6502
/
6502Android
mirror of https://github.com/felipecsl/6502Android.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Merge pull request #2 from felipecsl/felipe/mapper 

Initial implementation for Mapper 4
This commit is contained in:
Felipe Lima 2017-03-15 21:50:05 -07:00 committed by GitHub
parent 4a9bc14659 de61af751d
commit 3950fea47c
15 changed files with 392 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
app/build.gradle
View File

@ -14,6 +14,7 @@ android {
}
sourceSets {
main.java.srcDirs += 'src/main/kotlin'
test.java.srcDirs += 'src/test/kotlin'
}
testOptions {
unitTests.returnDefaultValues = true

4
app/src/main/kotlin/android/emu6502/CPU.kt
View File

@ -287,4 +287,8 @@ class CPU(val memory: Memory) : Display.Callbacks {
override fun onDraw() {
executionLock?.countDown()
}
fun triggerIRQ() {
throw NotImplementedError()
}
}

5
app/src/main/kotlin/android/emu6502/nes/APU.kt Normal file
View File

@ -0,0 +1,5 @@
package android.emu6502.nes
class APU {
}

12
app/src/main/kotlin/android/emu6502/nes/Cartridge.kt
View File

@ -4,14 +4,14 @@ import java.util.*
data class Cartridge(
// @formatter:off
val pgr: ByteArray, // PRG-ROM banks
val chr: ByteArray, // CHR-ROM banks
val mapper: Byte, // mapper type
val mirror: Byte, // mirroring mode
val battery: Byte // battery present
val pgr: IntArray, // PRG-ROM banks
val chr: IntArray, // CHR-ROM banks
val mapper: Byte, // mapper type
var mirror: Int, // mirroring mode
val battery: Byte, // battery present
val sram: IntArray = IntArray(0x2000) // Save RAM
// @formatter:on
) {
private val sram: ByteArray = ByteArray(0x2000) // Save RAM
override fun equals(other: Any?): Boolean {
if (this === other) return true

29
app/src/main/kotlin/android/emu6502/nes/Console.kt Normal file
View File

@ -0,0 +1,29 @@
package android.emu6502.nes
import android.emu6502.CPU
import android.emu6502.Display
import android.emu6502.Memory
import android.emu6502.nes.mappers.Mapper
class Console(
val cpu: CPU,
val apu: APU,
val ppu: PPU,
val cartridge: Cartridge,
val controller1: Controller,
val controller2: Controller,
val mapper: Mapper,
val ram: ByteArray = ByteArray(2048)
) {
companion object {
fun newConsole(cartridge: Cartridge, display: Display): Console {
val ppu = PPU()
val memory = Memory(display)
val cpu = CPU(memory)
val mapper = Mapper.newMapper(cartridge, ppu, cpu)
val apu = APU()
return Console(cpu, apu, ppu, cartridge, Controller(), Controller(), mapper)
}
}
}

5
app/src/main/kotlin/android/emu6502/nes/Controller.kt Normal file
View File

@ -0,0 +1,5 @@
package android.emu6502.nes
class Controller {
}

15
app/src/main/kotlin/android/emu6502/nes/INESFileParser.kt
View File

@ -27,13 +27,13 @@ internal class INESFileParser {
val inesFileHeader = parseFileHeader(stream)
// mapper type
val control1 = inesFileHeader.control1.toInt()
val mapper1 = control1.shr(4)
val mapper2 = inesFileHeader.control2.toInt().shr(4)
val mapper = if (mapper1 != 0) mapper1 else mapper2
val mapper1 = control1 shr 4
val mapper2 = inesFileHeader.control2.toInt() shr 4
val mapper = mapper1 or (mapper2 shl 4)
// mirroring type
val mirror1 = control1.and(1)
val mirror2 = control1.shr(3).and(1)
val mirror = if (mirror1 != 0) mirror1 else mirror2.shl(1)
val mirror1 = control1 and 1
val mirror2 = (control1 shr 3) and 1
val mirror = mirror1 or (mirror2 shl 1)
// battery-backed RAM
val battery = control1.shr(1).and(1).toByte()
// read prg-rom bank(s)
@ -42,7 +42,8 @@ internal class INESFileParser {
// read chr-rom bank(s)
val chr = ByteArray(inesFileHeader.numCHR.toInt() * 8192)
stream.read(chr)
return Cartridge(pgr, chr, mapper.toByte(), mirror.toByte(), battery)
return Cartridge(pgr.map(Byte::toInt).toIntArray(), chr.map(Byte::toInt).toIntArray(),
mapper.toByte(), mirror, battery)
}
}
}

