Developer CD Series 1998 January: Mac OS SDK/Dev.CD Jan 98 SDK1.toast/Development Kits (Disc 1)/Interfaces&Libraries/Universal/Interfaces/PInterfaces/PEFBinaryFormat.p

Text File | 1997-08-12 | 37.6 KB | 802 lines | [TEXT/MPS ]

{
     File:        PEFBinaryFormat.p

     Contains:    PEF Types and Macros

     Version:    Technology:    Master Interfaces
                 Release:    Universal Interfaces 3.0.1

     Copyright:    © 1993-1997 by Apple Computer, Inc., all rights reserved.

     Bugs?:        Please include the the file and version information (from above) with
                 the problem description.  Developers belonging to one of the Apple
                 developer programs can submit bug reports to:

                     [e-mail]

}


{$IFC UNDEFINED UsingIncludes}
{$SETC UsingIncludes := 0}
{$ENDC}

{$IFC NOT UsingIncludes}
 UNIT PEFBinaryFormat;
 INTERFACE
{$ENDC}

{$IFC UNDEFINED __PEFBINARYFORMAT__}
{$SETC __PEFBINARYFORMAT__ := 1}

{$I+}
{$SETC PEFBinaryFormatIncludes := UsingIncludes}
{$SETC UsingIncludes := 1}

{$IFC UNDEFINED __TYPES__}
{$I Types.p}
{$ENDC}


{$PUSH}
{$ALIGN MAC68K}
{$LibExport+}

{ -----------------------------------------------------------------------------------------    }
{ Almost all types are padded for natural alignment.  However the PEFExportedSymbol type is    }
{ 10 bytes long, containing two 32 bit fields and one 16 bit field.  Arrays of it must be        }
{ packed, so it requires "68K" alignment.  Setting this globally to 68K should also help        }
{ ensure consistent treatment across compilers.                                                }

{ ======================================================================================== }
{ Overall Structure }
{ ================= }

{ -------------------------------------------------------------------------------------------    }
{ This header contains a complete set of types and macros for dealing with the PEF executable    }
{ format.  While some description is provided, this header is not meant as a primary source    }
{ of documentation on PEF.  An excellent specification of PEF can be found in the Macintosh    }
{ Runtime Architectures book.  This header is primarily a physical format description.  Thus    }
{ it depends on as few other headers as possible and structure fields have obvious sizes.        }
{                                                                                                 }
{ The physical storage for a PEF executable is known as a "container".  This refers to just    }
{ the executable itself, not the file etc.  E.g. if five DLLs are packaged in a single file's    }
{ data fork, that one data fork has five containers within it.                                    }
{                                                                                                 }
{ A PEF container consists of an overall header, followed by one or more section headers,        }
{ followed by the section name table, followed by the contents for the sections.  Some kinds    }
{ of sections have specific internal representation.  The "loader" section is the most common    }
{ of these special sections.  It contains information on the exports, imports, and runtime        }
{ relocations required to prepare the executable.  PEF containers are self contained, all        }
{ portions are located via relative offsets.                                                    }
{                                                                                                 }
{                                                                                                 }
{            +-------------------------------+                                                    }
{            |        Container Header        |    40 bytes                                        }
{            +-------------------------------+                                                    }
{            |        Section 0 header        |    28 bytes each                                    }
{            |...............................|                                                    }
{            |            - - - -                |                                                    }
{            |...............................|                                                    }
{            |        Section n-1 header        |                                                    }
{            +-------------------------------+                                                    }
{            |        Section Name Table        |                                                    }
{            +-------------------------------+                                                    }
{            |        Section x raw data        |                                                    }
{            +-------------------------------+                                                    }
{             |            - - - -                |                                                    }
{            +-------------------------------+                                                    }
{            |        Section y raw data        |                                                    }
{            +-------------------------------+                                                    }
{                                                                                                 }
{                                                                                                 }
{ The sections are implicitly numbered from 0 to n according to the order of their headers.    }
{ The headers of the instantiated sections must precede those of the non-instantiated            }
{ sections.  The ordering of the raw data is independent of the section header ordering.        }
{ Each section header contains the offset for that section's raw data.                            }

{ =========================================================================================== }
{ Container Header }
{ ================ }


