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acobject.h revision 1.1.1.2
      1 
      2 /******************************************************************************
      3  *
      4  * Name: acobject.h - Definition of ACPI_OPERAND_OBJECT  (Internal object only)
      5  *
      6  *****************************************************************************/
      7 
      8 /*
      9  * Copyright (C) 2000 - 2011, Intel Corp.
     10  * All rights reserved.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions, and the following disclaimer,
     17  *    without modification.
     18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
     19  *    substantially similar to the "NO WARRANTY" disclaimer below
     20  *    ("Disclaimer") and any redistribution must be conditioned upon
     21  *    including a substantially similar Disclaimer requirement for further
     22  *    binary redistribution.
     23  * 3. Neither the names of the above-listed copyright holders nor the names
     24  *    of any contributors may be used to endorse or promote products derived
     25  *    from this software without specific prior written permission.
     26  *
     27  * Alternatively, this software may be distributed under the terms of the
     28  * GNU General Public License ("GPL") version 2 as published by the Free
     29  * Software Foundation.
     30  *
     31  * NO WARRANTY
     32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
     35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     42  * POSSIBILITY OF SUCH DAMAGES.
     43  */
     44 
     45 #ifndef _ACOBJECT_H
     46 #define _ACOBJECT_H
     47 
     48 /* acpisrc:StructDefs -- for acpisrc conversion */
     49 
     50 
     51 /*
     52  * The ACPI_OPERAND_OBJECT is used to pass AML operands from the dispatcher
     53  * to the interpreter, and to keep track of the various handlers such as
     54  * address space handlers and notify handlers. The object is a constant
     55  * size in order to allow it to be cached and reused.
     56  *
     57  * Note: The object is optimized to be aligned and will not work if it is
     58  * byte-packed.
     59  */
     60 #if ACPI_MACHINE_WIDTH == 64
     61 #pragma pack(8)
     62 #else
     63 #pragma pack(4)
     64 #endif
     65 
     66 /*******************************************************************************
     67  *
     68  * Common Descriptors
     69  *
     70  ******************************************************************************/
     71 
     72 /*
     73  * Common area for all objects.
     74  *
     75  * DescriptorType is used to differentiate between internal descriptors, and
     76  * must be in the same place across all descriptors
     77  *
     78  * Note: The DescriptorType and Type fields must appear in the identical
     79  * position in both the ACPI_NAMESPACE_NODE and ACPI_OPERAND_OBJECT
     80  * structures.
     81  */
     82 #define ACPI_OBJECT_COMMON_HEADER \
     83     union acpi_operand_object       *NextObject;        /* Objects linked to parent NS node */\
     84     UINT8                           DescriptorType;     /* To differentiate various internal objs */\
     85     UINT8                           Type;               /* ACPI_OBJECT_TYPE */\
     86     UINT16                          ReferenceCount;     /* For object deletion management */\
     87     UINT8                           Flags;
     88     /*
     89      * Note: There are 3 bytes available here before the
     90      * next natural alignment boundary (for both 32/64 cases)
     91      */
     92 
     93 /* Values for Flag byte above */
     94 
     95 #define AOPOBJ_AML_CONSTANT         0x01    /* Integer is an AML constant */
     96 #define AOPOBJ_STATIC_POINTER       0x02    /* Data is part of an ACPI table, don't delete */
     97 #define AOPOBJ_DATA_VALID           0x04    /* Object is intialized and data is valid */
     98 #define AOPOBJ_OBJECT_INITIALIZED   0x08    /* Region is initialized, _REG was run */
     99 #define AOPOBJ_SETUP_COMPLETE       0x10    /* Region setup is complete */
    100 #define AOPOBJ_INVALID              0x20    /* Host OS won't allow a Region address */
    101 
    102 
    103 /******************************************************************************
    104  *
    105  * Basic data types
    106  *
    107  *****************************************************************************/
    108 
    109 typedef struct acpi_object_common
    110 {
    111     ACPI_OBJECT_COMMON_HEADER
    112 
    113 } ACPI_OBJECT_COMMON;
    114 
    115 
    116 typedef struct acpi_object_integer
    117 {
    118     ACPI_OBJECT_COMMON_HEADER
    119     UINT8                           Fill[3];            /* Prevent warning on some compilers */
    120     UINT64                          Value;
    121 
    122 } ACPI_OBJECT_INTEGER;
    123 
    124 
    125 /*
    126  * Note: The String and Buffer object must be identical through the Pointer
    127  * and length elements.  There is code that depends on this.