47
app/src/main/kotlin/android/emu6502/nes/PPU.kt Normal file
View File

@ -0,0 +1,47 @@
package android.emu6502.nes
class PPU(
// @formatter:off
val cycle: Int = 0, // 0-340
val scanLine: Int = 0, // 0-261, 0-239=visible, 240=post, 241-260=vblank, 261=pre
val frame: Int = 0, // frame counter
// PPU registers
val v: Int = 0, // current vram address (15 bit)
val t: Int = 0, // temporary vram address (15 bit)
val x: Byte = 0, // fine x scroll (3 bit)
val w: Byte = 0, // write toggle (1 bit)
val f: Byte = 0, // even/odd frame flag (1 bit)
val register: Byte = 0,
// $2000 PPUCTRL
val flagNameTable: Boolean = false, // 0: $2000; 1: $2400; 2: $2800; 3: $2C00
val flagIncrement: Boolean = false, // 0: add 1; 1: add 32
val flagSpriteTable: Boolean = false, // 0: $0000; 1: $1000; ignored in 8x16 mode
val flagBackgroundTable: Boolean = false, // 0: $0000; 1: $1000
val flagSpriteSize: Boolean = false, // 0: 8x8; 1: 8x16
val flagMasterSlave: Boolean = false, // 0: read EXT; 1: write EXT
// $2001 PPUMASK
val flagGrayscale: Boolean = false, // 0: color; 1: grayscale
val flagShowLeftBackground: Boolean = false, // 0: hide; 1: show
val flagShowLeftSprites: Boolean = false, // 0: hide; 1: show
val flagShowBackground: Boolean = false, // 0: hide; 1: show
val flagShowSprites: Boolean = false, // 0: hide; 1: show
val flagRedTint: Boolean = false, // 0: normal; 1: emphasized
val flagGreenTint: Boolean = false, // 0: normal; 1: emphasized
val flagBlueTint: Boolean = false, // 0: normal; 1: emphasized
// $2002 PPUSTATUS
val flagSpriteZeroHit: Boolean = false,
val flagSpriteOverflow: Boolean = false,
// $2003 OAMADDR
val oamAddress: Byte = 0,
// $2007 PPUDATA
val bufferedData: Byte = 0 // for buffered reads
// @formatter:on
)

13
app/src/main/kotlin/android/emu6502/nes/mappers/AOROM.kt Normal file
View File

@ -0,0 +1,13 @@
package android.emu6502.nes.mappers
class AOROM : Mapper {
override fun write(address: Int, value: Int) {
}
override fun step() {
}
override fun read(address: Int): Int {
throw NotImplementedError()
}
}

13
app/src/main/kotlin/android/emu6502/nes/mappers/CNROM.kt Normal file
View File

@ -0,0 +1,13 @@
package android.emu6502.nes.mappers
class CNROM : Mapper {
override fun write(address: Int, value: Int) {
}
override fun step() {
}
override fun read(address: Int): Int {
throw NotImplementedError()
}
}

13
app/src/main/kotlin/android/emu6502/nes/mappers/MMC1.kt Normal file
View File

@ -0,0 +1,13 @@
package android.emu6502.nes.mappers
class MMC1 : Mapper {
override fun write(address: Int, value: Int) {
}
override fun step() {
}
override fun read(address: Int): Int {
throw NotImplementedError()
}
}

