rtl.h File Reference

RTEMS Run-Time Linker. More...

#include <link.h>
#include <rtems/chain.h>
#include <rtems/thread.h>
#include <rtems/rtl/rtl-allocator.h>
#include <rtems/rtl/rtl-archive.h>
#include <rtems/rtl/rtl-fwd.h>
#include <rtems/rtl/rtl-obj.h>
#include <rtems/rtl/rtl-obj-cache.h>
#include <rtems/rtl/rtl-obj-comp.h>
#include <rtems/rtl/rtl-sym.h>
#include <rtems/rtl/rtl-unresolved.h>

Go to the source code of this file.

Data Structures
struct	rtems_rtl_data

Macros
#define	RTL_XGLUE(a, b)   ab
#define	RTL_GLUE(a, b)   RTL_XGLUE(a,b)
#define	RTEMS_RTL_SYMS_GLOBAL_BUCKETS   (32)
#define	RTEMS_RTL_UNRESOLVED_BLOCK_SIZE   (256)
#define	RTEMS_RTL_DEPENDENCY_BLOCK_SIZE   (16)

Typedefs
typedef void(*	rtems_rtl_cdtor) (void)

Functions
void	_rtld_debug_state (void)
rtems_rtl_data *	rtems_rtl_data_unprotected (void)
rtems_rtl_symbols *	rtems_rtl_global_symbols (void)
const char *	rtems_rtl_last_error_unprotected (void)
rtems_chain_control *	rtems_rtl_objects_unprotected (void)
rtems_chain_control *	rtems_rtl_pending_unprotected (void)
rtems_rtl_unresolved *	rtems_rtl_unresolved_unprotected (void)
rtems_rtl_archives *	rtems_rtl_archives_unprotected (void)
void	rtems_rtl_obj_caches (rtems_rtl_obj_cache **symbols, rtems_rtl_obj_cache **strings, rtems_rtl_obj_cache **relocs)
void	rtems_rtl_obj_caches_flush (void)
void	rtems_rtl_obj_decompress (rtems_rtl_obj_comp **decomp, rtems_rtl_obj_cache *cache, int fd, int compression, off_t offset)
void	rtems_rtl_obj_update_flags (uint32_t clear, uint32_t set)
rtems_rtl_data *	rtems_rtl_lock (void)
void	rtems_rtl_unlock (void)
rtems_rtl_obj *	rtems_rtl_check_handle (void *handle)
rtems_rtl_obj *	rtems_rtl_find_obj (const char *name)
rtems_rtl_obj *	rtems_rtl_find_obj_with_symbol (const rtems_rtl_obj_sym *sym)
rtems_rtl_obj *	rtems_rtl_load_object (const char *name, int mode)
bool	rtems_rtl_unload_object (rtems_rtl_obj *obj)
rtems_rtl_obj *	rtems_rtl_load (const char *name, int mode)
bool	rtems_rtl_unload (rtems_rtl_obj *obj)
int	rtems_rtl_get_error (char *message, size_t max_message)
bool	rtems_rtl_path_append (const char *path)
bool	rtems_rtl_path_prepend (const char *path)
void	rtems_rtl_base_sym_global_add (const unsigned char *esyms, unsigned int count, const rtems_rtl_tls_offset *tls_offsets, unsigned int tls_size)
rtems_rtl_obj *	rtems_rtl_baseimage (void)

Variables
struct r_debug	_rtld_debug

Detailed Description

RTEMS Run-Time Linker.

This is the POSIX interface to run-time loading of code into RTEMS.

Macro Definition Documentation

RTEMS_RTL_DEPENDENCY_BLOCK_SIZE

#define RTEMS_RTL_DEPENDENCY_BLOCK_SIZE   (16)

The number of dependency record per block in the dependency table.

RTEMS_RTL_SYMS_GLOBAL_BUCKETS

#define RTEMS_RTL_SYMS_GLOBAL_BUCKETS   (32)

The number of buckets in the global symbol table.

RTEMS_RTL_UNRESOLVED_BLOCK_SIZE

#define RTEMS_RTL_UNRESOLVED_BLOCK_SIZE   (256)

The number of relocation record per block in the unresolved table.

RTL_XGLUE

#define RTL_XGLUE	(		a,
			b
	)		ab

Macros to glue two tokens.

Typedef Documentation

rtems_rtl_cdtor

typedef void(* rtems_rtl_cdtor) (void)

The type of constructor/destructor function.

Function Documentation

_rtld_debug_state()

void _rtld_debug_state

(

void

)

Debugger break function. Call when debugging to have it read the _rtld_debug variable.

rtems_rtl_archives_unprotected()

rtems_rtl_archives * rtems_rtl_archives_unprotected

(

void

)

Get the RTL archives with out locking. This call assumes the RTL is locked.

