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diff --git a/exefmt.txt b/exefmt.txt deleted file mode 100644 index 51fa9a7..0000000 --- a/exefmt.txt +++ /dev/null @@ -1,593 +0,0 @@ -INF: Executable-File Header Format [P_WinSDK] - -3.00 -WINDOWS -PSSONLY | Windows 3 Developers Notes softlib ENDUSER - -Summary: - -Note: This article is part of a set of seven articles, collectively -called the "Windows 3.00 Developer's Notes." More information about -the contents of the other articles, and procedures for ordering a -hard-copy set, can be found in the knowledge base article titled "INF: -The Windows 3.00 Developer's Notes" (Q65260). - -This article can be found in the Software/Data Library by searching on -the word EXEFMT or S12688. EXEFMT was archived using the PKware -file-compression utility. - -More Information: - -Microsoft defined the segmented executable file format for Windows -applications and dynamic-link libraries (DLLs). This file format is -also referred to as the New Executable Format. This new format is an -extension of the existing MS-DOS .EXE format (old-style format). The -purpose of the segmented executable format is to provide the -information needed to support the dynamic linking and segmentation -capabilities of the Windows environment. - -An executable file contains Microsoft Windows code and data, or -Windows code, data, and resources. Specific fields have been added to -the old-style .EXE format header to indicate the existence of the -segmented file format. The old-style header may contain a valid -executable program, called a stub program, that will be executed if -the program is run on MS-DOS (without Windows). This stub program -usually prints a message indicating that Microsoft Windows is required -to run the program. The segmented executable format extensions also -begin with a header that describes the contents and location of the -executable image in the file. The loader uses this header information -when it loads the executable segments in memory. - - -====================================================================== - OLD-STYLE HEADER EXTENSIONS -====================================================================== - -The old-style header contains information the loader expects for a DOS -executable file. It describes a stub program (WINSTUB) the loader can -place in memory when necessary, it points to the new-style header, and -it contains the stub programs relocation table. - -The following illustrates the distinct parts of the old-style -executable format: - - +-------------------------+ - 00h | Old-style header info | - +-------------------------+ - 20h | Reserved | - +-------------------------+ - 3Ch | Offset to segmented | - | .EXE header | - +-------------------------+ - 40h | Relocation table and | - | DOS stub program | - +-------------------------+ - | Segmented .EXE Header | - | . | - | . | - | . | - -The word at offset 18h in the old-style .EXE header contains the -relative byte offset to the stub program's relocation table. If this -offset is 40h, then the double word at offset 3Ch is assumed to be the -relative byte offset from the beginning of the file to the beginning -of the segmented executable header. A new-format .EXE file is -identified if the segmented executable header contains a valid -signature. If the signature is not valid, the file is assumed to be an -old-style format .EXE file. The remainder of the old-style format -header will describe a DOS program, the stub. The stub may be any -valid program but will typically be a program that displays an error -message. - -====================================================================== - SEGMENTED EXE FORMAT -====================================================================== - -Because Windows executable files are often larger than one segment -(64K), additional information (that does not appear in the old-style -header) is required so that the loader can load each segment properly. -The segmented EXE format was developed to provide the loader with this -information. - -The segmented .EXE file has the following format: - - +-----------------+ - 00h | Old-style EXE | - | Header | - +-----------------+ - 20h | Reserved | - +-----------------+ - 3Ch | Offset to | ---+ - | Segmented Header| | - +-----------------+ | - 40h | Relocation Table| | - | & Stub Program | | - +-----------------+ | - | | | - +-----------------+ | - xxh | Segmented EXE | <--+ - | Header | - +-----------------+ - | Segment Table | - +-----------------+ - | Resource Table | - +-----------------+ - | Resident Name | - | Table | - +-----------------+ - | Module Reference| - | Table | - +-----------------+ - | Imported Names | - | Table | - +-----------------+ - | Entry Table | - +-----------------+ - | Non-Resident | - | Name Table | - +-----------------+ - | Seg #1 Data | - | Seg #1 Info | - +-----------------+ - . - . - . - +-----------------+ - | Seg #n Data | - | Seg #n Info | - +-----------------+ - - -The following sections describe each of the components that