initial commit

tridoraemu/tridoraemu.go

@@ -0,0 +1,159 @@
+// Copyright 2021-2024 Sebastian Lederer. See the file LICENSE.md for details
+package main
+
+import (
+	"fmt"
+	"log"
+	"errors"
+	"flag"
+	"time"
+	"github.com/hajimehoshi/ebiten/v2"
+	// "github.com/hajimehoshi/ebiten/v2/ebitenutil"
+	// "image/color"
+)
+
+const IdleTicks = 1000
+
+var consoleChan chan byte
+var cpu CPU
+var mem Mem
+var uart UART
+var framebuffer Framebuffer
+var sdspi SDSPI
+var irqc IRQC
+
+var Terminated = errors.New("terminated")
+
+var idleCounter int = IdleTicks
+
+func idle(canGoIdle bool) {
+	if canGoIdle {
+		if idleCounter > 0 { idleCounter -= 1 }
+	} else {
+		if idleCounter != IdleTicks { idleCounter = IdleTicks }
+	}
+}
+
+type Game struct{
+		x,y int
+		stepsPerFrame int
+		lastFrameDuration time.Duration
+	}
+
+func (g *Game) Update() error {
+	startTime := time.Now()
+
+	for i := 0; i < g.stepsPerFrame; i++ {
+		err := cpu.step()
+		if err != nil {
+			log.Printf("Stopped by error at PC %08X",cpu.PC)
+			log.Print(err)
+			return Terminated
+		}
+
+		if cpu.stopped { return Terminated }
+
+		if idleCounter == 0 { break }
+	}
+	g.lastFrameDuration = time.Since(startTime)
+
+	return nil
+}
+
+func (g *Game) Draw(screen *ebiten.Image) {
+	screen.DrawImage(framebuffer.framebuffer, nil)
+
+	/*
+	buf := fmt.Sprintf("PC: %08X FP: %08X RP: %08X ESP: %2X\n%v", cpu.PC, cpu.FP, cpu.RP, cpu.ESP, g.lastFrameDuration)
+	ebitenutil.DebugPrint(screen, buf)
+
+	screen.Set(g.x, g.y, color.RGBA{255,0,0,0})
+	screen.Set(g.x, g.y+1, color.RGBA{0,255,0,0})
+	screen.Set(g.x, g.y+2, color.RGBA{0,255,255,0})
+	screen.Set(g.x, g.y+3, color.RGBA{255,255,255,0})
+	g.x += 1
+	if g.x > 319 { g.x = 0 }
+	*/
+
+	// if idleCounter == 0 { ebitenutil.DebugPrint(screen, "idle") }
+}
+
+func (g *Game) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHeight int) {
+	return 640, 400
+}
+
+func main() {
+	var codefile string = ""
+
+	addrPtr := flag.Int("a",0,"starting address")
+	tracePtr := flag.Bool("t",false,"trace")
+	cardImgPtr := flag.String("i", "sdcard.img", "SD card image file")
+	flag.Parse()
+	if len(flag.Args()) > 0 {
+		codefile = flag.Args()[0]
+	} else {
+		codefile = "rommon.prog"
+	}
+
+	log.SetFlags(0)
+	oldState, err := SetRawConsole()
+	if err != nil {
+		panic(err)
+	}
+	defer RestoreConsole(oldState)
+
+	cpu.initialize()
+	mem.initialize(4096 * 1024 / 4)
+
+	uart.cpu = &cpu
+	mem.attachIO(&uart, 0)
+
+	err = sdspi.openImage(*cardImgPtr)
+	if err != nil {
+		panic(err)
+	}
+	defer sdspi.closeImage()
+	//sdspi.debug = true
+	mem.attachIO(&sdspi, 1)
+
+	framebuffer.initialize()
+	mem.attachIO(&framebuffer, 2)
+
+	irqc.initialize()
+	mem.attachIO(&irqc, 3)
+
+	cpu.mem = &mem
+	cpu.PC = word(*addrPtr)
+
+	if codefile != "" {
+		mem.loadFromFile(codefile, *addrPtr)
+	}
+
+	consoleChan = make(chan byte)
+	uart.consoleChan = make(chan byte)
+
+	ebiten.SetWindowSize(800, 600)
+	ebiten.SetWindowTitle("Tridora Framebuffer")
+
+	g := Game{}
+	cpu.trace = *tracePtr
+	g.stepsPerFrame = 166666
+	// g.stepsPerFrame = 1
+
+	go func(ch chan byte) {
+		for {
+			buf := make([] byte,1);
+			n, err := ConsoleRead(buf)
+			if err != nil {
+				fmt.Println("read error on stdin, closing channel")
+				close(ch)
+				return
+			}
+			if n > 0 {ch <- buf[0] }
+		}
+	}(uart.consoleChan)
+
+	if err := ebiten.RunGame(&g); err != Terminated && err != nil {
+		log.Panic(err)
+	}
+}