Returns

rtems_rtl_archives* The RTL acrhives.

Return values

NULL	The RTL data is not initialised.

rtems_rtl_base_sym_global_add()

void rtems_rtl_base_sym_global_add	(	const unsigned char *	esyms,
		unsigned int	count,
		const rtems_rtl_tls_offset *	tls_offsets,
		unsigned int	tls_size
	)

Add an exported symbol table to the global symbol table. This call is normally used by an object file when loaded that contains a global symbol table.

Parameters

esyms	The exported symbol table.
count	The size of the exported symbol table.
tls_offsets	The TLS offsets table. If NULL none provided.
tls_size	The number TLS offset entries in the table.

rtems_rtl_baseimage()

rtems_rtl_obj * rtems_rtl_baseimage

(

void

)

Return the object file descriptor for the base image. The object file descriptor returned is created when the run time linker is initialised.

Assumes the RTL has been locked.

Returns

rtl_obj* The object file descriptor for the base image. NULL is returned if the load fails.

rtems_rtl_check_handle()

rtems_rtl_obj * rtems_rtl_check_handle

(

void *

handle

)

Check a pointer is a valid object file descriptor returning the pointer as that type.

Assumes the RTL has been locked.

Parameters

handle

Pointer to the object file to be validated.

Returns

rtl_obj* The object file descriptor. NULL is returned if invalid.

rtems_rtl_data_unprotected()

rtems_rtl_data * rtems_rtl_data_unprotected

(

void

)

Get the RTL data with out locking. This call assumes the RTL is locked.

Returns

rtems_rtl_data* The RTL data after being locked.

Return values

NULL	The RTL data is not initialised.

rtems_rtl_find_obj()

rtems_rtl_obj * rtems_rtl_find_obj

(

const char *

name

)

Find the object given a file name.

Parameters

name	The name of the object file.

Return values

NULL	No object file with that name found.

Returns

rtems_rtl_obj* The object file descriptor.

rtems_rtl_find_obj_with_symbol()

rtems_rtl_obj * rtems_rtl_find_obj_with_symbol

(

const rtems_rtl_obj_sym *

sym

)

Find the object file a symbol is exported from.

Parameters

sym	The symbol to search with.

Return values

NULL	No object file found.

Returns

rtems_rtl_obj* Reference to the symbol.

rtems_rtl_get_error()

int rtems_rtl_get_error	(	char *	message,
		size_t	max_message
	)

Get the last error message clearing it. This operation locks the run time linker and therefore keeps the RTL thread safe but this call is not thread safe is multiple threads are loading object files at the same time. This call is provided to map to the dlopen family of calls.

Parameters

message	Pointer to a buffer to copy the message into.
max_message	The maximum message that can be copied.

Returns

int The last error number.

rtems_rtl_global_symbols()

rtems_rtl_symbols * rtems_rtl_global_symbols

(

void

)

Get the RTL global symbol table with out locking. This call assumes the RTL is locked.

Returns

rtems_rtl_symbols* The RTL global symbols after being locked.

Return values

NULL	The RTL data is not initialised.

rtems_rtl_last_error_unprotected()

const char * rtems_rtl_last_error_unprotected

(

void

)

Get the RTL last error string with out locking. This call assumes the RTL is locked.

Returns

const char* The RTL's laste error.

Return values

NULL	The RTL data is not initialised.

rtems_rtl_load()

rtems_rtl_obj * rtems_rtl_load	(	const char *	name,
		int	mode
	)

Load an object file. This is the user accessable interface to unloading an object file. See @rtems_rtl_load_object.

Parameters

name	The name of the object file.
mode	The mode of the load as defined by the dlopen call.

Returns

rtl_obj* The object file descriptor. NULL is returned if the load fails.

rtems_rtl_load_object()

rtems_rtl_obj * rtems_rtl_load_object	(	const char *	name,
		int	mode
	)

Load an object file into memory relocating it. It will not be resolved against other symbols in other object files or the base image.

The name can be a file name for an object file or it can be encoded to reference an archive of object modules (static library). This encoding is specific to RTEMS and allows dependences to specify an archive without the searching overhead normally incurred by linkers locating object files in an archive. The file name format rules are:

1. Absolute file references a specific object file in the architecture specific location on the file system.
2. Relative file references an object format file in the search path.
3. Absolute archive and file reference to a specific location in the file system. The archive and file are encoded as 'archive:file [@offset]' where 'archive' is a valid file at the absolute path in the file system, and 'file' is a contained in the archive, and optionally an offset to the 'file' in the 'archive'. If no offset is provided the archive is searched.
4. Relative archive and file in the search path. The encoding is the same as described in item 3 of this list.

