Start modeling the Lcd Display

Former-commit-id: 544f185c6f9eead870032170292b1cc8afc724bf

src/debugger/command.rs

@@ -1,6 +1,8 @@
 use crate::arm7tdmi::bus::Bus;
 use crate::arm7tdmi::{Addr, CpuState};
 use crate::disass::Disassembler;
+use crate::ioregs::consts::*;
+use crate::lcd::*;
 use crate::GBAError;
 
 use super::palette_view::create_palette_view;
@@ -20,8 +22,10 @@ pub enum DisassMode {
 #[derive(Debug, PartialEq, Clone)]
 pub enum Command {
     Info,
+    DisplayInfo,
     Step(usize),
     Continue,
+    Frame(usize),
     HexDump(Addr, usize),
     Disass(DisassMode, Addr, usize),
     AddBreakpoint(Addr),
@@ -38,6 +42,21 @@ impl Command {
         use Command::*;
         match *self {
             Info => println!("{}", debugger.gba.cpu),
+            DisplayInfo => {
+                println!("{:?}", debugger.gba.lcd);
+                println!(
+                    "DISPCNT: {:#?}",
+                    DisplayControl::from(debugger.gba.sysbus.ioregs.read_reg(REG_DISPCNT))
+                );
+                println!(
+                    "DISPSTAT: {:#?}",
+                    DisplayStatus::from(debugger.gba.sysbus.ioregs.read_reg(REG_DISPSTAT))
+                );
+                println!(
+                    "VCOUNT: {:?}",
+                    debugger.gba.sysbus.ioregs.read_reg(REG_VCOUNT)
+                );
+            }
             Step(count) => {
                 for _ in 0..count {
                     if let Some(bp) = debugger.check_breakpoint() {
@@ -95,6 +114,12 @@ impl Command {
                     _ => (),
                 };
             },
+            Frame(count) => {
+                for _ in 0..count {
+                    debugger.gba.frame();
+                    print!(".")
+                }
+            }
             HexDump(addr, nbytes) => {
                 let bytes = debugger.gba.sysbus.get_bytes(addr);
                 hexdump::hexdump(&bytes[0..nbytes]);
@@ -189,6 +214,7 @@ impl Debugger {
 
         match command.as_ref() {
             "i" | "info" => Ok(Command::Info),
+            "dispinfo" => Ok(Command::DisplayInfo),
             "s" | "step" => {
                 let count = match args.len() {
                     0 => 1,
@@ -202,6 +228,18 @@ impl Debugger {
                 Ok(Command::Step(count as usize))
             }
             "c" | "continue" => Ok(Command::Continue),
+            "f" | "frame" => {
+                let count = match args.len() {
+                    0 => 1,
+                    1 => self.val_number(&args[0])?,
+                    _ => {
+                        return Err(DebuggerError::InvalidCommandFormat(
+                            "frame [count]".to_string(),
+                        ))
+                    }
+                };
+                Ok(Command::Frame(count as usize))
+            }
             "x" | "hexdump" => {
                 let (addr, n) = match args.len() {
                     2 => {

src/gba.rs

@@ -15,11 +15,11 @@ pub struct GameBoyAdvance {
     pub sysbus: SysBus,
 
     // io devices
-    lcd: Lcd,
+    pub lcd: Lcd,
-    dma0: DmaChannel,
+    pub dma0: DmaChannel,
-    dma1: DmaChannel,
+    pub dma1: DmaChannel,
-    dma2: DmaChannel,
+    pub dma2: DmaChannel,
-    dma3: DmaChannel,
+    pub dma3: DmaChannel,
 
     post_bool_flags: bool,
 }
@@ -42,29 +42,51 @@ impl GameBoyAdvance {
         }
     }
 