TYPE
    PEFContainerHeaderPtr = ^PEFContainerHeader;
    PEFContainerHeader = RECORD
        tag1:                    OSType;                                    {  Must contain 'Joy!'.  }
        tag2:                    OSType;                                    {  Must contain 'peff'.  (Yes, with two 'f's.)  }
        architecture:            OSType;                                    {  The ISA for code sections.  Constants in CodeFragments.h.  }
        formatVersion:            UInt32;                                    {  The physical format version.  }
        dateTimeStamp:            UInt32;                                    {  Macintosh format creation/modification stamp.  }
        oldDefVersion:            UInt32;                                    {  Old definition version number for the code fragment.  }
        oldImpVersion:            UInt32;                                    {  Old implementation version number for the code fragment.  }
        currentVersion:            UInt32;                                    {  Current version number for the code fragment.  }
        sectionCount:            UInt16;                                    {  Total number of section headers that follow.  }
        instSectionCount:        UInt16;                                    {  Number of instantiated sections.  }
        reservedA:                UInt32;                                    {  Reserved, must be written as zero.  }
    END;


CONST
    kPEFTag1                    = 'Joy!';                        {  For non-Apple compilers: 0x4A6F7921.  }
    kPEFTag2                    = 'peff';                        {  For non-Apple compilers: 0x70656666.  }
    kPEFVersion                    = $00000001;


    kPEFFirstSectionHeaderOffset = 40;


{ =========================================================================================== }
{ Section Headers }
{ =============== }


TYPE
    PEFSectionHeaderPtr = ^PEFSectionHeader;
    PEFSectionHeader = RECORD
        nameOffset:                SInt32;                                    {  Offset of name within the section name table, -1 => none.  }
        defaultAddress:            UInt32;                                    {  Default address, affects relocations.  }
        totalLength:            UInt32;                                    {  Fully expanded size in bytes of the section contents.  }
        unpackedLength:            UInt32;                                    {  Size in bytes of the "initialized" part of the contents.  }
        containerLength:        UInt32;                                    {  Size in bytes of the raw data in the container.  }
        containerOffset:        UInt32;                                    {  Offset of section's raw data.  }
        sectionKind:            SInt8;                                    {  Kind of section contents/usage.  }
        shareKind:                SInt8;                                    {  Sharing level, if a writeable section.  }
        alignment:                SInt8;                                    {  Preferred alignment, expressed as log 2.  }
        reservedA:                SInt8;                                    {  Reserved, must be zero.  }
    END;


CONST
                                                                {  Values for the sectionKind field.  }
                                                                {     Section kind values for instantiated sections.  }
    kPEFCodeSection                = 0;                            {  Code, presumed pure & position independent.  }
    kPEFUnpackedDataSection        = 1;                            {  Unpacked writeable data.  }
    kPEFPackedDataSection        = 2;                            {  Packed writeable data.  }
    kPEFConstantSection            = 3;                            {  Read-only data.  }
    kPEFExecDataSection            = 6;                            {  Intermixed code and writeable data.  }
                                                                {  Section kind values for non-instantiated sections.  }
    kPEFLoaderSection            = 4;                            {  Loader tables.  }
    kPEFDebugSection            = 5;                            {  Reserved for future use.  }
    kPEFExceptionSection        = 7;                            {  Reserved for future use.  }
    kPEFTracebackSection        = 8;                            {  Reserved for future use.  }


                                                                {  Values for the shareKind field.  }
    kPEFProcessShare            = 1;                            {  Shared within a single process.  }
    kPEFGlobalShare                = 4;                            {  Shared across the entire system.  }
    kPEFProtectedShare            = 5;                            {  Readable across the entire system, writeable only to privileged code.  }


{ =========================================================================================== }
{ Packed Data Contents }
{ ==================== }

{ -------------------------------------------------------------------------------------------    }
{ The raw contents of a packed data section are a sequence of byte codes.  The basic format    }
{ has a 3 bit opcode followed by a 5 bit count.  Additional bytes might be used to contain        }
{ counts larger than 31, and to contain a second or third count.  Further additional bytes        }
{ contain actual data values to transfer.                                                        }
{                                                                                                 }
{ All counts are represented in a variable length manner.  A zero in the initial 5 bit count    }
{ indicates the actual value follows.  In this case, and for the second and third counts, the    }
{ count is represented as a variable length sequence of bytes.  The bytes are stored in big    }
{ endian manner, most significant part first.  The high order bit is set in all but the last    }
{ byte.  The value is accumulated by shifting the current value up 7 bits and adding in the    }
{ low order 7 bits of the next byte.                                                            }

                                                                {  The packed data opcodes.  }
    kPEFPkDataZero                = 0;                            {  Zero fill "count" bytes.  }
    kPEFPkDataBlock                = 1;                            {  Block copy "count" bytes.  }
    kPEFPkDataRepeat            = 2;                            {  Repeat "count" bytes "count2"+1 times.  }
    kPEFPkDataRepeatBlock        = 3;                            {  Interleaved repeated and unique data.  }
    kPEFPkDataRepeatZero        = 4;                            {  Interleaved zero and unique data.  }


    kPEFPkDataOpcodeShift        = 5;
    kPEFPkDataCount5Mask        = $1F;
    kPEFPkDataMaxCount5            = 31;
    kPEFPkDataVCountShift        = 7;
    kPEFPkDataVCountMask        = $7F;
    kPEFPkDataVCountEndMask        = $80;



