feat(eeprom): Fix eeprom emulation timeout problem, passing the nintendo eeprom tests

Former-commit-id: 5eea390de806d03eee8c043203ae4c57d7355caa

src/core/cartridge/backup/eeprom.rs

@@ -43,7 +43,7 @@ impl Default for SpiState {
 }
 
 #[derive(Serialize, Deserialize, Clone, Debug)]
-struct EepromChip<M>
+pub struct EepromChip<M>
 where
     M: BackupMemoryInterface,
 {
@@ -57,6 +57,10 @@ where
     tx_buffer: u64,
 
     address: usize,
+
+    chip_ready: bool, // used to signal that the eeprom program was finished
+                      // In real hardware, it takes some time for the values to be programmed into the eeprom,
+                      // But we do it right away.
 }
 
 impl<M> EepromChip<M>
@@ -75,6 +79,8 @@ where
             tx_buffer: 0,
 
             address: 0,
+
+            chip_ready: false,
         }
     }
 
@@ -98,12 +104,12 @@ where
         self.tx_count = 0;
     }
 
-    fn clock_data_in(&mut self, si: u8) {
+    fn clock_data_in(&mut self, address: u32, si: u8) {
         use SpiInstruction::*;
         use SpiState::*;
 
         // Read the si signal into the rx_buffer
-        trace!("({:?}) RX bit {}", self.state, si);
+        trace!("({:?}) addr={:#x} RX bit {}", self.state, address, si);
         self.rx_buffer = (self.rx_buffer << 1) | (if si & 1 != 0 { 1 } else { 0 });
         self.rx_count += 1;
 
@@ -124,15 +130,17 @@ where
             RxAddress(insn) => {
                 if self.rx_count == 6 {
                     self.address = (self.rx_buffer as usize) * 8;
-                    debug!("recvd address = {:#x}", self.address);
+                    debug!(
+                        "{:?} mode , recvd address = {:#x} (rx_buffer={:#x})",
+                        insn, self.address, self.rx_buffer
+                    );
                     match insn {
                         Read => {
-                            self.reset_rx_buffer();
+                            next_state = Some(StopBit(Read));
-                            self.reset_tx_buffer();
-                            next_state = Some(StopBit(insn));
                         }
                         Write => {
                             next_state = Some(RxData);
+                            self.chip_ready = false;
                             self.reset_rx_buffer();
                         }
                     }
@@ -146,7 +154,7 @@ where
             RxData => {
                 if self.rx_count == 64 {
                     let mut data = self.rx_buffer;
-                    debug!("writing {:x} to memory", data);
+                    debug!("writing {:#x} to memory address {:#x}", data, self.address);
                     for i in 0..8 {
                         self.memory
                             .write(self.address + (7 - i), (data & 0xff) as u8);
@@ -157,6 +165,7 @@ where
                 }
             }
             StopBit(Write) => {
+                self.chip_ready = true;
                 self.state = RxInstruction;
                 self.reset_rx_buffer();
                 self.reset_tx_buffer();
@@ -168,7 +177,7 @@ where
         }
     }
 
-    fn clock_data_out(&mut self) -> u8 {
+    fn clock_data_out(&mut self, address: u32) -> u8 {
         use SpiState::*;
 
         let mut next_state = None;
@@ -183,22 +192,26 @@ where
                 0
             }
             TxData => {
+                let result = ((self.tx_buffer >> 63) & 1) as u8;
+                self.tx_buffer = self.tx_buffer.wrapping_shl(1);
                 self.tx_count += 1;
                 if self.tx_count == 64 {
-                    self.reset_rx_buffer();
                     self.reset_tx_buffer();
+                    self.reset_rx_buffer();
                     next_state = Some(RxInstruction);
-                    0
+                }
+                result
+            }
+            _ => {
+                if self.chip_ready {
+                    1
                 } else {
-                    let result = ((self.tx_buffer >> 63) & 1) as u8;
+                    0
-                    self.tx_buffer = self.tx_buffer << 1;
-                    result
                 }
             }
-            _ => 0,
         };
 
-        trace!("({:?}) TX bit {}", self.state, result);
+        trace!("({:?}) addr={:#x} TX bit {}", self.state, address, result);
         if let Some(next_state) = next_state {
             self.state = next_state;
         }
@@ -206,13 +219,19 @@ where
         result
     }
 