+    fn run_cpu_for_n_cycles(&mut self, n: usize) {
+        let previous_cycles = self.cpu.cycles;
+        loop {
+            self.cpu.step_one(&mut self.sysbus).unwrap();
+            if n > self.cpu.cycles - previous_cycles {
+                break;
+            }
+        }
+    }
+
+    pub fn frame(&mut self) {
+        for _ in 0..Lcd::DISPLAY_HEIGHT {
+            self.run_cpu_for_n_cycles(Lcd::CYCLES_HDRAW);
+            let _irq = self.lcd.set_hblank(&mut self.sysbus);
+            self.run_cpu_for_n_cycles(Lcd::CYCLES_HBLANK);
+        }
+        let _irq = self.lcd.set_vblank(&mut self.sysbus);
+        self.run_cpu_for_n_cycles(Lcd::CYCLES_VBLANK);
+        self.lcd.render(&mut self.sysbus); // Currently not implemented
+        self.lcd.set_hdraw();
+    }
+
     pub fn step(&mut self) -> GBAResult<DecodedInstruction> {
         let previous_cycles = self.cpu.cycles;
-        let decoded = self.cpu.step_one(&mut self.sysbus)?;
+        let executed_insn = self.cpu.step_one(&mut self.sysbus)?;
 
-        // drop interrupts at the moment
+        let mut cycles = self.cpu.cycles - previous_cycles;
-        let cycles = self.cpu.cycles - previous_cycles;
-        let (dma_cycles, _) = self.dma0.step(cycles, &mut self.sysbus);
-        let cycles = cycles + dma_cycles;
 
-        let cycles = self.cpu.cycles - previous_cycles;
+        // // drop interrupts at the moment
-        let (dma_cycles, _) = self.dma1.step(cycles, &mut self.sysbus);
-        let cycles = cycles + dma_cycles;
 
-        let cycles = self.cpu.cycles - previous_cycles;
+        // let (dma_cycles, _) = self.dma0.step(cycles, &mut self.sysbus);
-        let (dma_cycles, _) = self.dma2.step(cycles, &mut self.sysbus);
+        // cycles += dma_cycles;
-        let cycles = cycles + dma_cycles;
 
-        let cycles = self.cpu.cycles - previous_cycles;
+        // let (dma_cycles, _) = self.dma1.step(cycles, &mut self.sysbus);
-        let (dma_cycles, _) = self.dma3.step(cycles, &mut self.sysbus);
+        // cycles += dma_cycles;
-        let cycles = cycles + dma_cycles;
 
-        let (lcd_cycles, _) = self.lcd.step(cycles, &mut self.sysbus);
+        // let (dma_cycles, _) = self.dma2.step(cycles, &mut self.sysbus);
+        // cycles += dma_cycles;
 
-        Ok(decoded) // return the decoded instruction for the debugger
+        // let (dma_cycles, _) = self.dma3.step(cycles, &mut self.sysbus);
+        // cycles += dma_cycles;
+
+        // let (lcd_cycles, _) = self.lcd.step(cycles, &mut self.sysbus);
+        // cycles += lcd_cycles;
+
+        Ok(executed_insn)
     }
 }

src/lcd.rs

@@ -1,4 +1,6 @@
+use super::arm7tdmi::Bus;
 use super::ioregs::consts::*;
+use super::palette::{Palette, Rgb15};
 use super::*;
 
 use crate::bit::BitIndex;
@@ -6,12 +8,12 @@ use crate::num::FromPrimitive;
 
 #[derive(Debug, Primitive)]
 enum BGMode {
-    Mode0 = 0,
+    BGMode0 = 0,
-    Mode1 = 1,
+    BGMode1 = 1,
-    Mode2 = 2,
+    BGMode2 = 2,
-    Mode3 = 3,
+    BGMode3 = 3,
-    Mode4 = 4,
+    BGMode4 = 4,
-    Mode5 = 5,
+    BGMode5 = 5,
 }
 
 #[derive(Debug)]
@@ -21,10 +23,7 @@ pub struct DisplayControl {
     hblank_interval_free: bool,
     obj_character_vram_mapping: bool, // true - 1 dimentional, false - 2 dimentional
     forced_blank: bool,
-    disp_bg0: bool,
+    disp_bg: [bool; 4],
-    disp_bg1: bool,
-    disp_bg2: bool,
-    disp_bg3: bool,
     disp_obj: bool,
     disp_window0: bool,
     disp_window1: bool,
@@ -40,10 +39,7 @@ impl From<u16> for DisplayControl {
             hblank_interval_free: v.bit(5),
             obj_character_vram_mapping: v.bit(6),
             forced_blank: v.bit(7),
-            disp_bg0: v.bit(8),
+            disp_bg: [v.bit(8), v.bit(9), v.bit(10), v.bit(11)],
-            disp_bg1: v.bit(9),
-            disp_bg2: v.bit(10),
-            disp_bg3: v.bit(11),
             disp_obj: v.bit(12),
             disp_window0: v.bit(13),
             disp_window1: v.bit(14),
@@ -61,6 +57,7 @@ pub struct DisplayStatus {
     hblank_irq_enable: bool,
     vcount_irq_enable: bool,
     vcount_setting: u8,
+    raw_value: u16,
 }
 