{ ------------------------------------------------------------------------------------------    }
{ The following code snippet can be used to input a variable length count.                        }
{                                                                                                 }
{        count = 0;                                                                                }
{        do (                                                                                    }
{            byte = *bytePtr++;                                                                    }
{            count = (count << kPEFPkDataVCountShift) | (byte & kPEFPkDataVCountMask);            }
{        ) while ( (byte & kPEFPkDataVCountEndMask) != 0 );                                        }
{                                                                                                 }
{ The following code snippet can be used to output a variable length count to a byte array.    }
{ This is more complex than the input code because the chunks are output in big endian order.    }
{ Think about handling values like 0 or 0x030000.                                                }
{                                                                                                 }
{        count = 1;.                                                                                }
{        tempValue = value >> kPEFPkDataCountShift;                                                }
{        while ( tempValue != 0 ) (                                                                }
{            count += 1;                                                                            }
{            tempValue = tempValue >> kPEFPkDataCountShift;                                        }
{        )                                                                                        }
{                                                                                                 }
{        bytePtr += count;                                                                        }
{        tempPtr = bytePtr - 1;                                                                    }
{        *tempPtr-- = value;        // ! No need to mask, only the low order byte is stored.        }
{        for ( count -= 1; count != 0; count -= 1 ) (                                            }
{            value = value >> kPEFPkDataCountShift;                                                }
{            *tempPtr-- = value | kPEFPkDataCountEndMask;                                        }
{        )                                                                                        }

{ =========================================================================================== }
{ Loader Section }
{ ============== }

{ ------------------------------------------------------------------------------------------    }
{ The loader section contains information needed to prepare the code fragment for execution.    }
{ This includes this fragment's exports, the import libraries and the imported symbols from    }
{ each library, and the relocations for the writeable sections.                                }
{                                                                                                 }
{            +-----------------------------------+                <-- containerOffset --------+    }
{            |        Loader Info Header            |    56 bytes                                |    }
{            |-----------------------------------|                                            |    }
{            |        Imported Library 0            |    24 bytes each                            |    }
{            |...................................|                                            |    }
{            |            - - -                    |                                            |    }
{            |...................................|                                            |    }
{            |        Imported Library l-1        |                                            |    }
{            |-----------------------------------|                                            |    }
{            |        Imported Symbol 0            |    4 bytes each                            |    }
{            |...................................|                                            |    }
{            |            - - -                    |                                            |    }
{            |...................................|                                            |    }
{            |         Imported Symbol i-1            |                                            |    }
{            |-----------------------------------|                                            |    }
{            |        Relocation Header 0            |    12 bytes each                            |    }
{            |...................................|                                            |    }
{            |            - - -                    |                                            |    }
{            |...................................|                                            |    }
{            |        Relocation Header r-1        |                                            |    }
{            |-----------------------------------|                <-- + relocInstrOffset -----|    }
{            |        Relocation Instructions        |                                            |    }
{            |-----------------------------------|                <-- + loaderStringsOffset --|    }
{            |        Loader String Table            |                                            |    }
{            |-----------------------------------|                <-- + exportHashOffset -----+    }
{            |        Export Hash Slot 0            |    4 bytes each                                }
{            |...................................|                                                }
{            |            - - -                    |                                                }
{            |...................................|                                                }
{            |         Export Hash Slot h-1        |                                                }
{            |-----------------------------------|                                                }
{            |        Export Symbol Key 0            |    4 bytes each                                }
{            |...................................|                                                }
{            |            - - -                    |                                                }
{            |...................................|                                                }
{            |        Export Symbol Key e-1        |                                                }
{            |-----------------------------------|                                                }
{            |        Export Symbol 0                |    10 bytes each                                }
{            |...................................|                                                }
{            |            - - -                    |                                                }
{            |...................................|                                                }
{            |        Export Symbol e-1            |                                                }
{            +-----------------------------------+                                                }


