Linkable loadable extensions

Linkable loadable extensions. More...

Modules
	ELF data types and defines
	ELF types and parsing.
	LLEXT symbols
	Linkable loadable extension symbol.
	Linkable loadable extensions buffer loader
	LLEXT buffer loader.
	Loader context for llext
	Loader context for llext.

Data Structures
struct	llext
	Linkable loadable extension. More...

Enumerations
enum	llext_mem {   LLEXT_MEM_TEXT , LLEXT_MEM_DATA , LLEXT_MEM_RODATA , LLEXT_MEM_BSS ,   LLEXT_MEM_COUNT }
	Enum of memory regions for lookup tables. More...

Functions
sys_slist_t *	llext_list (void)
	List head of loaded extensions.
struct llext *	llext_by_name (const char *name)
	Find an llext by name.
int	llext_load (struct llext_loader *loader, const char *name, struct llext **ext)
	Load and link an extension.
void	llext_unload (struct llext *ext)
	Unload an extension.
const void *const	llext_find_sym (const struct llext_symtable *sym_table, const char *sym_name)
	Find the address for an arbitrary symbol name.
int	llext_call_fn (struct llext *ext, const char *sym_name)
	Call a function by name.
void	arch_elf_relocate (elf_rel_t *rel, uintptr_t opaddr, uintptr_t opval)
	Architecture specific function for updating op codes given a relocation.

Detailed Description

Linkable loadable extensions.

Enumeration Type Documentation

llext_mem

enum llext_mem

#include <zephyr/llext/llext.h>

Enum of memory regions for lookup tables.

Enumerator
LLEXT_MEM_TEXT
LLEXT_MEM_DATA
LLEXT_MEM_RODATA
LLEXT_MEM_BSS
LLEXT_MEM_COUNT

Function Documentation

arch_elf_relocate()

void arch_elf_relocate	(	elf_rel_t *	rel,
		uintptr_t	opaddr,
		uintptr_t	opval
	)

#include <zephyr/llext/llext.h>

Architecture specific function for updating op codes given a relocation.

Elf files contain a series of relocations described in a section. These relocation instructions are architecture specific and each architecture supporting extensions must implement this. They are instructions on how to rewrite opcodes given the actual placement of some symbolic data such as a section, function, or object.

Parameters

[in]	rel	Relocation data provided by elf
[in]	opaddr	Address of operation to rewrite with relocation
[in]	opval	Value of looked up symbol to relocate

llext_by_name()

struct llext * llext_by_name

(

const char *

name

)

#include <zephyr/llext/llext.h>

Find an llext by name.

Parameters

[in]

name

String name of the llext

Return values

NULL	if no llext not found
llext	if llext found

llext_call_fn()

int llext_call_fn	(	struct llext *	ext,
		const char *	sym_name
	)

#include <zephyr/llext/llext.h>

Call a function by name.

Expects a symbol representing a void fn(void) style function exists and may be called.

Parameters

[in]	ext	Extension to call function in
[in]	sym_name	Function name (exported symbol) in the extension

Return values

0	success
-EINVAL	invalid symbol name

llext_find_sym()

const void *const llext_find_sym	(	const struct llext_symtable *	sym_table,
		const char *	sym_name
	)

#include <zephyr/llext/llext.h>

Find the address for an arbitrary symbol name.

Parameters

[in]	sym_table	Symbol table to lookup symbol in, if NULL uses base table
[in]	sym_name	Symbol name to find

Return values

NULL	if no symbol found
addr	Address of symbol in memory if found

llext_list()

sys_slist_t * llext_list

(

void

)

#include <zephyr/llext/llext.h>

List head of loaded extensions.

llext_load()

int llext_load	(	struct llext_loader *	loader,
		const char *	name,
		struct llext **	ext
	)

#include <zephyr/llext/llext.h>

Load and link an extension.

Loads relevant ELF data into memory and provides a structure to work with it.

Only relocatable ELF files are currently supported (partially linked).

Parameters

[in]	loader	An extension loader that provides input data and context
[in]	name	A string identifier for the extension
[out]	ext	A pointer to a statically allocated llext struct

Return values

0	Success
-ENOMEM	Not enough memory
-EINVAL	Invalid ELF stream

llext_unload()

void llext_unload

(

struct llext *

ext

)

#include <zephyr/llext/llext.h>

Unload an extension.

Parameters

[in]

ext

Extension to unload