 impl From<u16> for DisplayStatus {
@@ -74,35 +71,210 @@ impl From<u16> for DisplayStatus {
             vcount_irq_enable: v.bit(5),
             // bits 6-7 are unused in GBA
             vcount_setting: v.bit_range(8..15) as u8,
+            raw_value: v,
         }
     }
 }
 
+#[derive(Debug)]
+pub struct BgControl {
+    bg_priority: u8,
+    character_base_block: u8,
+    moasic: bool,
+    colors_palettes: bool, // 0=16/16, 1=256/1)
+    screen_base_block: u8,
+    wraparound: bool,
+    screen_width: usize,
+    screen_height: usize,
+}
+
+impl From<u16> for BgControl {
+    fn from(v: u16) -> Self {
+        let (width, height) = match v.bit_range(14..15) {
+            0 => (256, 256),
+            1 => (512, 256),
+            2 => (256, 512),
+            3 => (512, 512),
+            _ => unreachable!(),
+        };
+        BgControl {
+            bg_priority: v.bit_range(0..1) as u8,
+            character_base_block: v.bit_range(2..3) as u8,
+            moasic: v.bit(6),
+            colors_palettes: v.bit(7), // 0=16/16, 1=256/1)
+            screen_base_block: v.bit_range(8..12) as u8,
+            wraparound: v.bit(13),
+            screen_width: width,
+            screen_height: height,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Copy, Clone)]
+pub enum LcdState {
+    HDraw = 0,
+    HBlank,
+    VBlank,
+}
+impl Default for LcdState {
+    fn default() -> LcdState {
+        LcdState::HDraw
+    }
+}
+use LcdState::*;
+
 #[derive(Debug, Default)]
 pub struct Lcd {
     cycles: usize,
+    state: LcdState,
     current_scanline: usize, // VCOUNT
 }
 
 impl Lcd {
-    const DISPLAY_WIDTH: usize = 240;
+    pub const DISPLAY_WIDTH: usize = 240;
-    const DISPLAY_HEIGHT: usize = 160;
+    pub const DISPLAY_HEIGHT: usize = 160;
+
+    pub const CYCLES_PIXEL: usize = 4;
+    pub const CYCLES_HDRAW: usize = 960;
+    pub const CYCLES_HBLANK: usize = 272;
+    pub const CYCLES_SCANLINE: usize = 1232;
+    pub const CYCLES_VDRAW: usize = 197120;
+    pub const CYCLES_VBLANK: usize = 83776;
 
     pub fn new() -> Lcd {
         Lcd {
+            state: HDraw,
             ..Default::default()
         }
     }
+
+    fn palette(&self, sysbus: &SysBus) -> Palette {
+        Palette::from(sysbus.get_bytes(0x0500_0000))
     }
 
-impl EmuIoDev for Lcd {
+    fn update_regs(&self, dispstat: DisplayStatus, sysbus: &mut SysBus) {
-    fn step(&mut self, cycles: usize, sysbus: &mut SysBus) -> (usize, Option<Interrupt>) {
+        let mut v = dispstat.raw_value;
-        self.cycles += cycles;
+        v.set_bit(0, dispstat.vblank_flag);
+        v.set_bit(1, dispstat.hblank_flag);
+        v.set_bit(2, dispstat.vcount_flag);
+        sysbus.ioregs.write_reg(REG_DISPSTAT, v);
+    }
 