TYPE
    PEFLoaderInfoHeaderPtr = ^PEFLoaderInfoHeader;
    PEFLoaderInfoHeader = RECORD
        mainSection:            SInt32;                                    {  Section containing the main symbol, -1 => none.  }
        mainOffset:                UInt32;                                    {  Offset of main symbol.  }
        initSection:            SInt32;                                    {  Section containing the init routine's TVector, -1 => none.  }
        initOffset:                UInt32;                                    {  Offset of the init routine's TVector.  }
        termSection:            SInt32;                                    {  Section containing the term routine's TVector, -1 => none.  }
        termOffset:                UInt32;                                    {  Offset of the term routine's TVector.  }
        importedLibraryCount:    UInt32;                                    {  Number of imported libraries.  ('l')  }
        totalImportedSymbolCount: UInt32;                                {  Total number of imported symbols.  ('i')  }
        relocSectionCount:        UInt32;                                    {  Number of sections with relocations.  ('r')  }
        relocInstrOffset:        UInt32;                                    {  Offset of the relocation instructions.  }
        loaderStringsOffset:    UInt32;                                    {  Offset of the loader string table.  }
        exportHashOffset:        UInt32;                                    {  Offset of the export hash table.  }
        exportHashTablePower:    UInt32;                                    {  Export hash table size as log 2.  (Log2('h'))  }
        exportedSymbolCount:    UInt32;                                    {  Number of exported symbols.  ('e')  }
    END;

{ =========================================================================================== }
{ Imported Libraries }
{ ------------------ }
    PEFImportedLibraryPtr = ^PEFImportedLibrary;
    PEFImportedLibrary = RECORD
        nameOffset:                UInt32;                                    {  Loader string table offset of library's name.  }
        oldImpVersion:            UInt32;                                    {  Oldest compatible implementation version.  }
        currentVersion:            UInt32;                                    {  Current version at build time.  }
        importedSymbolCount:    UInt32;                                    {  Imported symbol count for this library.  }
        firstImportedSymbol:    UInt32;                                    {  Index of first imported symbol from this library.  }
        options:                SInt8;                                    {  Option bits for this library.  }
        reservedA:                SInt8;                                    {  Reserved, must be zero.  }
        reservedB:                UInt16;                                    {  Reserved, must be zero.  }
    END;


CONST
                                                                {  Bits for the PEFImportedLibrary options field.  }
    kPEFWeakImportLibMask        = $40;                            {  The imported library is allowed to be missing.  }
    kPEFInitLibBeforeMask        = $80;                            {  The imported library must be initialized first.  }


{ =========================================================================================== }
{ Imported Symbols }
{ ---------------- }

{ -------------------------------------------------------------------------------------------    }
{ The PEFImportedSymbol type has the following bit field layout.                                }
{                                                                                                 }
{                                                                       3                        }
{         0             7 8                                             1                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                        }
{      | symbol class  | offset of symbol name in loader string table  |                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                        }
{        |<-- 8 bits --->|<-- 24 bits ---------------------------------->|                        }


TYPE
    PEFImportedSymbolPtr = ^PEFImportedSymbol;
    PEFImportedSymbol = RECORD
        classAndName:            UInt32;
    END;


CONST
    kPEFImpSymClassShift        = 24;
    kPEFImpSymNameOffsetMask    = $00FFFFFF;
    kPEFImpSymMaxNameOffset        = $00FFFFFF;                    {  16,777,215  }


                                                                {  Imported and exported symbol classes.  }
    kPEFCodeSymbol                = $00;
    kPEFDataSymbol                = $01;
    kPEFTVectorSymbol            = $02;
    kPEFTOCSymbol                = $03;
    kPEFGlueSymbol                = $04;
    kPEFUndefinedSymbol            = $0F;
    kPEFWeakImportSymMask        = $80;


{ =========================================================================================== }
{ Exported Symbol Hash Table }
{ -------------------------- }

{ -------------------------------------------------------------------------------------------    }
{ Exported symbols are described in four parts, optimized for speed of lookup.  These parts    }
{ are the "export hash table", the "export key table", the "export symbol table", and the        }
{ "export name table".  Overall they contain a flattened representation of a fairly normal        }
{ hashed symbol table.                                                                            }
{                                                                                                }
{ The export hash table is an array of small fixed size elements.  The number of elements is    }
{ a power of 2.  A 32 bit hash word for a symbol is converted into an index into this array.    }
{ Each hash slot contains a count of the number of exported symbols that map to this slot and    }
{ the index of the first of those symbols in the key and symbol tables.  Of course some hash    }
{ slots will have a zero count.                                                                }
{                                                                                                }
{ The key and symbol tables are also arrays of fixed size elements, one for each exported        }
{ symbol.  Their entries are grouped by hash slot, those elements mapping to the same hash        }
{ slot are contiguous.  The key table contains just the full 32 bit hash word for each            }
{ exported symbol.  The symbol table contains the offset of the symbol's name in the string    }
{ table and other information about the exported symbol.                                        }
{                                                                                                }
{ To look up an export you take the hashword and compute the hash slot index.  You then scan    }
{ the indicated portion of the key table for matching hashwords.  If a hashword matches, you    }
{ look at the corresponding symbol table entry to find the full symbol name.  If the names        }
{ match the symbol is found.                                                                    }