    128  *
    129  * Fields common to both Strings and Buffers
    130  */
    131 #define ACPI_COMMON_BUFFER_INFO(_Type) \
    132     _Type                           *Pointer; \
    133     UINT32                          Length;
    134 
    135 
    136 typedef struct acpi_object_string   /* Null terminated, ASCII characters only */
    137 {
    138     ACPI_OBJECT_COMMON_HEADER
    139     ACPI_COMMON_BUFFER_INFO         (char)              /* String in AML stream or allocated string */
    140 
    141 } ACPI_OBJECT_STRING;
    142 
    143 
    144 typedef struct acpi_object_buffer
    145 {
    146     ACPI_OBJECT_COMMON_HEADER
    147     ACPI_COMMON_BUFFER_INFO         (UINT8)             /* Buffer in AML stream or allocated buffer */
    148     UINT32                          AmlLength;
    149     UINT8                           *AmlStart;
    150     ACPI_NAMESPACE_NODE             *Node;              /* Link back to parent node */
    151 
    152 } ACPI_OBJECT_BUFFER;
    153 
    154 
    155 typedef struct acpi_object_package
    156 {
    157     ACPI_OBJECT_COMMON_HEADER
    158     ACPI_NAMESPACE_NODE             *Node;              /* Link back to parent node */
    159     union acpi_operand_object       **Elements;         /* Array of pointers to AcpiObjects */
    160     UINT8                           *AmlStart;
    161     UINT32                          AmlLength;
    162     UINT32                          Count;              /* # of elements in package */
    163 
    164 } ACPI_OBJECT_PACKAGE;
    165 
    166 
    167 /******************************************************************************
    168  *
    169  * Complex data types
    170  *
    171  *****************************************************************************/
    172 
    173 typedef struct acpi_object_event
    174 {
    175     ACPI_OBJECT_COMMON_HEADER
    176     ACPI_SEMAPHORE                  OsSemaphore;        /* Actual OS synchronization object */
    177 
    178 } ACPI_OBJECT_EVENT;
    179 
    180 
    181 typedef struct acpi_object_mutex
    182 {
    183     ACPI_OBJECT_COMMON_HEADER
    184     UINT8                           SyncLevel;          /* 0-15, specified in Mutex() call */
    185     UINT16                          AcquisitionDepth;   /* Allow multiple Acquires, same thread */
    186     ACPI_MUTEX                      OsMutex;            /* Actual OS synchronization object */
    187     ACPI_THREAD_ID                  ThreadId;           /* Current owner of the mutex */
    188     struct acpi_thread_state        *OwnerThread;       /* Current owner of the mutex */
    189     union acpi_operand_object       *Prev;              /* Link for list of acquired mutexes */
    190     union acpi_operand_object       *Next;              /* Link for list of acquired mutexes */
    191     ACPI_NAMESPACE_NODE             *Node;              /* Containing namespace node */
    192     UINT8                           OriginalSyncLevel;  /* Owner's original sync level (0-15) */
    193 
    194 } ACPI_OBJECT_MUTEX;
    195 
    196 
    197 typedef struct acpi_object_region
    198 {
    199     ACPI_OBJECT_COMMON_HEADER
    200     UINT8                           SpaceId;
    201     ACPI_NAMESPACE_NODE             *Node;              /* Containing namespace node */
    202     union acpi_operand_object       *Handler;           /* Handler for region access */
    203     union acpi_operand_object       *Next;
    204     ACPI_PHYSICAL_ADDRESS           Address;
    205     UINT32                          Length;
    206 
    207 } ACPI_OBJECT_REGION;
    208 
    209 