-    fn data_available(&self) -> bool {
+    pub(in crate) fn is_transmitting(&self) -> bool {
-        if let SpiState::TxData = self.state {
+        use SpiState::*;
-            true
+        match self.state {
-        } else {
+            TxData | TxDummy => true,
-            false
+            _ => false,
         }
     }
+
+    pub(in crate) fn reset(&mut self) {
+        self.state = SpiState::RxInstruction;
+        self.reset_rx_buffer();
+        self.reset_tx_buffer();
+    }
 }
 
 /// The Eeprom controller is usually mapped to the top 256 bytes of the cartridge memory
@@ -222,7 +241,7 @@ pub struct SpiController<M>
 where
     M: BackupMemoryInterface,
 {
-    chip: RefCell<EepromChip<M>>,
+    pub(in crate) chip: RefCell<EepromChip<M>>,
 }
 
 impl<M> SpiController<M>
@@ -235,53 +254,23 @@ where
         }
     }
 
-    pub fn write_half(&mut self, value: u16) {
+    pub fn write_half(&mut self, address: u32, value: u16) {
-        self.chip.borrow_mut().clock_data_in(value as u8);
+        self.chip.borrow_mut().clock_data_in(address, value as u8);
     }
 
-    pub fn read_half(&self) -> u16 {
+    pub fn read_half(&self, address: u32) -> u16 {
         let mut chip = self.chip.borrow_mut();
-        let bit = chip.clock_data_out() as u16;
+        chip.clock_data_out(address) as u16
-        if chip.data_available() {
-            bit
-        } else {
-            0
-        }
-    }
-
-    #[cfg(test)]
-    fn consume_dummy_cycles(&self) {
-        // ignore the dummy bits
-        self.read_half();
-        self.read_half();
-        self.read_half();
-        self.read_half();
-    }
-
-    #[cfg(test)]
-    fn rx_data(&self) -> [u8; 8] {
-        let mut bytes = [0; 8];
-        for byte_index in 0..8 {
-            let mut byte = 0;
-            for _ in 0..8 {
-                let bit = self.read_half() as u8;
-                byte = (byte << 1) | bit;
-            }
-            bytes[byte_index] = byte;
-        }
-        bytes
     }
 }
 
 #[cfg(test)]
 mod tests {
+    use super::super::super::EEPROM_BASE_ADDR;
     use super::super::BackupMemoryInterface;
     use super::*;
 
     use bit::BitIndex;
-    use hexdump;
-
-    use std::io::Write;
 
     #[derive(Debug)]
     struct MockMemory {
@@ -298,6 +287,29 @@ mod tests {
         }
     }
 
+    impl SpiController<MockMemory> {
+        fn consume_dummy_cycles(&self) {
+            // ignore the dummy bits
+            self.read_half(EEPROM_BASE_ADDR);
+            self.read_half(EEPROM_BASE_ADDR);
+            self.read_half(EEPROM_BASE_ADDR);
+            self.read_half(EEPROM_BASE_ADDR);
+        }
+
+        fn rx_data(&self) -> [u8; 8] {
+            let mut bytes = [0; 8];
+            for byte_index in 0..8 {
+                let mut byte = 0u8;
+                for _ in 0..8 {
+                    let bit = self.read_half(EEPROM_BASE_ADDR) as u8;
+                    byte = (byte.wrapping_shl(1)) | bit;
+                }
+                bytes[byte_index] = byte;
+            }
+            bytes
+        }
+    }
+
     fn make_mock_memory() -> MockMemory {
         let mut buffer = vec![0; 512];
         buffer[16] = 'T' as u8;
@@ -369,12 +381,12 @@ mod tests {
         // 1 bit "0" - stop bit
         let stream = make_spi_read_request(2);
         for half in stream.into_iter() {
-            spi.write_half(half);
+            spi.write_half(EEPROM_BASE_ADDR, half);
         }
 
         spi.consume_dummy_cycles();
 
-        assert!(spi.chip.borrow().data_available());
+        assert!(spi.chip.borrow().is_transmitting());
 
         let data = spi.rx_data();
 
@@ -398,7 +410,7 @@ mod tests {
         // First, lets test a read request
         let stream = make_spi_read_request(2);
         for half in stream.into_iter() {
-            spi.write_half(half);
+            spi.write_half(EEPROM_BASE_ADDR, half);
         }
         spi.consume_dummy_cycles();
         let data = spi.rx_data();
@@ -420,7 +432,7 @@ mod tests {
         bytes[4] = expected[4];
         let stream = make_spi_write_request(2, bytes);
         for half in stream.into_iter() {
-            spi.write_half(half);
+            spi.write_half(EEPROM_BASE_ADDR, half);
         }
 