{ -------------------------------------------------------------------------------------------    }
{ The following function may be used to compute the hash table size.  Signed values are used    }
{ just to avoid potential code generation overhead for unsigned division.                        }
{                                                                                                 }
{        UInt8    PEFComputeHashTableExponent    ( SInt32    exportCount )                            }
{        (                                                                                        }
{            SInt32    exponent;                                                                    }
{                                                                                                 }
{            const SInt32    kExponentLimit        = 16;    // Arbitrary, but must not exceed 30.    }
{            const SInt32    kAverageChainLimit    = 10;    // Arbitrary, for space/time tradeoff.    }
{                                                                                                 }
{            for ( exponent = 0; exponent < kExponentLimit; exponent += 1 ) (                    }
{                if ( (exportCount / (1 << exponent)) < kAverageChainLimit ) break;                }
{            )                                                                                    }
{                                                                                                 }
{            return exponent;                                                                    }
{                                                                                                 }
{        )    // PEFComputeHashTableExponent ()                                                    }

{ -------------------------------------------------------------------------------------------    }
{ The PEFExportedSymbolHashSlot type has the following bit field layout.                        }
{                                                                                                 }
{                                   1 1                                 3                        }
{         0                         3 4                                 1                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                        }
{        | symbol count              | index of first export key         |                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                        }
{        |<-- 14 bits -------------->|<-- 18 bits ---------------------->|                        }


TYPE
    PEFExportedSymbolHashSlotPtr = ^PEFExportedSymbolHashSlot;
    PEFExportedSymbolHashSlot = RECORD
        countAndStart:            UInt32;
    END;


CONST
    kPEFHashSlotSymCountShift    = 18;
    kPEFHashSlotFirstKeyMask    = $0003FFFF;
    kPEFHashSlotMaxSymbolCount    = $00003FFF;                    {   16,383  }
    kPEFHashSlotMaxKeyIndex        = $0003FFFF;                    {  262,143  }


{ =========================================================================================== }
{ Exported Symbol Hash Key }
{ ------------------------ }


TYPE
    PEFSplitHashWordPtr = ^PEFSplitHashWord;
    PEFSplitHashWord = RECORD
        nameLength:                UInt16;
        hashValue:                UInt16;
    END;

    PEFExportedSymbolKeyPtr = ^PEFExportedSymbolKey;
    PEFExportedSymbolKey = RECORD
        CASE INTEGER OF
        0: (
            fullHashWord:        UInt32;
            );
        1: (
            splitHashWord:        PEFSplitHashWord;
            );
    END;


CONST
    kPEFHashLengthShift            = 16;
    kPEFHashValueMask            = $0000FFFF;
    kPEFHashMaxLength            = $0000FFFF;                    {  65,535  }


{ -------------------------------------------------------------------------------------------            }
{ The following function computes the full 32 bit hash word.                                            }
{                                                                                                         }
{        UInt32    PEFComputeHashWord    ( BytePtr    nameText,        // ! First "letter", not length byte.    }
{                                      UInt32    nameLength )    // ! The text may be zero terminated.    }
{        (                                                                                                }
{            BytePtr    charPtr        = nameText;                                                                }
{            SInt32    hashValue    = 0;        // ! Signed to match old published algorithm.                }
{            UInt32    length        = 0;                                                                    }
{            UInt32    limit;                                                                                }
{            UInt32    result;                                                                                }
{            UInt8    currChar;                                                                            }
{                                                                                                         }
{            #define PseudoRotate(x)  ( ( (x) << 1 ) - ( (x) >> 16 ) )                                    }
{                                                                                                         }
{            for ( limit = nameLength; limit > 0; limit -= 1 ) (                                            }
{                currChar = *charPtr++;                                                                    }
{                if ( currChar == NULL ) break;                                                            }
{                length += 1;                                                                            }
{                hashValue = PseudoRotate ( hashValue ) ^ currChar;                                        }
{            )                                                                                            }
{                                                                                                         }
{            result    = (length << kPEFHashLengthShift) |                                                    }
{                      ((UInt16) ((hashValue ^ (hashValue >> 16)) & kPEFHashValueMask));                    }
{                                                                                                         }
{            return result;                                                                                }
{                                                                                                         }
{        )    // PEFComputeHashWord ()                                                                    }

