MZ .EXE format for MS-DOS. More...

#include <mzexe.h>

Inheritance diagram for Microsoft::MZFormat:

Classes
struct	PIF
	Concurrent DOS embedded program information, produced by PIFED. More...

struct	Relocation
	Represents a relocation entry in the header, as a pair of 16-bit words. More...

Public Types
enum	magic_type { MAGIC_MZ = 1 , MAGIC_ZM , MAGIC_DL }
	Type of magic number, usually "MZ". More...

enum	memory_model_t { MODEL_DEFAULT , MODEL_TINY , MODEL_SMALL , MODEL_COMPACT , MODEL_LARGE }
	Represents the memory model of the running executable, which is the way in which the segments are set up during execution. More...

Public Member Functions
uint32_t	GetFileSize () const

magic_type	GetSignature () const

void	SetSignature (magic_type magic)

void	Clear () override
	Resets all fields to their default values, deallocate memory.

void	SetFileSize (uint32_t size)

uint32_t	GetHeaderSize ()

uint32_t	GetPifOffset () const

void	ReadFile (Linker::Reader &rd) override
	Loads file into memory.

void	WriteFile (Linker::Writer &wr) override
	Stores data in memory to file.

void	Dump (Dumper::Dumper &dump) override
	Display file contents in a nice manner.

void	CalculateValues () override
	Intermediate step between processing module and generating output file to set up headers and management sections It is expected that after a module is processed, additional steps are required to evaluate the final values of the fields.

bool	FormatSupportsSegmentation () const override
	Whether the format supports multiple segments.

bool	FormatIs16bit () const override
	Whether the format is 16-bit or not.

unsigned	FormatAdditionalSectionFlags (std::string section_name) const override

void	SetModel (std::string model) override
	Sets the way memory is organized, typically modifying a built-in script.

void	SetOptions (std::map< std::string, std::string > &options) override
	Passes command line parameters as settings over to format object.

void	OnNewSegment (std::shared_ptr< Linker::Segment > segment) override
	Callback function when allocating a new segment When the linker script runs, it creates segments consecutively. Overriding this method permits the output format to handle the allocated segment.

void	CreateDefaultSegments ()
	Create the required segments, if they have not already been allocated. The MZ format uses a single segment.

std::unique_ptr< Script::List >	GetScript (Linker::Module &module)

void	Link (Linker::Module &module)
	Link application according to script or memory model ()

void	ProcessModule (Linker::Module &module) override
	Processes the module object and initializes format fields.

uint32_t	GetDataSize () const

void	GenerateFile (std::string filename, Linker::Module &module) override
	The main function that handles processing, calculating and generating the final image.

std::string	GetDefaultExtension (Linker::Module &module, std::string filename) override
	Appends a default extension to the filename.

Public Member Functions inherited from Linker::OutputFormat
virtual bool	AddSupplementaryOutputFormat (std::string subformat)
	If the output format actually drives multiple output formats (resource file, apple double, etc.), specify multiple types, return false if unknown.

std::optional< std::string >	FetchOption (std::map< std::string, std::string > &options, std::string name)
	Convenience method to look up option by name.

std::string	FetchOption (std::map< std::string, std::string > &options, std::string name, std::string default_value)
	Convenience method to look up option by name, returning default value if name is missing.

std::optional< offset_t >	FetchIntegerOption (std::map< std::string, std::string > &options, std::string name)
	Convenience method to look up option by name and convert it to integer.

virtual void	SetLinkScript (std::string script_file, std::map< std::string, std::string > &options)
	Selects a script file to use for linking.

virtual std::string	GetDefaultExtension (Linker::Module &module)
	Provides a default filename for the output file.

virtual bool	FormatIsLinear () const
	Whether the address space is linear or segmented.

virtual bool	FormatSupportsResources () const
	Whether the format supports resources.

virtual bool	FormatSupportsLibraries () const
	Whether the format supports libraries.

Public Member Functions inherited from Linker::Format
	Format (offset_t file_offset=0)

Public Member Functions inherited from Linker::LinkerManager
void	ClearLinkerManager ()

void	SetLinkScript (std::string script_file, std::map< std::string, std::string > &options)
	Sets up the linker script and linker parameters.

bool	SetLinkerParameter (std::map< std::string, std::string > &options, std::string key)
	Sets a single linker parameter, if inside options.

bool	SetLinkerParameter (std::map< std::string, std::string > &options, std::string key, std::string variable)
	Sets a single linker parameter, if inside options.

std::unique_ptr< Script::List >	GetScript (Linker::Module &module)
	Compiles the linker script into an internal format.

offset_t	GetCurrentAddress () const
	Retrieves current address pointer.

void	SetCurrentAddress (offset_t address)
	Moves the current address pointer further, and if the current segment already contains data, fill it up to the point.

void	AlignCurrentAddress (offset_t align)
	Aligns current address to alignment, using SetCurrentAddress.