    210 typedef struct acpi_object_method
    211 {
    212     ACPI_OBJECT_COMMON_HEADER
    213     UINT8                           InfoFlags;
    214     UINT8                           ParamCount;
    215     UINT8                           SyncLevel;
    216     union acpi_operand_object       *Mutex;
    217     UINT8                           *AmlStart;
    218     union
    219     {
    220         ACPI_INTERNAL_METHOD            Implementation;
    221         union acpi_operand_object       *Handler;
    222     } Dispatch;
    223 
    224     UINT32                          AmlLength;
    225     UINT8                           ThreadCount;
    226     ACPI_OWNER_ID                   OwnerId;
    227 
    228 } ACPI_OBJECT_METHOD;
    229 
    230 /* Flags for InfoFlags field above */
    231 
    232 #define ACPI_METHOD_MODULE_LEVEL        0x01    /* Method is actually module-level code */
    233 #define ACPI_METHOD_INTERNAL_ONLY       0x02    /* Method is implemented internally (_OSI) */
    234 #define ACPI_METHOD_SERIALIZED          0x04    /* Method is serialized */
    235 #define ACPI_METHOD_SERIALIZED_PENDING  0x08    /* Method is to be marked serialized */
    236 #define ACPI_METHOD_MODIFIED_NAMESPACE  0x10    /* Method modified the namespace */
    237 
    238 
    239 /******************************************************************************
    240  *
    241  * Objects that can be notified.  All share a common NotifyInfo area.
    242  *
    243  *****************************************************************************/
    244 
    245 /*
    246  * Common fields for objects that support ASL notifications
    247  */
    248 #define ACPI_COMMON_NOTIFY_INFO \
    249     union acpi_operand_object       *SystemNotify;      /* Handler for system notifies */\
    250     union acpi_operand_object       *DeviceNotify;      /* Handler for driver notifies */\
    251     union acpi_operand_object       *Handler;           /* Handler for Address space */
    252 
    253 
    254 typedef struct acpi_object_notify_common    /* COMMON NOTIFY for POWER, PROCESSOR, DEVICE, and THERMAL */
    255 {
    256     ACPI_OBJECT_COMMON_HEADER
    257     ACPI_COMMON_NOTIFY_INFO
    258 
    259 } ACPI_OBJECT_NOTIFY_COMMON;
    260 
    261 
    262 typedef struct acpi_object_device
    263 {
    264     ACPI_OBJECT_COMMON_HEADER
    265     ACPI_COMMON_NOTIFY_INFO
    266     ACPI_GPE_BLOCK_INFO             *GpeBlock;
    267 
    268 } ACPI_OBJECT_DEVICE;
    269 
    270 
    271 typedef struct acpi_object_power_resource
    272 {
    273     ACPI_OBJECT_COMMON_HEADER
    274     ACPI_COMMON_NOTIFY_INFO
    275     UINT32                          SystemLevel;
    276     UINT32                          ResourceOrder;
    277 
    278 } ACPI_OBJECT_POWER_RESOURCE;
    279 
    280 
    281 typedef struct acpi_object_processor
    282 {
    283     ACPI_OBJECT_COMMON_HEADER
    284 
    285     /* The next two fields take advantage of the 3-byte space before NOTIFY_INFO */
    286 
    287     UINT8                           ProcId;
    288     UINT8                           Length;
    289     ACPI_COMMON_NOTIFY_INFO
    290     ACPI_IO_ADDRESS                 Address;
    291 
    292 } ACPI_OBJECT_PROCESSOR;
    293 
    294 
    295 typedef struct acpi_object_thermal_zone
    296 {
    297     ACPI_OBJECT_COMMON_HEADER
    298     ACPI_COMMON_NOTIFY_INFO
    299 
    300 } ACPI_OBJECT_THERMAL_ZONE;
    301 
    302 
    303 /******************************************************************************
    304  *
    305  * Fields.  All share a common header/info field.