{ =========================================================================================== }
{ Exported Symbols }
{ ---------------- }


TYPE
    PEFExportedSymbolPtr = ^PEFExportedSymbol;
    PEFExportedSymbol = RECORD
                                                                        {  ! This structure is 10 bytes long and arrays are packed.  }
        classAndName:            UInt32;                                    {  A combination of class and name offset.  }
        symbolValue:            UInt32;                                    {  Typically the symbol's offset within a section.  }
        sectionIndex:            SInt16;                                    {  The index of the section, or pseudo-section, for the symbol.  }
    END;

{ -------------------------------------------------------------------------------------------    }
{ The classAndName field of the PEFExportedSymbol type has the following bit field layout.        }
{                                                                                                 }
{                                                                       3                        }
{         0             7 8                                             1                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                        }
{      | symbol class  | offset of symbol name in loader string table  |                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                        }
{        |<-- 8 bits --->|<-- 24 bits ---------------------------------->|                        }


CONST
    kPEFExpSymClassShift        = 24;
    kPEFExpSymNameOffsetMask    = $00FFFFFF;
    kPEFExpSymMaxNameOffset        = $00FFFFFF;                    {  16,777,215  }


                                                                {  Negative section indices indicate pseudo-sections.  }
    kPEFAbsoluteExport            = -2;                            {  The symbol value is an absolute address.  }
    kPEFReexportedImport        = -3;                            {  The symbol value is the index of a reexported import.  }


{ =========================================================================================== }
{ Loader Relocations }
{ ================== }

{ -------------------------------------------------------------------------------------------    }
{ The relocations for a section are defined by a sequence of instructions for an abstract        }
{ machine that is specifically geared to performing relocations commonly needed for the "CFM"    }
{ code generation model.  These instructions occur in 16 bit chunks.  Most instructions have    }
{ just a single chunk.  Instructions that are larger than 16 bits have an opcode and some of    }
{ the operands in the first chunk, with other operands in following chunks.                    }


TYPE
    PEFRelocChunk                        = UInt16;
    PEFLoaderRelocationHeaderPtr = ^PEFLoaderRelocationHeader;
    PEFLoaderRelocationHeader = RECORD
        sectionIndex:            UInt16;                                    {  Index of the section to be fixed up.  }
        reservedA:                UInt16;                                    {  Reserved, must be zero.  }
        relocCount:                UInt32;                                    {  Number of 16 bit relocation chunks.  }
        firstRelocOffset:        UInt32;                                    {  Offset of first relocation instruction.  }
    END;

{ -------------------------------------------------------------------------------------------    }
{ ! Note that the relocCount field is the number of 16 bit relocation chunks, i.e. 1/2 the        }
{ ! total number of bytes of relocation instructions.  While most relocation instructions are    }
{ ! 16 bits long, some are longer so the number of complete relocation instructions may be        }
{ ! less than the relocCount value.                                                            }

{ ----------------------------------------------------------------------------------    }
{ The PEFRelocField macro is a utility for extracting relocation instruction fields.    }

{ =========================================================================================== }
{ Basic Relocation Opcodes }
{ ------------------------ }
{ ------------------------------------------------------------------------------------------    }
{ The number of opcode bits varies from 2 to 7.  The enumeration and switch table given here    }
{ are defined in terms of the most significant 7 bits of the first instruction chunk.  An        }
{ instruction is decoded by using the most significant 7 bits as an index into the opcode        }
{ table, which in turn contains appropriately masked forms of the most significant 7 bits.        }
{ The macro PEFRelocBasicOpcode assumes a declaration of the form.                                }
{                                                                                                 }
{        UInt8 kPEFRelocBasicOpcodes [kPEFRelocBasicOpcodeRange] = ( PEFMaskedBasicOpcodes );    }


CONST
    kPEFRelocBasicOpcodeRange    = 128;


