main.h

一个操作系统源代码 用于嵌入式设备 在Vc++环境下仿真 成功移植到多款处理器上

/*
 * Copyright (c) 1998-2001 Sun Microsystems, Inc. All Rights Reserved.
 *
 * This software is the confidential and proprietary information of Sun
 * Microsystems, Inc. ("Confidential Information").  You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with Sun.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
 * SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES
 * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
 * THIS SOFTWARE OR ITS DERIVATIVES.
 *
 */

/*=========================================================================
 * SYSTEM:    KVM
 * SUBSYSTEM: Main program; compilation options
 * FILE:      main.h
 * OVERVIEW:  Compilation options setup for fine-tuning the system
 *            and for enabling/disabling various execution, configuration,
 *            debugging, profiling and tracing options.
 * AUTHOR:    Antero Taivalsaari, Sun Labs
 *            Edited by Doug Simon 11/1998
 *            (and many others since then...)
 *=======================================================================*/

/*=========================================================================
 * This file gives the >>DEFAULT<< values for various compile time flags.
 *
 * Any port can override a value given in this file by either:
 *      - Giving it that value in its port-specific "machine_md.h" file
 *      - Giving it a value in a compiler-specific manner (e.g.,
 *        as a command line parameter in a makefile.)
 *
 * The preferred way of changing the values defined in this file
 * is to edit the port-specific "machine_md.h" file rather than
 * change the default values here.
 *=======================================================================*/

/*=========================================================================
 * General compilation options
 *=======================================================================*/

/*
 * Set this to zero if your compiler does not directly support 64-bit
 * integers.
 */
#ifndef COMPILER_SUPPORTS_LONG
#define COMPILER_SUPPORTS_LONG 1
#endif

/*
 * Set this to a non-zero value if your compiler requires that 64-bit
 * integers be aligned on 0 mod 8 boundaries.
 */
#ifndef NEED_LONG_ALIGNMENT
#define NEED_LONG_ALIGNMENT 0
#endif

/* Set this to a non-zero value if your compiler requires that double
 * precision floating-pointer numbers be aligned on 0 mod 8 boundaries.
 */
#ifndef NEED_DOUBLE_ALIGNMENT
#define NEED_DOUBLE_ALIGNMENT 0
#endif

/*=========================================================================
 * General system configuration options
 * (Note: many of these flags are commonly overridden from makefiles)
 *=======================================================================*/

/* Indicates whether floating point operations are supported or not.
 * Should be 0 in CLDC Specification compliant implementations.
 */
#ifndef IMPLEMENTS_FLOAT
#define IMPLEMENTS_FLOAT 0
#endif

/*
 * Turns class prelinking/preloading (JavaCodeCompact) support on or off.
 * If this option is on, KVM can prelink system classes into the
 * virtual machine executable, speeding up VM startup considerably.
 *
 * Note: This flag is commonly overridden from the makefile
 * in our Windows and Unix ports.
 * 
 * Note: To generate the necessary ROM images for Palm, go to 
 * directory "tools/jcc", and type "gnumake palm".
 */
#ifndef ROMIZING
#define ROMIZING 1
#endif

/*
 * Includes or excludes the optional Java Application Manager (JAM)
 * component in the virtual machine.  Refer to Porting Guide for
 * details.
 *
 * Note: This flag is commonly overridden from the makefile
 * in our Windows and Unix ports.
 */
#ifndef USE_JAM
#define USE_JAM 0
#endif

/* Indicates that this port utilizes asynchronous native functions.
 * Currently, this option is supported only on Win32.
 * Refer to KVM Porting Guide for details.
 */
#ifndef ASYNCHRONOUS_NATIVE_FUNCTIONS
#define ASYNCHRONOUS_NATIVE_FUNCTIONS 0
#endif

/*=========================================================================
 * Palm-related system configuration options
 *=======================================================================*/

/* This is a special feature intended mainly for the Palm and similar
 * implementations with limited dynamic memory.  Unix and Windows both
 * have "fakeStaticMemory.c", but that is intended only to help find bugs
 * in the Palm implementation.
 *
 * If set to a non-zero value, the implementation will try to move field
 * tables, method tables, and other immutable structures from dynamic memory
 * to "static memory" (storage RAM on Palm), which is easy to read but more
 * difficult to write. This frees up valuable space in dynamic RAM.
 */
#ifndef USESTATIC
#define USESTATIC 0
#endif