    306  *
    307  *****************************************************************************/
    308 
    309 /*
    310  * Common bitfield for the field objects
    311  * "Field Datum"  -- a datum from the actual field object
    312  * "Buffer Datum" -- a datum from a user buffer, read from or to be written to the field
    313  */
    314 #define ACPI_COMMON_FIELD_INFO \
    315     UINT8                           FieldFlags;         /* Access, update, and lock bits */\
    316     UINT8                           Attribute;          /* From AccessAs keyword */\
    317     UINT8                           AccessByteWidth;    /* Read/Write size in bytes */\
    318     ACPI_NAMESPACE_NODE             *Node;              /* Link back to parent node */\
    319     UINT32                          BitLength;          /* Length of field in bits */\
    320     UINT32                          BaseByteOffset;     /* Byte offset within containing object */\
    321     UINT32                          Value;              /* Value to store into the Bank or Index register */\
    322     UINT8                           StartFieldBitOffset;/* Bit offset within first field datum (0-63) */\
    323 
    324 
    325 typedef struct acpi_object_field_common                 /* COMMON FIELD (for BUFFER, REGION, BANK, and INDEX fields) */
    326 {
    327     ACPI_OBJECT_COMMON_HEADER
    328     ACPI_COMMON_FIELD_INFO
    329     union acpi_operand_object       *RegionObj;         /* Parent Operation Region object (REGION/BANK fields only) */
    330 
    331 } ACPI_OBJECT_FIELD_COMMON;
    332 
    333 
    334 typedef struct acpi_object_region_field
    335 {
    336     ACPI_OBJECT_COMMON_HEADER
    337     ACPI_COMMON_FIELD_INFO
    338     union acpi_operand_object       *RegionObj;         /* Containing OpRegion object */
    339 
    340 } ACPI_OBJECT_REGION_FIELD;
    341 
    342 
    343 typedef struct acpi_object_bank_field
    344 {
    345     ACPI_OBJECT_COMMON_HEADER
    346     ACPI_COMMON_FIELD_INFO
    347     union acpi_operand_object       *RegionObj;         /* Containing OpRegion object */
    348     union acpi_operand_object       *BankObj;           /* BankSelect Register object */
    349 
    350 } ACPI_OBJECT_BANK_FIELD;
    351 
    352 
    353 typedef struct acpi_object_index_field
    354 {
    355     ACPI_OBJECT_COMMON_HEADER
    356     ACPI_COMMON_FIELD_INFO
    357 
    358     /*
    359      * No "RegionObj" pointer needed since the Index and Data registers
    360      * are each field definitions unto themselves.
    361      */
    362     union acpi_operand_object       *IndexObj;          /* Index register */
    363     union acpi_operand_object       *DataObj;           /* Data register */
    364 
    365 } ACPI_OBJECT_INDEX_FIELD;
    366 
    367 
    368 /* The BufferField is different in that it is part of a Buffer, not an OpRegion */
    369 
    370 typedef struct acpi_object_buffer_field
    371 {
    372     ACPI_OBJECT_COMMON_HEADER
    373     ACPI_COMMON_FIELD_INFO
    374     union acpi_operand_object       *BufferObj;         /* Containing Buffer object */
    375 
    376 } ACPI_OBJECT_BUFFER_FIELD;
    377 
    378 
    379 /******************************************************************************
    380  *
    381  * Objects for handlers
    382  *
    383  *****************************************************************************/
    384 
    385 typedef struct acpi_object_notify_handler
    386 {
    387     ACPI_OBJECT_COMMON_HEADER
    388     ACPI_NAMESPACE_NODE             *Node;              /* Parent device */
    389     ACPI_NOTIFY_HANDLER             Handler;
    390     void                            *Context;
    391 
    392 } ACPI_OBJECT_NOTIFY_HANDLER;
    393 
    394 
    395 typedef struct acpi_object_addr_handler
    396 {
    397     ACPI_OBJECT_COMMON_HEADER
    398     UINT8                           SpaceId;
    399     UINT8                           HandlerFlags;
    400     ACPI_ADR_SPACE_HANDLER          Handler;
    401     ACPI_NAMESPACE_NODE             *Node;              /* Parent device */
    402     void                            *Context;
    403     ACPI_ADR_SPACE_SETUP            Setup;
    404     union acpi_operand_object       *RegionList;        /* regions using this handler */
    405     union acpi_operand_object       *Next;
    406 
    407 } ACPI_OBJECT_ADDR_HANDLER;
    408 
    409 /* Flags for address handler (HandlerFlags) */
    410 
    411 #define ACPI_ADDR_HANDLER_DEFAULT_INSTALLED  0x01
    412 
    413 
    414 /******************************************************************************
    415  *
    416  * Special internal objects
    417  *
    418  *****************************************************************************/
    419 
    420 /*
    421  * The Reference object is used for these opcodes:
    422  * Arg[0-6], Local[0-7], IndexOp, NameOp, RefOfOp, LoadOp, LoadTableOp, DebugOp
    423  * The Reference.Class differentiates these types.