{ -------------------------------------------------------------------------------------------    }
{ The relocation opcodes, clustered by major and minor groups.  The instructions within a        }
{ cluster all have the same bit field layout.  The enumeration values use the high order 7        }
{ bits of the relocation instruction.  Unused low order bits are set to zero.                    }
    kPEFRelocBySectDWithSkip    = $00;                            {  Binary: 00x_xxxx  }
    kPEFRelocBySectC            = $20;                            {  Binary: 010_0000, group is "RelocRun"  }
    kPEFRelocBySectD            = $21;                            {  Binary: 010_0001  }
    kPEFRelocTVector12            = $22;                            {  Binary: 010_0010  }
    kPEFRelocTVector8            = $23;                            {  Binary: 010_0011  }
    kPEFRelocVTable8            = $24;                            {  Binary: 010_0100  }
    kPEFRelocImportRun            = $25;                            {  Binary: 010_0101  }
    kPEFRelocSmByImport            = $30;                            {  Binary: 011_0000, group is "RelocSmIndex"  }
    kPEFRelocSmSetSectC            = $31;                            {  Binary: 011_0001  }
    kPEFRelocSmSetSectD            = $32;                            {  Binary: 011_0010  }
    kPEFRelocSmBySection        = $33;                            {  Binary: 011_0011  }
    kPEFRelocIncrPosition        = $40;                            {  Binary: 100_0xxx  }
    kPEFRelocSmRepeat            = $48;                            {  Binary: 100_1xxx  }
    kPEFRelocSetPosition        = $50;                            {  Binary: 101_000x  }
    kPEFRelocLgByImport            = $52;                            {  Binary: 101_001x  }
    kPEFRelocLgRepeat            = $58;                            {  Binary: 101_100x  }
    kPEFRelocLgSetOrBySection    = $5A;                            {  Binary: 101_101x  }
    kPEFRelocUndefinedOpcode    = $FF;                            {  Used in masking table for all undefined values.  }


{ ----------------------------------------------------------------------------    }
{ The RelocLgSetOrBySection instruction has an additional 4 bits of subopcode.    }
    kPEFRelocLgBySectionSubopcode = $00;                        {  Binary: 0000  }
    kPEFRelocLgSetSectCSubopcode = $01;                            {  Binary: 0001  }
    kPEFRelocLgSetSectDSubopcode = $02;                            {  Binary: 0010  }


{ ------------------------------------------------------------------------------------------    }
{ The initial values for the opcode "masking" table.  This has the enumeration values from        }
{ above with appropriate replications for "don't care" bits.  It is almost certainly shorter    }
{ and faster to look up the masked value in a table than to use a branch tree.                    }

{ =========================================================================================== }
{ RelocBySectDWithSkip Instruction }
{ -------------------------------- }

{ -------------------------------------------------------------------------------------------    }
{ The "RelocBySectDWithSkip" instruction has the following bit field layout.                    }
{                                                                                                 }
{                             1         1                                                        }
{         0 1 2             9 0         5                                                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                        }
{        |0 0| skip count    | rel count |                                                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                        }
{        | 2 |<-- 8 bits --->|<--  6 --->|                                                        }
{                                                                                                 }
{ ! Note that the stored skip count and reloc count are the actual values!                        }
    kPEFRelocWithSkipMaxSkipCount = 255;
    kPEFRelocWithSkipMaxRelocCount = 63;


{ =========================================================================================== }
{ RelocRun Group }
{ -------------- }

{ -------------------------------------------------------------------------------------------    }
{ The "RelocRun" group includes the "RelocBySectC", "RelocBySectD", "RelocTVector12",            }
{ "RelocTVector8", "RelocVTable8", and "RelocImportRun" instructions.  This group has the        }
{ following bit field layout.                                                                    }
{                                                                                                 }
{                                       1                                                        }
{         0   2 3     6 7               5                                                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                        }
{        |0 1 0| subop.| run length      |                                                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                        }
{        |  3  |<- 4 ->|<-- 9 bits ----->|                                                        }
{                                                                                                 }
{ ! Note that the stored run length is the actual value minus 1, but the macros deal with the    }
{ ! actual value!                                                                                }
    kPEFRelocRunMaxRunLength    = 512;


{ =========================================================================================== }
{ RelocSmIndex Group }
{ ------------------ }

{ ----------------------------------------------------------------------------------------    }
{ The "RelocSmIndex" group includes the "RelocSmByImport", "RelocSmSetSectC",                }
{ "RelocSmSetSectD" and "RelocSmBySection" instructions.  This group has the following bit    }
{ field layout.                                                                            }
{                                                                                             }
{                                       1                                                    }
{         0   2 3     6 7               5                                                    }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                    }
{        |0 1 1| subop.| index           |                                                    }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                    }
{        |  3  |<- 4 ->|<-- 9 bits ----->|                                                    }
{                                                                                             }
{ ! Note that the stored index is the actual value!                                        }
    kPEFRelocSmIndexMaxIndex    = 511;


{ =========================================================================================== }
{ RelocIncrPosition Instruction }
{ ----------------------------- }

{ -------------------------------------------------------------------------------------------    }
{ The "RelocIncrPosition" instruction has the following bit field layout.                        }
{                                                                                                 }
{                                       1                                                        }
{         0     3 4                     5                                                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                        }
{        |1 0 0 0| offset                |                                                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                        }
{        |<- 4 ->|<-- 12 bits ---------->|                                                        }
{                                                                                                 }
{ ! Note that the stored offset is the actual value minus 1, but the macros deal with the        }
{ ! actual value!                                                                                }
    kPEFRelocIncrPositionMaxOffset = 4096;


