gb_rom_load.java

package com.ferg.fergboy.memory;

import android.content.Context;
import android.content.res.AssetFileDescriptor;
import android.util.Log;

import java.nio.IntBuffer;
import java.io.*;

import org.apache.commons.io.IOUtils;

import com.ferg.fergboy.cpu.*;

public class Rom {
    private static final String TAG = "Rom";

    public byte[] romFile;
    public boolean inBios = true;
    // TODO: Current swappable bank selector

    private int[] bios = new int[] {
        0x31, 0xFE, 0xFF, 0xAF, 0x21, 0xFF, 0x9F, 0x32, 0xCB, 0x7C, 0x20, 0xFB, 0x21, 0x26, 0xFF, 0x0E,
        0x11, 0x3E, 0x80, 0x32, 0xE2, 0x0C, 0x3E, 0xF3, 0xE2, 0x32, 0x3E, 0x77, 0x77, 0x3E, 0xFC, 0xE0,
        0x47, 0x11, 0x04, 0x01, 0x21, 0x10, 0x80, 0x1A, 0xCD, 0x95, 0x00, 0xCD, 0x96, 0x00, 0x13, 0x7B,
        0xFE, 0x34, 0x20, 0xF3, 0x11, 0xD8, 0x00, 0x06, 0x08, 0x1A, 0x13, 0x22, 0x23, 0x05, 0x20, 0xF9,
        0x3E, 0x19, 0xEA, 0x10, 0x99, 0x21, 0x2F, 0x99, 0x0E, 0x0C, 0x3D, 0x28, 0x08, 0x32, 0x0D, 0x20,
        0xF9, 0x2E, 0x0F, 0x18, 0xF3, 0x67, 0x3E, 0x64, 0x57, 0xE0, 0x42, 0x3E, 0x91, 0xE0, 0x40, 0x04,
        0x1E, 0x02, 0x0E, 0x0C, 0xF0, 0x44, 0xFE, 0x90, 0x20, 0xFA, 0x0D, 0x20, 0xF7, 0x1D, 0x20, 0xF2,
        0x0E, 0x13, 0x24, 0x7C, 0x1E, 0x83, 0xFE, 0x62, 0x28, 0x06, 0x1E, 0xC1, 0xFE, 0x64, 0x20, 0x06,
        0x7B, 0xE2, 0x0C, 0x3E, 0x87, 0xF2, 0xF0, 0x42, 0x90, 0xE0, 0x42, 0x15, 0x20, 0xD2, 0x05, 0x20,
        0x4F, 0x16, 0x20, 0x18, 0xCB, 0x4F, 0x06, 0x04, 0xC5, 0xCB, 0x11, 0x17, 0xC1, 0xCB, 0x11, 0x17,
        0x05, 0x20, 0xF5, 0x22, 0x23, 0x22, 0x23, 0xC9, 0xCE, 0xED, 0x66, 0x66, 0xCC, 0x0D, 0x00, 0x0B,
        0x03, 0x73, 0x00, 0x83, 0x00, 0x0C, 0x00, 0x0D, 0x00, 0x08, 0x11, 0x1F, 0x88, 0x89, 0x00, 0x0E,
        0xDC, 0xCC, 0x6E, 0xE6, 0xDD, 0xDD, 0xD9, 0x99, 0xBB, 0xBB, 0x67, 0x63, 0x6E, 0x0E, 0xEC, 0xCC,
        0xDD, 0xDC, 0x99, 0x9F, 0xBB, 0xB9, 0x33, 0x3E, 0x3c, 0x42, 0xB9, 0xA5, 0xB9, 0xA5, 0x42, 0x4C,
        0x21, 0x04, 0x01, 0x11, 0xA8, 0x00, 0x1A, 0x13, 0xBE, 0x20, 0xFE, 0x23, 0x7D, 0xFE, 0x34, 0x20,
        0xF5, 0x06, 0x19, 0x78, 0x86, 0x23, 0x05, 0x20, 0xFB, 0x86, 0x20, 0xFE, 0x3E, 0x01, 0xE0, 0x50
    };

    private static Rom instance;
    public static Rom getInstance() {
        if (instance == null) {
            synchronized (Rom.class) {
                if (instance == null) {
                    instance = new Rom();
                }
            }
        }

        return instance;
    }

    public void loadFromFile(Context context, final String path) throws FileNotFoundException, IOException {
        InputStream fis = context.getResources().getAssets().open(path);
        romFile = IOUtils.toByteArray(fis);
    }

    public int readByte(int a) {
        if (a < 0x100 && inBios) {
            return bios[a];
        }

        if (a > 0xFF && inBios && (Z80.Registers.PC == 0x100)) {
            Log.i(TAG, "Finished BIOS");
            inBios = false;
        }

        return (int) romFile[a & 0xFFFF];
    }
}