make up -the segmented EXE format. Each section contains a description of the -component and the fields in the structures that make up that -component. - -Note: All unused fields and flag bits are reserved for future use and -must contain 0 (zero) values. - -====================================================================== - SEGMENTED EXE HEADER -====================================================================== - -The segmented EXE header contains general information about the EXE -file and contains information on the location and size of the other -sections. The Windows loader copies this section, along with other -data, into the module table in the system data. The module table is -internal data used by the loader to manage the loaded executable -modules in the system and to support dynamic linking. - -The following describes the format of the segmented executable header. -For each field, the offset is given relative to the beginning of the -segmented header, the size of the field is defined, and a description -is given. - - Offset Size Description - ------ ---- ----------- - - 00h DW Signature word. - "N" is low-order byte. - "E" is high-order byte. - - 02h DB Version number of the linker. - - 03h DB Revision number of the linker. - - 04h DW Entry Table file offset, relative to the beginning of - the segmented EXE header. - 06h DW Number of bytes in the entry table. - - 08h DD 32-bit CRC of entire contents of file. - These words are taken as 00 during the calculation. - - 0Ch DW Flag word. - 0000h = NOAUTODATA - 0001h = SINGLEDATA (Shared automatic data segment) - 0002h = MULTIPLEDATA (Instanced automatic data - segment) - 2000h = Errors detected at link time, module will not - load. - 8000h = Library module. - The SS:SP information is invalid, CS:IP points - to an initialization procedure that is called - with AX equal to the module handle. This - initialization procedure must perform a far - return to the caller, with AX not equal to - zero to indicate success, or AX equal to zero - to indicate failure to initialize. DS is set - to the library's data segment if the - SINGLEDATA flag is set. Otherwise, DS is set - to the caller's data segment. - - A program or DLL can only contain dynamic - links to executable files that have this - library module flag set. One program cannot - dynamic-link to another program. - - 0Eh DW Segment number of automatic data segment. - This value is set to zero if SINGLEDATA and - MULTIPLEDATA flag bits are clear, NOAUTODATA is - indicated in the flags word. - - A Segment number is an index into the module's segment - table. The first entry in the segment table is segment - number 1. - - 10h DW Initial size, in bytes, of dynamic heap added to the - data segment. This value is zero if no initial local - heap is allocated. - - 12h DW Initial size, in bytes, of stack added to the data - segment. This value is zero to indicate no initial - stack allocation, or when SS is not equal to DS. - - 14h DD Segment number:offset of CS:IP. - - 18h DD Segment number:offset of SS:SP. - If SS equals the automatic data segment and SP equals - zero, the stack pointer is set to the top of the - automatic data segment just below the additional heap - area. - - +--------------------------+ - | additional dynamic heap | - +--------------------------+ <- SP - | additional stack | - +--------------------------+ - | loaded auto data segment | - +--------------------------+ <- DS, SS - - 1Ch DW Number of entries in the Segment Table. - - 1Eh DW Number of entries in the Module Reference Table. - 20h DW Number of bytes in the Non-Resident Name Table. - - 22h DW Segment Table file offset, relative to the beginning - of the segmented EXE header. - - 24h DW Resource Table file offset, relative to the beginning - of the segmented EXE header. - - 26h DW Resident Name Table file offset, relative to the - beginning of the segmented EXE header. - - 28h DW Module Reference Table file offset, relative to the - beginning of the segmented EXE header. - - 2Ah DW Imported Names Table file offset, relative to the - beginning of the segmented EXE header. - - 2Ch DD Non-Resident Name Table offset, relative to the - beginning of the file. - - 30h DW Number of movable entries in the Entry Table. - - 32h DW Logical sector alignment shift count, log(base 2) of - the segment sector size (default 9). - - 34h DW Number of resource entries. - - 36h DB Executable type, used by loader. - 02h = WINDOWS - - 37h-3Fh DB Reserved, currently 0's. - - -====================================================================== - SEGMENT TABLE -====================================================================== - -The segment table contains an entry for each segment in the executable -file. The number of segment table entries are defined in the segmented -EXE header. The first entry in the segment table is segment number 1. -The following is the structure of a segment table entry. - - Size Description - ---- ----------- - - DW Logical-sector offset (n byte) to the contents of the