{ =========================================================================================== }
{ RelocSmRepeat Instruction }
{ ------------------------- }

{ -------------------------------------------------------------------------------------------    }
{ The "RelocSmRepeat" instruction has the following bit field layout.                            }
{                                                                                                 }
{                                       1                                                        }
{         0     3 4     7 8             5                                                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                        }
{        |1 0 0 1| chnks | repeat count  |                                                        }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                        }
{        |<- 4 ->|<- 4 ->|<-- 8 bits --->|                                                        }
{                                                                                                 }
{ ! Note that the stored chunk count and repeat count are the actual values minus 1, but the    }
{ ! macros deal with the actual values!                                                        }
    kPEFRelocSmRepeatMaxChunkCount = 16;
    kPEFRelocSmRepeatMaxRepeatCount = 256;


{ =========================================================================================== }
{ RelocSetPosition Instruction }
{ ---------------------------- }

{ -------------------------------------------------------------------------------------------    }
{ The "RelocSetPosition" instruction has the following bit field layout.                        }
{                                                                                                 }
{                                       1                                   1                    }
{         0         5 6                 5     0                             5                    }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                    }
{        |1 0 1 0 0 0| offset (high)     |   | offset (low)                  |                    }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                    }
{        |<-- 6 ---->|<-- 10 bits ------>|   |<-- 16 bits ------------------>|                    }
{                                                                                                 }
{ ! Note that the stored offset is the actual value!                                            }
    kPEFRelocSetPosMaxOffset    = $03FFFFFF;                    {  67,108,863  }


{ =========================================================================================== }
{ RelocLgByImport Instruction }
{ --------------------------- }

{ -------------------------------------------------------------------------------------------    }
{ The "RelocLgByImport" instruction has the following bit field layout.                        }
{                                                                                                 }
{                                       1                                   1                    }
{         0         5 6                 5     0                             5                    }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                    }
{        |1 0 1 0 0 1| index (high)      |   | index (low)                   |                    }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                    }
{        |<-- 6 ---->|<-- 10 bits ------>|   |<-- 16 bits ------------------>|                    }
{                                                                                                 }
{ ! Note that the stored offset is the actual value!                                            }
    kPEFRelocLgByImportMaxIndex    = $03FFFFFF;                    {  67,108,863  }


{ =========================================================================================== }
{ RelocLgRepeat Instruction }
{ ------------------------- }

{ -------------------------------------------------------------------------------------------    }
{ The "RelocLgRepeat" instruction has the following bit field layout.                            }
{                                                                                                 }
{                             1         1                                   1                    }
{         0         5 6     9 0         5     0                             5                    }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                    }
{        |1 0 1 1 0 0| chnks | rpt (high)|   | repeat count (low)            |                    }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                    }
{        |<--  6 --->|<- 4 ->|<--  6 --->|   |<-- 16 bits ------------------>|                    }
{                                                                                                 }
{ ! Note that the stored chunk count is the actual value minus 1, but the macros deal with        }
{ ! the actual value!  The stored repeat count is the actual value!                            }
    kPEFRelocLgRepeatMaxChunkCount = 16;
    kPEFRelocLgRepeatMaxRepeatCount = $003FFFFF;                {  4,194,303  }


{ =========================================================================================== }
{ RelocLgSetOrBySection Group }
{ --------------------------- }

{ -------------------------------------------------------------------------------------------    }
{ The "RelocLgSetOrBySection" instruction is really a group including the "RelocLgBySection",    }
{ "RelocLgSetSectC" and "RelocLgSetSectD" instructions.  This group has the following bit        }
{ field layout.                                                                                }
{                                                                                                 }
{                             1         1                                   1                    }
{         0         5 6     9 0         5     0                             5                    }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                    }
{        |1 0 1 1 0 1| subop | idx (high)|   | index (low)                   |                    }
{        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                    }
{        |<--  6 --->|<- 4 ->|<--  6 --->|   |<-- 16 bits ------------------>|                    }
{                                                                                                 }
{ ! Note that the stored index is the actual value!                                            }
    kPEFRelocLgSetOrBySectionMaxIndex = $003FFFFF;                {  4,194,303  }



{$ALIGN RESET}
{$POP}

{$SETC UsingIncludes := PEFBinaryFormatIncludes}

{$ENDC} {__PEFBINARYFORMAT__}

{$IFC NOT UsingIncludes}
 END.
{$ENDC}