    424  */
    425 typedef struct acpi_object_reference
    426 {
    427     ACPI_OBJECT_COMMON_HEADER
    428      UINT8                           Class;              /* Reference Class */
    429      UINT8                           TargetType;         /* Used for Index Op */
    430      UINT8                           Reserved;
    431      void                            *Object;            /* NameOp=>HANDLE to obj, IndexOp=>ACPI_OPERAND_OBJECT */
    432      ACPI_NAMESPACE_NODE             *Node;              /* RefOf or Namepath */
    433      union acpi_operand_object       **Where;            /* Target of Index */
    434      UINT32                          Value;              /* Used for Local/Arg/Index/DdbHandle */
    435 
    436 } ACPI_OBJECT_REFERENCE;
    437 
    438 /* Values for Reference.Class above */
    439 
    440 typedef enum
    441 {
    442     ACPI_REFCLASS_LOCAL             = 0,        /* Method local */
    443     ACPI_REFCLASS_ARG               = 1,        /* Method argument */
    444     ACPI_REFCLASS_REFOF             = 2,        /* Result of RefOf() TBD: Split to Ref/Node and Ref/OperandObj? */
    445     ACPI_REFCLASS_INDEX             = 3,        /* Result of Index() */
    446     ACPI_REFCLASS_TABLE             = 4,        /* DdbHandle - Load(), LoadTable() */
    447     ACPI_REFCLASS_NAME              = 5,        /* Reference to a named object */
    448     ACPI_REFCLASS_DEBUG             = 6,        /* Debug object */
    449 
    450     ACPI_REFCLASS_MAX               = 6
    451 
    452 } ACPI_REFERENCE_CLASSES;
    453 
    454 
    455 /*
    456  * Extra object is used as additional storage for types that
    457  * have AML code in their declarations (TermArgs) that must be
    458  * evaluated at run time.
    459  *
    460  * Currently: Region and FieldUnit types
    461  */
    462 typedef struct acpi_object_extra
    463 {
    464     ACPI_OBJECT_COMMON_HEADER
    465     ACPI_NAMESPACE_NODE             *Method_REG;        /* _REG method for this region (if any) */
    466     void                            *RegionContext;     /* Region-specific data */
    467     UINT8                           *AmlStart;
    468     UINT32                          AmlLength;
    469 
    470 } ACPI_OBJECT_EXTRA;
    471 
    472 
    473 /* Additional data that can be attached to namespace nodes */
    474 
    475 typedef struct acpi_object_data
    476 {
    477     ACPI_OBJECT_COMMON_HEADER
    478     ACPI_OBJECT_HANDLER             Handler;
    479     void                            *Pointer;
    480 
    481 } ACPI_OBJECT_DATA;
    482 
    483 
    484 /* Structure used when objects are cached for reuse */
    485 
    486 typedef struct acpi_object_cache_list
    487 {
    488     ACPI_OBJECT_COMMON_HEADER
    489     union acpi_operand_object       *Next;              /* Link for object cache and internal lists*/
    490 
    491 } ACPI_OBJECT_CACHE_LIST;
    492 
    493 
    494 /******************************************************************************
    495  *
    496  * ACPI_OPERAND_OBJECT Descriptor - a giant union of all of the above
    497  *
    498  *****************************************************************************/
    499 
    500 typedef union acpi_operand_object
    501 {
    502     ACPI_OBJECT_COMMON                  Common;
    503     ACPI_OBJECT_INTEGER                 Integer;
    504     ACPI_OBJECT_STRING                  String;
    505     ACPI_OBJECT_BUFFER                  Buffer;
