffff),
+            EWRAM_ADDR => (&mut self.onboard_work_ram, addr & 0x3_ffff),
-            IWRAM_ADDR => (&mut self.internal_work_ram, ofs & 0x7fff),
+            IWRAM_ADDR => (&mut self.internal_work_ram, addr & 0x7fff),
             IOMEM_ADDR => (&mut self.io, {
-                if ofs & 0xffff == 0x8000 {
+                if addr & 0xffff == 0x8000 {
                     0x800
                 } else {
-                    ofs & 0x7ff
+                    addr & 0x7ff
                 }
             }),
-            PALRAM_ADDR => (&mut self.io.gpu.palette_ram, ofs & 0x3ff),
+            PALRAM_ADDR => (&mut self.io.gpu.palette_ram, addr & 0x3ff),
             VRAM_ADDR => (&mut self.io.gpu.vram, {
-                let mut ofs = ofs & ((VIDEO_RAM_SIZE as u32) - 1);
+                let mut ofs = addr & ((VIDEO_RAM_SIZE as u32) - 1);
                 if ofs > 0x18000 {
                     ofs -= 0x8000;
                 }
                 ofs
             }),
-            OAM_ADDR => (&mut self.io.gpu.oam, ofs & 0x3ff),
+            OAM_ADDR => (&mut self.io.gpu.oam, addr & 0x3ff),
-            GAMEPAK_WS0_ADDR | GAMEPAK_MIRROR_WS0_ADDR | GAMEPAK_WS1_ADDR | GAMEPAK_WS2_ADDR => {
+            GAMEPAK_WS0_LO | GAMEPAK_WS0_HI => (&mut self.dummy, addr),
-                (&mut self.gamepak, addr & 0x01ff_ffff)
+            GAMEPAK_WS2_HI => {
+                // println!(
+                //     "[{}] Possible write to EEPROM",
+                //     Colour::Yellow.bold().paint("warn")
+                // );
+                (&mut self.dummy, addr)
+            }
+            SRAM_LO | SRAM_HI => (&mut self.cartridge, addr),
+            _ => {
+                println!(
+                    "[{}] Trying to write {:#x}",
+                    Colour::Yellow.bold().paint("warn"),
+                    addr
+                );
+                (&mut self.dummy, addr)
             }
-            _ => (&mut self.dummy, ofs),
         }
     }
 
@@ -214,7 +246,7 @@ impl SysBus {
                     cycles += 1;
                 }
             }
-            GAMEPAK_WS0_ADDR | GAMEPAK_MIRROR_WS0_ADDR => match access.0 {
+            GAMEPAK_WS0_LO | GAMEPAK_WS0_HI => match access.0 {
                 MemoryAccessType::NonSeq => match access.1 {
                     MemoryAccessWidth::MemoryAccess32 => {
                         cycles += nonseq_cycles[self.io.waitcnt.ws0_first_access() as usize];
@@ -231,9 +263,40 @@ impl SysBus {
                     }
                 }
             },
-            GAMEPAK_WS1_ADDR | GAMEPAK_WS2_ADDR => {
+            GAMEPAK_WS1_LO | GAMEPAK_WS1_HI => match access.0 {
-                panic!("unimplemented - need to refactor code with a nice macro :(")
+                MemoryAccessType::NonSeq => match access.1 {
+                    MemoryAccessWidth::MemoryAccess32 => {
+                        cycles += nonseq_cycles[self.io.waitcnt.ws1_first_access() as usize];
+                        cycles += seq_cycles[self.io.waitcnt.ws1_second_access() as usize];
                     }
+                    _ => {
+                        cycles += nonseq_cycles[self.io.waitcnt.ws1_first_access() as usize];
+                    }
+                },
+                MemoryAccessType::Seq => {
+                    cycles += seq_cycles[self.io.waitcnt.ws1_second_access() as usize];
+                    if access.1 == MemoryAccessWidth::MemoryAccess32 {
+                        cycles += seq_cycles[self.io.waitcnt.ws1_second_access() as usize];
+                    }
+                }
+            },
+            GAMEPAK_WS2_LO | GAMEPAK_WS2_HI => match access.0 {
+                MemoryAccessType::NonSeq => match access.1 {
+                    MemoryAccessWidth::MemoryAccess32 => {
+                        cycles += nonseq_cycles[self.io.waitcnt.ws2_first_access() as usize];
+                        cycles += seq_cycles[self.io.waitcnt.ws2_second_access() as usize];
+                    }
+                    _ => {
+                        cycles += nonseq_cycles[self.io.waitcnt.ws2_first_access() as usize];
+                    }
+                },
+                MemoryAccessType::Seq => {
+                    cycles += seq_cycles[self.io.waitcnt.ws2_second_access() as usize];
+                    if access.1 == MemoryAccessWidth::MemoryAccess32 {
+                        cycles += seq_cycles[self.io.waitcnt.ws2_second_access() as usize];
+                    }
+                }
+            },
             _ => {}
         }
 
@@ -243,32 +306,44 @@ impl SysBus {
 
 impl Bus for SysBus {
     fn read_32(&self, addr: Addr) -> u32 {
-        let (dev, addr) = self.map(addr);
+        if addr & 3 != 0 {
-        dev.read_32(addr & 0x1ff_fffc)
+            println!("warn: Unaligned read32 at {:#X}", addr);
+        }
+        let (dev, addr) = self.map(addr & !3);
+        dev.read_32(addr)
     }
 
     fn read_16(&self, addr: Addr) -> u16 {
-        let (dev, addr) = self.map(addr);
+        if addr & 1 != 0 {
-        dev.read_16(addr & 0x1ff_fffe)
+            println!("warn: Unaligned read16 at {:#X}", addr);
+        }
+        let (dev, addr) = self.map(addr & !1);
+        dev.read_16(addr)
     }
 
     fn read_8(&self, addr: Addr) -> u8 {
         let (dev, addr) = self.map(addr);
-        dev.read_8(addr & 0x1ff_ffff)
+        dev.read_8(addr)
     }
 
     fn write_32(&mut self, addr: Addr, value: u32) {
-        let (dev, addr) = self.map_mut(addr);
+        if addr & 3 != 0 {
-        dev.write_32(addr & 0x1ff_fffc, value);
+            println!("warn: Unaligned write32 at {:#X} (value={:#X}", addr, value);
+        }
+        let (dev, addr) = self.map_mut(addr & !3);
+        dev.write_32(addr, value);
     }
 
     fn write_16(&mut self, addr: Addr, value: u16) {
-        let (dev, addr) = self.map_mut(addr);
+        if addr & 1 != 0 {
-        dev.write_16(addr & 0x1ff_fffe, value);
+            println!("warn: Unaligned write16 at {:#X} (value={:#X}", addr, value);
+        }
+        let (dev, addr) = self.map_mut(addr & !1);
+        dev.write_16(addr, value);
     }
 
     fn write_8(&mut self, addr: Addr, value: u8) {
         let (dev, addr) = self.map_mut(addr);
-        dev.write_8(addr & 0x1ff_ffff, value);
+        dev.write_8(addr, value);
     }
 }