         {
@@ -434,10 +446,16 @@ mod tests {
         // Also lets again read the result
         let stream = make_spi_read_request(2);
         for half in stream.into_iter() {
-            spi.write_half(half);
+            spi.write_half(EEPROM_BASE_ADDR, half);
         }
         spi.consume_dummy_cycles();
         let data = spi.rx_data();
         assert_eq!(expected, &data[0..5]);
+        {
+            let chip = spi.chip.borrow();
+            assert_eq!(SpiState::RxInstruction, chip.state);
+            assert_eq!(0, chip.rx_count);
+            assert_eq!(0, chip.tx_count);
+        }
     }
 }

src/core/cartridge/mod.rs

@@ -100,7 +100,7 @@ pub struct Cartridge {
     pub header: CartridgeHeader,
     bytes: Box<[u8]>,
     size: usize,
-    backup: BackupMedia,
+    pub(in crate) backup: BackupMedia,
 }
 
 fn load_rom(path: &Path) -> GBAResult<Vec<u8>> {
@@ -199,7 +199,7 @@ fn detect_backup_type(bytes: &[u8]) -> Option<BackupType> {
 
 use super::sysbus::consts::*;
 
-const EEPROM_BASE_ADDR: u32 = 0x0DFF_FF00;
+pub const EEPROM_BASE_ADDR: u32 = 0x0DFF_FF00;
 
 impl Bus for Cartridge {
     fn read_8(&self, addr: Addr) -> u8 {
@@ -221,9 +221,11 @@ impl Bus for Cartridge {
     }
 
     fn read_16(&self, addr: u32) -> u16 {
-        if addr & 0xff000000 == GAMEPAK_WS2_HI && (self.bytes.len() <= 16*1024*1024 || addr >= EEPROM_BASE_ADDR) {
+        if addr & 0xff000000 == GAMEPAK_WS2_HI
+            && (self.bytes.len() <= 16 * 1024 * 1024 || addr >= EEPROM_BASE_ADDR)
+        {
             if let BackupMedia::Eeprom(spi) = &self.backup {
-                return spi.read_half();
+                return spi.read_half(addr);
             }
         }
         self.default_read_16(addr)
@@ -236,14 +238,16 @@ impl Bus for Cartridge {
                 BackupMedia::Sram(memory) => memory.write((addr & 0x7FFF) as usize, value),
                 _ => {}
             },
-            _ => {}, // TODO allow the debugger to write
+            _ => {} // TODO allow the debugger to write
         };
     }
 
     fn write_16(&mut self, addr: u32, value: u16) {
-        if addr & 0xff000000 == GAMEPAK_WS2_HI && (self.bytes.len() <= 16*1024*1024 || addr >= EEPROM_BASE_ADDR) {
+        if addr & 0xff000000 == GAMEPAK_WS2_HI
+            && (self.bytes.len() <= 16 * 1024 * 1024 || addr >= EEPROM_BASE_ADDR)
+        {
             if let BackupMedia::Eeprom(spi) = &mut self.backup {
-                return spi.write_half(value);
+                return spi.write_half(addr, value);
             }
         }
         self.default_write_16(addr, value);

src/core/dma.rs

@@ -1,3 +1,4 @@
+use super::cartridge::BackupMedia;
 use super::iodev::consts::{REG_FIFO_A, REG_FIFO_B};
 use super::sysbus::SysBus;
 use super::{Bus, Interrupt, IrqBitmask};
@@ -129,6 +130,15 @@ impl DmaChannel {
     }
 
     fn xfer(&mut self, sb: &mut SysBus, irqs: &mut IrqBitmask) {
+        if self.id == 3 {
+            if let BackupMedia::Eeprom(eeprom) = &mut sb.cartridge.backup {
+                // this might be a eeprom request, so we need to reset the eeprom state machine if its dirty (due to bad behaving games, or tests roms)
+                if !eeprom.chip.borrow().is_transmitting() {
+                    eeprom.chip.borrow_mut().reset();
+                }
+            }
+        }
+
         let word_size = if self.ctrl.is_32bit() { 4 } else { 2 };
         let count = match self.internal.count {
             0 => match self.id {

src/core/sysbus.rs

@@ -115,7 +115,7 @@ pub struct SysBus {
     bios: BoxedMemory,
     onboard_work_ram: BoxedMemory,
     internal_work_ram: BoxedMemory,
-    cartridge: Cartridge,
+    pub cartridge: Cartridge,
     dummy: DummyBus,
 
     pub trace_access: bool,