segment - data, relative to the beginning of the file. Zero means no - file data. - - DW Length of the segment in the file, in bytes. Zero means 64K. - - DW Flag word. - 0007h = TYPE_MASK Segment-type field. - 0000h = CODE Code-segment type. - 0001h = DATA Data-segment type. - 0010h = MOVEABLE Segment is not fixed. - 0040h = PRELOAD Segment will be preloaded; read-only if - this is a data segment. - 0100h = RELOCINFO Set if segment has relocation records. - F000h = DISCARD Discard priority. - - DW Minimum allocation size of the segment, in bytes. Total size - of the segment. Zero means 64K. - - -====================================================================== - RESOURCE TABLE -====================================================================== - -The resource table follows the segment table and contains entries for -each resource in the executable file. The resource table consists of -an alignment shift count, followed by a table of resource records. The -resource records define the type ID for a set of resources. Each -resource record contains a table of resource entries of the defined -type. The resource entry defines the resource ID or name ID for the -resource. It also defines the location and size of the resource. The -following describes the contents of each of these structures: - - Size Description - ---- ----------- - - DW Alignment shift count for resource data. - - A table of resource type information blocks follows. The following - is the format of each type information block: - - DW Type ID. This is an integer type if the high-order bit is - set (8000h); otherwise, it is an offset to the type string, - the offset is relative to the beginning of the resource - table. A zero type ID marks the end of the resource type - information blocks. - - DW Number of resources for this type. - - DD Reserved. - - A table of resources for this type follows. The following is - the format of each resource (8 bytes each): - - DW File offset to the contents of the resource data, - relative to beginning of file. The offset is in terms - of the alignment shift count value specified at - beginning of the resource table. - - DW Length of the resource in the file (in bytes). - - DW Flag word. - 0010h = MOVEABLE Resource is not fixed. - 0020h = PURE Resource can be shared. - 0040h = PRELOAD Resource is preloaded. - - DW Resource ID. This is an integer type if the high-order - bit is set (8000h), otherwise it is the offset to the - resource string, the offset is relative to the - beginning of the resource table. - - DD Reserved. - - Resource type and name strings are stored at the end of the - resource table. Note that these strings are NOT null terminated and - are case sensitive. - - DB Length of the type or name string that follows. A zero value - indicates the end of the resource type and name string, also - the end of the resource table. - - DB ASCII text of the type or name string. - - -====================================================================== - RESIDENT-NAME TABLE -====================================================================== - -The resident-name table follows the resource table, and contains this -module's name string and resident exported procedure name strings. The -first string in this table is this module's name. These name strings -are case-sensitive and are not null-terminated. The following -describes the format of the name strings: - - Size Description - ---- ----------- - - DB Length of the name string that follows. A zero value indicates - the end of the name table. - - DB ASCII text of the name string. - - DW Ordinal number (index into entry table). This value is ignored - for the module name. - - -====================================================================== - MODULE-REFERENCE TABLE -====================================================================== - -The module-reference table follows the resident-name table. Each entry -contains an offset for the module-name string within the imported- -names table; each entry is 2 bytes long. - - Size Description - ---- ----------- - - DW Offset within Imported Names Table to referenced module name - string. - - -====================================================================== - IMPORTED-NAME TABLE -====================================================================== - -The imported-name table follows the module-reference table. This table -contains the names of modules and procedures that are imported by the -executable file. Each entry is composed of a 1-byte field that -contains the length of the string, followed by any number of -characters. The strings are not null-terminated and are case -sensitive. - - Size Description - ---- ----------- - - DB Length of the name string that follows. - - DB ASCII text of the name string. - - -====================================================================== - ENTRY TABLE -====================================================================== - -The entry table follows the imported-name table. This table contains -bundles of entry-point definitions. Bundling is done to save space in -the entry table. The entry table is accessed by an ordinal value. -Ordinal number one is defined to index the first entry in the entry -table. To find an entry point, the bundles are scanned searching for a -specific entry point using an ordinal number. The ordinal number is -adjusted as each bundle is checked. When the bundle that contains the -entry point is found, the ordinal number is multiplied by the size of -the bundle's entries to index the proper entry. - -The linker forms bundles in the most dense manner it can, under the -restriction that it cannot reorder entry points to improve bundling. -The reason for this restriction is that other .EXE files may refer to -entry points within this bundle by their ordinal number. The following -describes the format of the entry table bundles. - - Size Description - ---- ----------- - - DB Number of entries in this bundle. All records in one bundle - are either moveable or refer to the same fixed segment. A zero - value in this field indicates the end of the entry table. - - DB Segment indicator for this bundle. This defines the type of - entry table entry data within the bundle. There are three - types of entries that are defined. - - 000h = Unused entries. There is no entry data in an unused - bundle. The next bundle follows this field. This is - used by the linker to skip ordinal numbers. - - 001h-0FEh = Segment number for fixed segment entries. A fixed - segment entry is 3 bytes long and has the following - format. - - DB Flag word. - 01h = Set if the entry is exported. - 02h = Set if the entry uses a global (shared) data - segments. - The first assembly-language instruction in the - entry point prologue must be "MOV AX,data - segment number". This may be set only for - SINGLEDATA library modules. - - DW Offset within segment to entry point. - - 0FFH = Moveable segment entries. The entry data contains the - segment number for the entry points. A moveable segment - entry is 6 bytes long and has the following format. - - DB Flag word. - 01h = Set if the entry is exported. - 02h = Set if the entry uses a global (shared) data - segments. - - INT 3FH. - - DB Segment number. - - DW Offset within segment to entry point. - - -====================================================================== - NONRESIDENT-NAME TABLE -====================================================================== - -The nonresident-name table follows the entry table, and contains a -module description and nonresident exported procedure name strings. -The first string in this table is a module description. These name -strings are case-sensitive and are not null-terminated. The name -strings follow the same format as those defined in the resident name -table. - - -====================================================================== - PER SEGMENT DATA -====================================================================== - -The location and size of the per-segment data is defined in the -segment table entry for the segment. If the segment has relocation -fixups, as defined in the segment table entry flags, they directly -follow the segment data in the file. The relocation fixup information -is defined as follows: - - - Size Description - ---- ----------- - - DW Number of relocation records that follow. - - A table of relocation records follows. The following is the format - of each relocation record. - - DB Source type. - 0Fh = SOURCE_MASK - 00h = LOBYTE - 02h = SEGMENT - 03h = FAR_ADDR (32-bit pointer) - 05h = OFFSET (16-bit offset) - - DB Flags byte. - 03h = TARGET_MASK - 00h = INTERNALREF - 01h = IMPORTORDINAL - 02h = IMPORTNAME - 03h = OSFIXUP - 04h = ADDITIVE - - DW Offset within this segment of the source chain. - If the ADDITIVE flag is set, then target value is added to - the source contents, instead of replacing the source and - following the chain. The source chain is an 0FFFFh - terminated linked list within this segment of all - references to the target. - - The target value has four types that are defined in the flag - byte field. The following are the formats for each target - type: - - INTERNALREF - - DB Segment number for a fixed segment, or 0FFh for a - movable segment. - - DB 0 - - DW Offset into segment if fixed segment, or ordinal - number index into Entry Table if movable segment. - - IMPORTNAME - - DW Index into module reference table for the imported - module. - - DW Offset within Imported Names Table to procedure name - string. - - IMPORTORDINAL - - DW Index into module reference table for the imported - module. - DW Procedure ordinal number. - - OSFIXUP - - DW Operating system fixup type. - Floating-point fixups. - 0001h = FIARQQ, FJARQQ - 0002h = FISRQQ, FJSRQQ - 0003h = FICRQQ, FJCRQQ - 0004h = FIERQQ - 0005h = FIDRQQ - 0006h = FIWRQQ - - DW 0 - -====================================================================== - -Microsoft is a registered trademark and Windows is a trademark of -Microsoft Corporation. - -Additional reference words: 3.0 |