Assumes the RTL has been locked.

Parameters

name	The name of the object file.
mode	The mode of the load as defined by the dlopen call.

Returns

rtl_obj* The object file descriptor. NULL is returned if the load fails.

rtems_rtl_lock()

rtems_rtl_data * rtems_rtl_lock

(

void

)

Lock the Run-time Linker.

Returns

rtems_rtl_data* The RTL data after being locked.

Return values

NULL	The RTL data could not be initialised or locked. Typically this means the lock could not be created.

rtems_rtl_obj_caches()

void rtems_rtl_obj_caches	(	rtems_rtl_obj_cache **	symbols,
		rtems_rtl_obj_cache **	strings,
		rtems_rtl_obj_cache **	relocs
	)

Get the RTL symbols, strings, or relocations object file caches. This call assmes the RTL is locked.

Parameters

symbols	Pointer to the location to set the cache into. Returns NULL is rtl is not initialised. If NULL is passed in no value set.
strings	Pointer to the location to set the cache into. Returns NULL is rtl is not initialised. If NULL is passed in no value set.
relocs	Pointer to the location to set the cache into. Returns NULL is rtl is not initialised. If NULL is passed in no value set.

rtems_rtl_obj_caches_flush()

void rtems_rtl_obj_caches_flush

(

void

)

Flush all the object file caches.

rtems_rtl_obj_decompress()

void rtems_rtl_obj_decompress	(	rtems_rtl_obj_comp **	decomp,
		rtems_rtl_obj_cache *	cache,
		int	fd,
		int	compression,
		off_t	offset
	)

Get the RTL decompressor setting for the cache and the offset in the file the compressed stream starts. This call assumes the RTL is locked.

Parameters

decomp	Pointer to the location to set the compressor into. Returns NULL is rtl is not initialised.
cache	The cache to read the file with. Saves needing an extrs buffer.
offset	The offset in the file the compressed stream starts.

rtems_rtl_obj_update_flags()

void rtems_rtl_obj_update_flags	(	uint32_t	clear,
		uint32_t	set
	)

Update the mask in the object files. You can clear flags and then set flags. A zero (0) does not clear or set the flags. This is global to all object files that are laoded.

Parameters

clear	The flag's clear mask, a 0 does not clear any flags.
set	The flag's set mask, a 0 does not set any flags.

rtems_rtl_objects_unprotected()

rtems_chain_control * rtems_rtl_objects_unprotected

(

void

)

Get the RTL objects table with out locking. This call assumes the RTL is locked.

Returns

rtems_chain_control* The RTL objects chain.

Return values

NULL	The RTL data is not initialised.

rtems_rtl_path_append()

bool rtems_rtl_path_append

(

const char *

path

)

Append the path to the search path.

Parameters

path	The path to append.

Return values

false	The path could not be appended.
true	The path was appended.

rtems_rtl_path_prepend()

bool rtems_rtl_path_prepend

(

const char *

path

)

Prepend the path to the search path.

Parameters

path	The path to prepend.

Return values

false	The path could not be prepended.
true	The path was prepended.

rtems_rtl_pending_unprotected()

rtems_chain_control * rtems_rtl_pending_unprotected

(

void

)

Get the RTL pending with out locking. This call assumes the RTL is locked.

Returns

rtems_chain_control* The RTL pending list control.

Return values

NULL	The RTL data is not initialised.

rtems_rtl_unload()

bool rtems_rtl_unload

(

rtems_rtl_obj *

obj

)

Unload an object file. This is the user accessable interface to unloading an object file. See @rtems_rtl_unload_object.

Assumes the RTL has been locked.

Parameters

obj	The object file descriptor.

Return values

true	The object file has been unloaded.
false	The object file could not be unloaded.

rtems_rtl_unload_object()

bool rtems_rtl_unload_object

(

rtems_rtl_obj *

obj

)

Unload an object file. This only happens when the user count is 0.

Assumes the RTL has been locked.

Parameters

obj	The object file descriptor.

Return values

true	The object file has been unloaded.
false	The object file could not be unloaded.

rtems_rtl_unlock()

void rtems_rtl_unlock

(

void

)

Unlock the Run-time Linker.

rtems_rtl_unresolved_unprotected()

rtems_rtl_unresolved * rtems_rtl_unresolved_unprotected

(

void

)

Get the RTL unresolved table with out locking. This call assumes the RTL is locked.

Returns

rtems_rtl_unresolv* The RTL unresolved symbols and reloc records.

Return values

NULL	The RTL data is not initialised.

Variable Documentation

_rtld_debug

struct r_debug _rtld_debug

extern

The global debugger interface variable.