void	SetLatestBase (offset_t address)
	Sets the base of the current section (the value from which offsets are counted from)

void	FinishCurrentSegment ()
	Closes the current segment, sets current_segment to null.

std::shared_ptr< Segment >	AppendSegment (std::string name)
	Terminates the current segment (if there is one), creates a new segment and attaches it to the image.

std::shared_ptr< Segment >	FetchSegment (std::string name)
	Attempts to fetch a segment, returns null if not found.

void	AppendSection (std::shared_ptr< Section > section)
	Adds a new section to the current segment, sets the base to the same as the segment.

void	ProcessScript (std::unique_ptr< Script::List > &directives, Module &module)
	Executes a parsed linker script on a module and collects segments The function OnNewSegment can be defined to handle each newly allocated segment.

void	ProcessAction (std::unique_ptr< Script::Node > &action, Module &module)

void	PostProcessAction (std::unique_ptr< Script::Node > &action, Module &module)

void	ProcessCommand (std::unique_ptr< Script::Node > &command, Module &module)

bool	CheckPredicate (std::unique_ptr< Script::Node > &predicate, std::shared_ptr< Section > section, Module &module)

offset_t	EvaluateExpression (std::unique_ptr< Script::Node > &expression, Module &module)

Public Attributes
char	signature [2] = { 'M', 'Z' }
	The magic number at the start of the executable file, usually "MZ".

uint16_t	last_block_size = 0
	Size of last 512 byte block, 0 if full. Set by CalculateValues.

uint16_t	file_size_blocks = 0
	Size of MZ image in 512 blocks, rounded up. Set by CalculateValues.

uint16_t	relocation_count = 0
	Number of relocations. Updated by CalculateValues.

uint16_t	header_size_paras = 0
	Size of MZ header. Updated by CalculateValues.

uint16_t	min_extra_paras = 0
	Minimum required extra memory, in paragraphs.

uint16_t	max_extra_paras = 0
	Maximum required extra memory, in paragraphs. Set by CalculateValues using extra_paras.

uint16_t	ss = 0
	Initial value for the stack segment (SS)

uint16_t	sp = 0
	Initial value for the stack (SP)

uint16_t	checksum = 0
	Checksum.

uint16_t	ip = 0
	Entry point initial value for IP.

uint16_t	cs = 0
	Initial value for the code segment (CS)

uint16_t	relocation_offset = 0
	Offset to first relocation. Updated by CalculateValues.

uint16_t	overlay_number = 0
	Overlay number, should be 0 for main programs, not used for .exm files.

uint16_t	data_segment = 0
	Starting paragraph of program data, only required for .exm files.

std::vector< Relocation >	relocations
	Address relocation offsets to paragraph fixups.

std::unique_ptr< PIF >	pif
	Concurrent DOS program information entry, allocated only if present.

std::shared_ptr< Linker::Writable >	image
	The program image, placed after the MZ header.

memory_model_t	memory_model = MODEL_DEFAULT
	Memory model of generated executable.

uint16_t	extra_paras = 0
	Required maximum extra paragraphs after bss.

uint32_t	zero_fill = 0
	Total size of bss and stack.

uint32_t	option_header_align = 0x10
	User provided alignment value for header size.

uint32_t	option_file_align = 1
	User provided alignment value for file align.

Public Attributes inherited from Linker::Format
offset_t	file_offset

Public Attributes inherited from Linker::LinkerManager
offset_t	current_base = 0
	The base address of the current section.

std::vector< std::shared_ptr< Segment > >	segment_vector
	Ordered sequence of segments.

std::map< std::string, std::shared_ptr< Segment > >	segment_map
	Map of segments from their names.

std::shared_ptr< Segment >	current_segment
	Currently processed segment.

std::map< std::string, Location >	linker_parameters
	Parameters that permit customizing the linker script.

std::string	linker_script
	Contents of the linker script.

Additional Inherited Members
Protected Attributes inherited from Linker::LinkerManager
offset_t	current_address = 0
	Holds the current address value when there is no current_segment.

bool	current_is_template = false

bool	current_is_template_head = false

offset_t	template_counter = 0

std::string	current_template_name

Detailed Description

MZ .EXE format for MS-DOS.

The native .exe file format for MS-DOS, developed as an upgrade from the earlier flat binary .com file format. They are named after their identification code "MZ" that appears as the first two bytes of executables.

HP 100LX/200LX System Manager modules (file extension .exm) use a variant of this format, with "MZ" replaced with "DL", executable and non-executable parts separated into separate segments, and the field at offset 0x1A storing the segment of the data segment.

First appeared probably around MS-DOS 1.0 (they were absent from PC DOS 0.9), they were initially identified by the new file extension ".exe". Since MS-DOS 2.0, MZ executables may also have the extension ".com", as DOS only looks at the first two bytes to determine the file format.

