6502/symon
1
0
Fork 0
mirror of https://github.com/sethm/symon.git synced 2024-06-07 19:29:27 +00:00
Code Issues Projects Releases Wiki Activity

rework SD controller emulation to work with Input- and OutputStreams (no longer load the image into a byte array)

Browse Source
This commit is contained in:
Maik Merten 2014-08-09 17:55:18 +02:00
parent c61a63d5bb
commit 7a215736fe
1 changed files with 68 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

97
src/main/java/com/loomcom/symon/devices/SdController.java
View File

@ -27,9 +27,9 @@ package com.loomcom.symon.devices;
import com.loomcom.symon.exceptions.MemoryAccessException;
import com.loomcom.symon.exceptions.MemoryRangeException;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
@ -48,34 +48,28 @@ public class SdController extends Device {
}
public static final int CONTROLLER_SIZE = 8;
private final int SECTOR_SIZE = 512;
private final static Logger logger = Logger.getLogger(SdController.class.getName());
private byte[] sdcontent;
private File sdImageFile;
private int lba0,lba1,lba2;
private int command;
private int position;
private Status status = Status.IDLE;
private final byte[] readBuffer = new byte[SECTOR_SIZE];
private final byte[] writeBuffer = new byte[SECTOR_SIZE];
private int readPosition = 0;
private int writePosition = 0;
public SdController(int address) throws MemoryRangeException {
super(address, address + CONTROLLER_SIZE - 1, "SDCONTROLLER");
// assume an empty 64K SD card by default
sdcontent = new byte[64 * 1024];
// try to load an actual SD card image
try {
FileInputStream fis = new FileInputStream(new File("sd.img"));
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buf = new byte[2048];
int read = fis.read(buf);
while(read > 0) {
baos.write(buf, 0, read);
read = fis.read(buf);
}
sdcontent = baos.toByteArray();
} catch (IOException ex) {
logger.log(Level.INFO, "Could not load image for SD card from file 'sd.img'");
sdImageFile = new File("sd.img");
if(!sdImageFile.exists()) {
sdImageFile = null;
logger.log(Level.INFO, "Could not find SD card image 'sd.img'");
}
}
@ -120,24 +114,70 @@ public class SdController extends Device {
this.position = lba0 + (lba1 << 8) + (lba2 << 16);
// each sector is 512 bytes, so multiply accordingly
this.position <<= 9;
}
}
private void prepareRead() {
this.status = Status.READ;
this.readPosition = 0;
computePosition();
if(sdImageFile != null) {
try {
FileInputStream fis = new FileInputStream(sdImageFile);
fis.skip(this.position);
int read = fis.read(readBuffer);
if(read < SECTOR_SIZE) {
logger.log(Level.WARNING, "not enough data to fill read buffer from SD image file");
}
fis.close();
} catch (IOException ex) {
logger.log(Level.WARNING, "could not fill read buffer from SD image file", ex);
}
}
}
private void prepareWrite() {
this.status = Status.WRITE;
this.writePosition = 0;
computePosition();
}
private int readData() {
if(status != Status.READ) {
return 0;
}
this.position %= this.sdcontent.length;
int data = this.sdcontent[this.position++];
if(this.position % 512 == 0) {
int data = readBuffer[readPosition++];
if(readPosition >= SECTOR_SIZE) {
this.status = Status.IDLE;
}
return data;
}
private void writeData(int data) {
this.position %= this.sdcontent.length;
this.sdcontent[this.position++] = (byte) data;
if(status != Status.WRITE) {
return;
}
writeBuffer[writePosition++] = (byte) data;
if(writePosition >= SECTOR_SIZE) {
if(sdImageFile != null) {
try {
FileOutputStream fos = new FileOutputStream(sdImageFile);
fos.write(writeBuffer, this.position, writeBuffer.length);
fos.close();
} catch (IOException ex) {
logger.log(Level.WARNING, "could not write data back to SD image file!", ex);
}
}
this.status = Status.IDLE;
}
}
private int readStatus() {
@ -155,15 +195,14 @@ public class SdController extends Device {
this.command = data;
switch(this.command) {
case 0 :
this.status = Status.READ;
prepareRead();
break;
case 1 :
this.status = Status.WRITE;
prepareWrite();
break;
default:
this.status = Status.IDLE;
}
computePosition();
}
@Override