209
app/src/main/kotlin/android/emu6502/nes/mappers/MMC3.kt Normal file
View File

@ -0,0 +1,209 @@
package android.emu6502.nes.mappers
import android.emu6502.CPU
import android.emu6502.nes.Cartridge
import android.emu6502.nes.PPU
import android.emu6502.toHexString
// http://wiki.nesdev.com/w/index.php/MMC3
class MMC3(
private val cartridge: Cartridge,
private val ppu: PPU,
private val cpu: CPU
) : Mapper {
private var register: Int = 0
private var registers = IntArray(8)
private var prgMode: Int = 0
private var chrMode: Int = 0
private var prgOffsets = IntArray(4)
private var chrOffsets = IntArray(8)
private var reload: Int = 0
private var counter: Int = 0
private var irqEnable: Boolean = false
override fun read(address: Int): Int {
if (address < 0x2000) {
val bank = address / 0x0400
val offset = address % 0x0400
return cartridge.chr[chrOffsets[bank] + offset]
}
if (address >= 0x8000) {
val addr = address - 0x8000
val bank = addr / 0x2000
val offset = addr % 0x2000
return cartridge.pgr[prgOffsets[bank] + offset]
}
if (address >= 0x6000) {
return cartridge.sram[address - 0x6000]
}
throw RuntimeException("unhandled mapper4 read at address: ${address.toHexString()}")
}
override fun write(address: Int, value: Int) {
if (address < 0x2000) {
val bank = address / 0x0400
val offset = address % 0x0400
cartridge.chr[chrOffsets[bank] + offset] = value
} else if (address >= 0x8000) {
writeRegister(address, value)
} else if (address >= 0x6000) {
cartridge.sram[address - 0x6000] = value
} else {
throw RuntimeException("unhandled mapper4 write at address ${address.toHexString()}")
}
}
private fun writeRegister(address: Int, value: Int) {
if (address <= 0x9FFF && address % 2 == 0)
writeBankSelect(value)
else if (address <= 0x9FFF && address % 2 == 1)
writeBankData(value)
else if (address <= 0xBFFF && address % 2 == 0)
writeMirror(value)
else if (address <= 0xBFFF && address % 2 == 1)
writeProtect()
else if (address <= 0xDFFF && address % 2 == 0)
writeIRQLatch(value)
else if (address <= 0xDFFF && address % 2 == 1)
writeIRQReload()
else if (address <= 0xFFFF && address % 2 == 0)
writeIRQDisable()
else if (address <= 0xFFFF && address % 2 == 1)
writeIRQEnable()
}
private fun writeBankSelect(value: Int) {
prgMode = (value shr 6) and 1
chrMode = (value shr 7) and 1
register = value and 7
updateOffsets()
}
private fun updateOffsets() {
when (prgMode) {
0 -> {
prgOffsets[0] = prgBankOffset(registers[6])
prgOffsets[1] = prgBankOffset(registers[7])
prgOffsets[2] = prgBankOffset(-2)
prgOffsets[3] = prgBankOffset(-1)
}
1 -> {
prgOffsets[0] = prgBankOffset(-2)
prgOffsets[1] = prgBankOffset(registers[7])
prgOffsets[2] = prgBankOffset(registers[6])
prgOffsets[3] = prgBankOffset(-1)
}
}
when (chrMode) {
0 -> {
chrOffsets[0] = chrBankOffset(registers[0] and 0xFE)
chrOffsets[1] = chrBankOffset(registers[0] or 0x01)
chrOffsets[2] = chrBankOffset(registers[1] and 0xFE)
chrOffsets[3] = chrBankOffset(registers[1] or 0x01)
chrOffsets[4] = chrBankOffset(registers[2])
chrOffsets[5] = chrBankOffset(registers[3])
chrOffsets[6] = chrBankOffset(registers[4])
chrOffsets[7] = chrBankOffset(registers[5])
}
1 -> {
chrOffsets[0] = chrBankOffset(registers[2])
chrOffsets[1] = chrBankOffset(registers[3])
chrOffsets[2] = chrBankOffset(registers[4])
chrOffsets[3] = chrBankOffset(registers[5])
chrOffsets[4] = chrBankOffset(registers[0] and 0xFE)
chrOffsets[5] = chrBankOffset(registers[0] or 0x01)
chrOffsets[6] = chrBankOffset(registers[1] and 0xFE)
chrOffsets[7] = chrBankOffset(registers[1] or 0x01)
}
}
}
private fun chrBankOffset(index: Int): Int {
var idx = index
if (idx >= 0x80) {
idx -= 0x100
}
idx %= cartridge.chr.size / 0x0400
var offset = idx * 0x0400
if (offset < 0) {
offset += cartridge.chr.size
}
return offset
}
private fun prgBankOffset(index: Int): Int {
var idx = index
if (idx >= 0x80) {
idx -= 0x100
}
idx %= cartridge.chr.size / 0x2000
var offset = idx * 0x2000
if (offset < 0) {
offset += cartridge.chr.size
}
return offset
}
private fun writeBankData(value: Int) {
registers[register] = value
updateOffsets()
}
private fun writeMirror(value: Int) {
when (value and 1) {
0 -> cartridge.mirror = MirrorVertical
1 -> cartridge.mirror = MirrorHorizontal
}
}
private fun writeProtect() {
}
private fun writeIRQLatch(value: Int) {
reload = value
}
private fun writeIRQReload() {
counter = 0
}
private fun writeIRQDisable() {
irqEnable = false
}
private fun writeIRQEnable() {
irqEnable = true
}
override fun step() {
if (ppu.cycle != 280) { // TODO: this *should* be 260
return
}
if (ppu.scanLine in 240..260) {
return
}
if (!ppu.flagShowBackground && !ppu.flagShowSprites) {
return
}
handleScanLine()
}
private fun handleScanLine() {
if (counter == 0) {
counter = reload
} else {
counter--
if (counter == 0 && irqEnable) {
cpu.triggerIRQ()
}
}
}
companion object {
val MirrorHorizontal = 0
val MirrorVertical = 1
val MirrorSingle0 = 2
val MirrorSingle1 = 3
val MirrorFour = 4
}
}

