PCOS::CMDFormat Class Reference

Olivetti M20 PCOS cmd/sav executable file format. More...

#include <pcos.h>

Inheritance diagram for PCOS::CMDFormat:

Classes
class	LoadBlock
class	MemoryBlock
	Represents a block of data in the file, also an end-of-block object is an instance of this type. More...
class	RelocationBlock
	A block containing a sequence of relocations between two blocks, either the offset or segment parts. More...
class	UnknownBlock
	Represents the contents of a block whose format is not known or implemented. More...

Public Types
enum	file_type : uint8_t { TYPE_CMD = 1 , TYPE_SAV = 9 }
	Executable types. More...

Public Member Functions
	CMDFormat (int type=TYPE_CMD)
void	ReadFile (Linker::Reader &rd) override
	Loads file into memory.
offset_t	WriteFile (Linker::Writer &wr) const override
	Stores data in memory to file.
void	Dump (Dumper::Dumper &dump) const 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.
std::string	GetDefaultExtension (Linker::Module &module, std::string filename) const override
	Appends a default extension to the filename.
const LoadBlock *	GetLoadBlockById (uint32_t block_id) const
LoadBlock *	GetLoadBlockById (uint32_t block_id)
Public Member Functions inherited from Linker::SegmentManager
void	ClearSegmentManager ()
void	SetLinkScript (std::string script_file, std::map< std::string, std::string > &options) override
	Sets up the linker script and linker parameters.
std::unique_ptr< Script::List >	GetScript (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.
virtual void	OnNewSegment (std::shared_ptr< Segment > segment)
	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.
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 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.
virtual void	SetOptions (std::map< std::string, std::string > &options)
	Passes command line parameters as settings over to format object.
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	SetModel (std::string model)
	Sets the way memory is organized, typically modifying a built-in script.
virtual void	ProcessModule (Module &object)
	Processes the module object and initializes format fields.
virtual void	GenerateFile (std::string filename, Module &module)
	The main function that handles processing, calculating and generating the final image.
virtual std::string	GetDefaultExtension (Module &module) const
	Provides a default filename for the output file.
virtual bool	FormatSupportsSegmentation () const
	Whether the format supports multiple segments.
virtual bool	FormatIs16bit () const
	Whether the format is 16-bit or not.
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.
virtual unsigned	FormatAdditionalSectionFlags (std::string section_name) const
Public Member Functions inherited from Linker::Format
	Format (offset_t file_offset=0)
virtual void	Clear ()
	Resets all fields to their default values, deallocate memory.
offset_t	ImageSize () const override
	Retrieves size of stored data.
offset_t	WriteFile (Writer &wr, offset_t count, offset_t offset=0) const override
	Writes data of non-zero filled sections.
Public Member Functions inherited from Linker::Image
virtual std::shared_ptr< const ActualImage >	AsImage () const
	Retrieves a randomly accessible image.
std::shared_ptr< ActualImage >	AsImage ()
	Retrieves a randomly accessible image.

Public Attributes
uint16_t	file_header_size = 0x40
	Size of header, following the first 3 bytes.
std::array< char, 6 >	linker_version
	String field following the first 7 bytes.
file_type	type = TYPE_CMD
	Type of executable.
uint32_t	entry_point
	24-bit entry point, memory block and offset
uint16_t	stack_size
	Size of stack.
uint16_t	allocation_length
std::vector< std::unique_ptr< MemoryBlock > >	blocks
	Sequence of blocks to be loaded.
Public Attributes inherited from Linker::SegmentManager
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.
Public Attributes inherited from Linker::Format
offset_t	file_offset

Additional Inherited Members
Protected Attributes inherited from Linker::SegmentManager
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

Olivetti M20 PCOS cmd/sav executable file format.

The native executable file format for the Olivetti M20 PCOS operating system, at least version 4. Earlier versions seem to use a different format. The PCOS also has a separate file format for abs executables. This is based on Christian Groessler's work.

Member Enumeration Documentation

file_type

enum PCOS::CMDFormat::file_type : uint8_t

Executable types.

Enumerator
TYPE_CMD	Executable which gets unloaded after execution.
TYPE_SAV	Executable that is kept resident in memory.

Member Function Documentation

CalculateValues()

void CMDFormat::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.

Dump()

void CMDFormat::Dump ( Dumper::Dumper & dump ) const

overridevirtual

Display file contents in a nice manner.

Reimplemented from Linker::Format.

GetDefaultExtension()

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

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.

ReadFile()

void CMDFormat::ReadFile ( Linker::Reader & rd )

overridevirtual

Loads file into memory.

Implements Linker::Format.

WriteFile()

offset_t CMDFormat::WriteFile ( Linker::Writer & wr ) const

overridevirtual

Stores data in memory to file.

Implements Linker::Format.

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

• src/format/pcos.h
• src/format/pcos.cc