-        // let mut dispcnt = DisplayControl::from(sysbus.ioregs.read_reg(REG_DISPCNT));
+    pub fn set_hblank(&mut self, sysbus: &mut SysBus) -> Option<Interrupt> {
+        let dispstat = DisplayStatus::from(sysbus.ioregs.read_reg(REG_DISPSTAT));
+        let mut v = dispstat.raw_value;
+        v.set_bit(1, true);
+        self.state = HBlank;
+        sysbus.ioregs.write_reg(REG_DISPSTAT, v);
+
+        if dispstat.hblank_irq_enable {
+            Some(Interrupt::LCD_HBlank)
+        } else {
+            None
+        }
+    }
+
+    pub fn set_vblank(&mut self, sysbus: &mut SysBus) -> Option<Interrupt> {
+        let dispstat = DisplayStatus::from(sysbus.ioregs.read_reg(REG_DISPSTAT));
+        let mut v = dispstat.raw_value;
+        v.set_bit(1, false);
+        v.set_bit(0, true);
+        self.state = HBlank;
+        sysbus.ioregs.write_reg(REG_DISPSTAT, v);
+
+        if dispstat.vblank_irq_enable {
+            Some(Interrupt::LCD_VBlank)
+        } else {
+            None
+        }
+    }
+
+    pub fn set_hdraw(&mut self) {
+        self.state = HDraw;
+    }
+
+    fn bgcnt(&self, sysbus: &SysBus, bg: u32) -> BgControl {
+        BgControl::from(sysbus.ioregs.read_reg(REG_BG0CNT + 2 * bg))
+    }
+
+    pub fn render(&mut self, sysbus: &SysBus) {
+        // let dispcnt = DisplayControl::from(sysbus.ioregs.read_reg(REG_DISPCNT));
+        // let dispstat = DisplayStatus::from(sysbus.ioregs.read_reg(REG_DISPSTAT));
+
+        // TODO - redner
+    }
+}
+
+// *TODO* Running the Lcd step by step causes a massive performance impact, so for now not treat it as an emulated IO device.
+//
+// impl EmuIoDev for Lcd {
+//     fn step(&mut self, cycles: usize, sysbus: &mut SysBus) -> (usize, Option<Interrupt>) {
+//         self.cycles += cycles;
+
+//         sysbus
+//             .ioregs
+//             .write_reg(REG_VCOUNT, self.current_scanline as u16);
 //         let mut dispstat = DisplayStatus::from(sysbus.ioregs.read_reg(REG_DISPSTAT));
 
-        // TODO
+//         dispstat.vcount_flag = dispstat.vcount_setting as usize == self.current_scanline;
-        (0, None)
+//         if dispstat.vcount_irq_enable {
-    }
+//             panic!("VCOUNT IRQ NOT IMPL");
-}
+//         }
+
+//         match self.state {
+//             HDraw => {
+//                 if self.cycles > Lcd::CYCLES_HDRAW {
+//                     self.current_scanline += 1;
+//                     self.cycles -= Lcd::CYCLES_HDRAW;
+
+//                     let (new_state, irq) = if self.current_scanline < Lcd::DISPLAY_HEIGHT {
+//                         // HBlank
+//                         dispstat.hblank_flag = true;
+//                         let irq = if dispstat.hblank_irq_enable {
+//                             Some(Interrupt::LCD_HBlank)
+//                         } else {
+//                             None
+//                         };
+//                         (HBlank, irq)
+//                     } else {
+//                         dispstat.vblank_flag = true;
+//                         let irq = if dispstat.vblank_irq_enable {
+//                             Some(Interrupt::LCD_HBlank)
+//                         } else {
+//                             None
+//                         };
+//                         (VBlank, irq)
+//                     };
+//                     self.state = new_state;
+//                     self.update_regs(dispstat, sysbus);
+//                     return (0, irq);
+//                 }
+//             }
+//             HBlank => {
+//                 if self.cycles > Lcd::CYCLES_HBLANK {
+//                     self.cycles -= Lcd::CYCLES_HBLANK;
+//                     self.state = HDraw;
+//                     dispstat.hblank_flag = false;
+//                     self.update_regs(dispstat, sysbus);
+//                     return (0, None);
+//                 }
+//             }
+//             VBlank => {
+//                 if self.cycles > Lcd::CYCLES_VBLANK {
+//                     self.cycles -= Lcd::CYCLES_VBLANK;
+//                     self.state = HDraw;
+//                     dispstat.vblank_flag = false;
+//                     self.current_scanline = 0;
+//                     self.update_regs(dispstat, sysbus);
+//                     return (0, None);
+//                 }
+//             }
+//         }
+
+//         // let mut dispcnt = DisplayControl::from(sysbus.ioregs.read_reg(REG_DISPCNT));
+//         // let mut dispstat = DisplayStatus::from(sysbus.ioregs.read_reg(REG_DISPSTAT));
+
+//         // TODO
+//         (0, None)
+//     }
+// }