19
app/src/main/kotlin/android/emu6502/nes/mappers/Mapper.kt Normal file
View File

@ -0,0 +1,19 @@
package android.emu6502.nes.mappers
import android.emu6502.CPU
import android.emu6502.nes.Cartridge
import android.emu6502.nes.PPU
interface Mapper {
fun read(address: Int): Int
fun write(address: Int, value: Int)
fun step()
companion object {
fun newMapper(cartridge: Cartridge, ppu: PPU, cpu: CPU): Mapper =
when (cartridge.mapper.toInt()) {
4 -> MMC3(cartridge, ppu, cpu)
else -> throw NotImplementedError()
}
}
}

13
app/src/main/kotlin/android/emu6502/nes/mappers/UNROM.kt Normal file
View File

@ -0,0 +1,13 @@
package android.emu6502.nes.mappers
class UNROM : Mapper {
override fun write(address: Int, value: Int) {
}
override fun step() {
}
override fun read(address: Int): Int {
throw NotImplementedError()
}
}

7
app/src/test/kotlin/android/emu6502/nes/INESFileParserTest.kt
View File

@ -28,4 +28,11 @@ class INESFileParserTest {
INESFileParser.INES_FILE_MAGIC, 0x10, 0x10, 0x40, 0x0, 0x0, INESFileParser.PADDING))
assertThat(header.isValid()).isTrue()
}
@Test fun testMapper() {
val testRom = javaClass.classLoader.getResource("roms/testrom.nes").toURI()
val cartridge = INESFileParser.parseCartridge(File(testRom))
// super mario bros 3 is Mapper 4 (MMC3)
assertThat(cartridge.mapper).isEqualTo(4)
}
}