001/*
002 *  This file is part of the Jikes RVM project (http://jikesrvm.org).
003 *
004 *  This file is licensed to You under the Eclipse Public License (EPL);
005 *  You may not use this file except in compliance with the License. You
006 *  may obtain a copy of the License at
007 *
008 *      http://www.opensource.org/licenses/eclipse-1.0.php
009 *
010 *  See the COPYRIGHT.txt file distributed with this work for information
011 *  regarding copyright ownership.
012 */
013package org.jikesrvm;
014
015import org.vmmagic.unboxed.*;
016
017/**
018 * Constants defining heap layout constants
019 */
020public final class HeapLayoutConstants {
021
022  /** The address of the start of the data section of the boot image. */
023  public static final Address BOOT_IMAGE_DATA_START =
024    Address.fromIntZeroExtend( 0x60000000 );
025
026  /** The address of the start of the code section of the boot image. */
027  public static final Address BOOT_IMAGE_CODE_START =
028    Address.fromIntZeroExtend( 0x64000000 );
029
030  /** The address of the start of the ref map section of the boot image. */
031  public static final Address BOOT_IMAGE_RMAP_START =
032    Address.fromIntZeroExtend( 0x67000000 );
033
034  /** The address in virtual memory that is the highest that can be mapped. */
035  public static final Address MAXIMUM_MAPPABLE =
036    Address.fromIntZeroExtend( 0xb0000000 );
037
038  /** The current boot image data size */
039  public static final int BOOT_IMAGE_DATA_SIZE = (BOOT_IMAGE_CODE_START.diff(BOOT_IMAGE_DATA_START).toInt());
040
041  /** The current boot image code size */
042  public static final int BOOT_IMAGE_CODE_SIZE = (BOOT_IMAGE_RMAP_START.diff(BOOT_IMAGE_CODE_START).toInt());
043
044  /**
045   * Limit for boot image data size: fail the build if
046   * {@link org.jikesrvm.Configuration#AllowOversizedImages VM.AllowOversizedImages}
047   * is not set and the boot image data size is greater than or equal to this amount
048   * of bytes.
049   */
050  public static final int BOOT_IMAGE_DATA_SIZE_LIMIT = 56 << 20;
051
052  /**
053   * Limit for boot image code size: fail the build if
054   * {@link org.jikesrvm.Configuration#AllowOversizedImages VM.AllowOversizedImages}
055   * is not set and the boot image code size is greater than or equal to this amount
056   * of bytes.
057   */
058  public static final int BOOT_IMAGE_CODE_SIZE_LIMIT = 24 << 20;
059
060  /* Typical compression ratio is about 1/20 */
061  public static final int BAD_MAP_COMPRESSION = 5;  // conservative heuristic
062  public static final int MAX_BOOT_IMAGE_RMAP_SIZE = BOOT_IMAGE_DATA_SIZE/BAD_MAP_COMPRESSION;
063
064  /** The address of the end of the data section of the boot image. */
065  public static final Address BOOT_IMAGE_DATA_END = BOOT_IMAGE_DATA_START.plus(BOOT_IMAGE_DATA_SIZE);
066  /** The address of the end of the code section of the boot image. */
067  public static final Address BOOT_IMAGE_CODE_END = BOOT_IMAGE_CODE_START.plus(BOOT_IMAGE_CODE_SIZE);
068  /** The address of the end of the ref map section of the boot image. */
069  public static final Address BOOT_IMAGE_RMAP_END = BOOT_IMAGE_RMAP_START.plus(MAX_BOOT_IMAGE_RMAP_SIZE);
070  /** The address of the end of the boot image. */
071  public static final Address BOOT_IMAGE_END = BOOT_IMAGE_RMAP_END;
072
073  private HeapLayoutConstants() {
074    // prevent instantiation
075  }
076
077}