Member Enumeration Documentation

◆ magic_type

enum Microsoft::MZFormat::magic_type

Type of magic number, usually "MZ".

Enumerator
MAGIC_MZ	The most common magic number "MZ".
MAGIC_ZM	According to some sources such as Ralf Brown's interrupt list, some early excutables started with the sequence "ZM" instead.
MAGIC_DL	HP 100LX/200LX System Manager modules (.exm) use the magic number "DL".

◆ memory_model_t

enum Microsoft::MZFormat::memory_model_t

Represents the memory model of the running executable, which is the way in which the segments are set up during execution.

Enumerator
MODEL_DEFAULT	Default model, same as small.
MODEL_TINY	Tiny model, code and data segment are the same.
MODEL_SMALL	Small model, separate code and data segments.
MODEL_COMPACT	Compact model, separate code and multiple data segments.
MODEL_LARGE	Large model, every section is a separate segment.

Member Function Documentation

◆ CalculateValues()

void MZFormat::CalculateValues ( )

overridevirtual

Intermediate step between processing module and generating output file to set up headers and management sections It is expected that after a module is processed, additional steps are required to evaluate the final values of the fields.

Reimplemented from Linker::OutputFormat.

◆ Clear()

void MZFormat::Clear ( )

overridevirtual

Resets all fields to their default values, deallocate memory.

Reimplemented from Linker::Format.

◆ Dump()

void MZFormat::Dump ( Dumper::Dumper & dump )

overridevirtual

Display file contents in a nice manner.

Reimplemented from Linker::Format.

◆ FormatAdditionalSectionFlags()

unsigned MZFormat::FormatAdditionalSectionFlags ( std::string section_name ) const

overridevirtual

Reimplemented from Linker::OutputFormat.

◆ FormatIs16bit()

bool MZFormat::FormatIs16bit ( ) const

overridevirtual

Whether the format is 16-bit or not.

This is needed for the ELF parser which can not distinguish between the 8086 and 80386 backends.

Reimplemented from Linker::OutputFormat.

◆ FormatSupportsSegmentation()

bool MZFormat::FormatSupportsSegmentation ( ) const

overridevirtual

Whether the format supports multiple segments.

This is typically true for Intel 8086 targets and false for non-Intel targets. The ELF parser uses this to provide extended relocations, including the following:

$$SEG$<section name>
$$SEGOF$<symbol name>
$$SEGAT$<symbol name>
$$WRTSEG$<symbol name>$<section name>
$$SEGDIF$<section name>$<section name>

Reimplemented from Linker::OutputFormat.

◆ GenerateFile()

void MZFormat::GenerateFile	(	std::string	filename,
		Linker::Module &	module )

overridevirtual

The main function that handles processing, calculating and generating the final image.

Reimplemented from Linker::OutputFormat.

◆ GetDefaultExtension()

std::string MZFormat::GetDefaultExtension	(	Linker::Module &	module,
		std::string	filename )

overridevirtual

Appends a default extension to the filename.

A typical behavior would be to append .exe at the end of the filename. The default action is to leave it intact.

Reimplemented from Linker::OutputFormat.

◆ OnNewSegment()

void MZFormat::OnNewSegment ( std::shared_ptr< Linker::Segment > segment )

overridevirtual

Callback function when allocating a new segment When the linker script runs, it creates segments consecutively. Overriding this method permits the output format to handle the allocated segment.

Reimplemented from Linker::LinkerManager.

◆ ProcessModule()

void MZFormat::ProcessModule ( Linker::Module & object )

overridevirtual

Processes the module object and initializes format fields.

Reimplemented from Linker::OutputFormat.

◆ ReadFile()

void MZFormat::ReadFile ( Linker::Reader & in )

overridevirtual

Loads file into memory.

Implements Linker::Format.

◆ SetModel()

void MZFormat::SetModel ( std::string model )

overridevirtual

Sets the way memory is organized, typically modifying a built-in script.

Reimplemented from Linker::OutputFormat.

◆ SetOptions()

void MZFormat::SetOptions ( std::map< std::string, std::string > & options )

overridevirtual

Passes command line parameters as settings over to format object.

Reimplemented from Linker::OutputFormat.

◆ WriteFile()

void MZFormat::WriteFile ( Linker::Writer & out )

overridevirtual

Stores data in memory to file.

Implements Linker::Format.

The documentation for this class was generated from the following files:

src/format/mzexe.h
src/format/mzexe.cc

Classes

Public Types

Public Member Functions

Public Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ magic_type

◆ memory_model_t

Member Function Documentation

◆ CalculateValues()

◆ Clear()

◆ Dump()

◆ FormatAdditionalSectionFlags()

◆ FormatIs16bit()

◆ FormatSupportsSegmentation()

◆ GenerateFile()

◆ GetDefaultExtension()

◆ OnNewSegment()

◆ ProcessModule()

◆ ReadFile()

◆ SetModel()

◆ SetOptions()

◆ WriteFile()