    506     ACPI_OBJECT_PACKAGE                 Package;
    507     ACPI_OBJECT_EVENT                   Event;
    508     ACPI_OBJECT_METHOD                  Method;
    509     ACPI_OBJECT_MUTEX                   Mutex;
    510     ACPI_OBJECT_REGION                  Region;
    511     ACPI_OBJECT_NOTIFY_COMMON           CommonNotify;
    512     ACPI_OBJECT_DEVICE                  Device;
    513     ACPI_OBJECT_POWER_RESOURCE          PowerResource;
    514     ACPI_OBJECT_PROCESSOR               Processor;
    515     ACPI_OBJECT_THERMAL_ZONE            ThermalZone;
    516     ACPI_OBJECT_FIELD_COMMON            CommonField;
    517     ACPI_OBJECT_REGION_FIELD            Field;
    518     ACPI_OBJECT_BUFFER_FIELD            BufferField;
    519     ACPI_OBJECT_BANK_FIELD              BankField;
    520     ACPI_OBJECT_INDEX_FIELD             IndexField;
    521     ACPI_OBJECT_NOTIFY_HANDLER          Notify;
    522     ACPI_OBJECT_ADDR_HANDLER            AddressSpace;
    523     ACPI_OBJECT_REFERENCE               Reference;
    524     ACPI_OBJECT_EXTRA                   Extra;
    525     ACPI_OBJECT_DATA                    Data;
    526     ACPI_OBJECT_CACHE_LIST              Cache;
    527 
    528     /*
    529      * Add namespace node to union in order to simplify code that accepts both
    530      * ACPI_OPERAND_OBJECTs and ACPI_NAMESPACE_NODEs. The structures share
    531      * a common DescriptorType field in order to differentiate them.
    532      */
    533     ACPI_NAMESPACE_NODE                 Node;
    534 
    535 } ACPI_OPERAND_OBJECT;
    536 
    537 
    538 /******************************************************************************
    539  *
    540  * ACPI_DESCRIPTOR - objects that share a common descriptor identifier
    541  *
    542  *****************************************************************************/
    543 
    544 /* Object descriptor types */
    545 
    546 #define ACPI_DESC_TYPE_CACHED           0x01        /* Used only when object is cached */
    547 #define ACPI_DESC_TYPE_STATE            0x02
    548 #define ACPI_DESC_TYPE_STATE_UPDATE     0x03
    549 #define ACPI_DESC_TYPE_STATE_PACKAGE    0x04
    550 #define ACPI_DESC_TYPE_STATE_CONTROL    0x05
    551 #define ACPI_DESC_TYPE_STATE_RPSCOPE    0x06
    552 #define ACPI_DESC_TYPE_STATE_PSCOPE     0x07
    553 #define ACPI_DESC_TYPE_STATE_WSCOPE     0x08
    554 #define ACPI_DESC_TYPE_STATE_RESULT     0x09
    555 #define ACPI_DESC_TYPE_STATE_NOTIFY     0x0A
    556 #define ACPI_DESC_TYPE_STATE_THREAD     0x0B
    557 #define ACPI_DESC_TYPE_WALK             0x0C
    558 #define ACPI_DESC_TYPE_PARSER           0x0D
    559 #define ACPI_DESC_TYPE_OPERAND          0x0E
    560 #define ACPI_DESC_TYPE_NAMED            0x0F
    561 #define ACPI_DESC_TYPE_MAX              0x0F
    562 
    563 
    564 typedef struct acpi_common_descriptor
    565 {
    566     void                            *CommonPointer;
    567     UINT8                           DescriptorType; /* To differentiate various internal objs */
    568 
    569 } ACPI_COMMON_DESCRIPTOR;
    570 
    571 typedef union acpi_descriptor
    572 {
    573     ACPI_COMMON_DESCRIPTOR          Common;
    574     ACPI_OPERAND_OBJECT             Object;
    575     ACPI_NAMESPACE_NODE             Node;
    576     ACPI_PARSE_OBJECT               Op;
    577 
    578 } ACPI_DESCRIPTOR;
    579 
    580 #pragma pack()
    581 
    582 #endif /* _ACOBJECT_H */
    583