/* Instructs KVM to use an optimization which allows KVM to allocate
 * the Java heap in multiple chunks or segments. This makes it possible
 * to allocate more Java heap space on memory-constrained target
 * platforms such as the Palm.  This option is potentially useful
 * also on other target platforms with segmented memory architecture.
 */
#ifndef CHUNKY_HEAP
#define CHUNKY_HEAP 0
#endif

/* Instructs KVM to implement a compacting garbage collector
 * or to disable compaction. NOTE: Currently compaction cannot
 * be used on those platforms that have a segmented memory
 * architecture (e.g., Palm OS).
 */
#ifndef ENABLE_HEAP_COMPACTION
#define ENABLE_HEAP_COMPACTION !CHUNKY_HEAP
#endif

/* This is a special form of ROMIZING (JavaCodeCompacting) that is used
 * only by the Palm. It allows the rom'ed image to be relocatable even
 * after it is built.  The ROMIZING flag is commonly provided
 * as a command line parameter from a makefile.
 */
#ifndef RELOCATABLE_ROM
#define RELOCATABLE_ROM 0
#endif

/*=========================================================================
 * Memory allocation settings
 *=======================================================================*/

/*=========================================================================
 * COMMENT: The default sizes for overall memory allocation and
 * resource allocation for individual threads are defined here.
 *
 * As a general principle, KVM allocates all the memory it needs
 * upon virtual machine startup.  At runtime, all memory is allocated
 * from within these preallocated areas.  However, note that on
 * many platforms the native functions linked into the VM (e.g.,
 * graphics operations) often perform dynamic memory allocation
 * outside the Java heap.
 *=======================================================================*/

/* The Java heap size that KVM will allocate upon virtual machine
 * startup (in bytes).  Note that the Palm implementation ignores
 * this value and uses an alternative memory allocation strategy.
 *
 * Also note that this definition is commonly overridden from
 * the makefile in the Windows and Unix ports.
 */
#ifndef DEFAULTHEAPSIZE
#define DEFAULTHEAPSIZE 65024   /* 0xFE00 */
#endif

/* Maximum size of the master inline cache (# of ICACHE entries)
 * Remember that maximum size should not exceed 65535, because the
 * length of inlined bytecode parameters is only two bytes (see cache.h).
 * This macro is meaningful only if the ENABLEFASTBYTECODES option
 * is turned on.
 */
#ifndef INLINECACHESIZE
#define INLINECACHESIZE   100
#endif

/* The execution stacks of Java threads in KVM grow and shrink
 * at runtime. This value determines the default size of a new
 * stack frame chunk when more space is needed.
 */
#ifndef STACKCHUNKSIZE
#define STACKCHUNKSIZE    128
#endif

/* The size (in bytes) of a statically allocated area that the
 * virtual machine uses internally in various string operations.
 * See global.h and global.c.
 */
#ifndef STRINGBUFFERSIZE
#define STRINGBUFFERSIZE 512
#endif

/*=========================================================================
 * Garbage collection options
 *=======================================================================*/

/*
 * The following flag is for debugging. If non-zero, it'll cause a
 * garbage collection to happen before every memory allocation.
 * This will help find those pointers that you're forgetting to
 * lock!  Be sure to turn this option off for a production build.
 */
#ifndef EXCESSIVE_GARBAGE_COLLECTION
#define EXCESSIVE_GARBAGE_COLLECTION 0
#endif

/*=========================================================================
 * Interpreter execution options (KVM 1.0)
 *=======================================================================*/

/* Turns runtime bytecode replacement (and Deutsch-Schiffman style
 * inline caching) on/off.  The system will run faster with fast
 * bytecodes on, but needs a few kilobytes of extra space for
 * the additional code. Note that you can't use bytecode replacement
 * on those platforms in which bytecodes are stored in non-volatile
 * memory (e.g., ROM).  This option does not work on the Palm, because
 * we want to save memory and store bytecodes in storage/static memory.
 */
#ifndef ENABLEFASTBYTECODES
#define ENABLEFASTBYTECODES 0
#endif

/* This option can be used for turning on/off constant pool integrity