llext.h

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/*
 * Copyright (c) 2023 Intel Corporation
 * Copyright (c) 2024 Schneider Electric
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_LLEXT_H
#define ZEPHYR_LLEXT_H
 
#include <zephyr/sys/slist.h>
#include <zephyr/llext/elf.h>
#include <zephyr/llext/symbol.h>
#include <zephyr/kernel.h>
#include <sys/types.h>
#include <stdbool.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
enum llext_mem {
        LLEXT_MEM_TEXT,         
        LLEXT_MEM_DATA,         
        LLEXT_MEM_RODATA,       
        LLEXT_MEM_BSS,          
        LLEXT_MEM_EXPORT,       
        LLEXT_MEM_SYMTAB,       
        LLEXT_MEM_STRTAB,       
        LLEXT_MEM_SHSTRTAB,     
        LLEXT_MEM_PREINIT,      
        LLEXT_MEM_INIT,         
        LLEXT_MEM_FINI,         
        LLEXT_MEM_COUNT,        
};
 
/* Number of memory partitions used by LLEXT */
#define LLEXT_MEM_PARTITIONS (LLEXT_MEM_BSS+1)
 
struct llext_loader;
/* Maximim number of dependency LLEXTs */
#define LLEXT_MAX_DEPENDENCIES 8
 
struct llext {
        sys_snode_t _llext_list;
 
#ifdef CONFIG_USERSPACE
        struct k_mem_partition mem_parts[LLEXT_MEM_PARTITIONS];
        struct k_mem_domain mem_domain;
#endif
 
        char name[16];
 
        void *mem[LLEXT_MEM_COUNT];
 
        bool mem_on_heap[LLEXT_MEM_COUNT];
 
        size_t mem_size[LLEXT_MEM_COUNT];
 
        size_t alloc_size;
 
        struct llext_symtable sym_tab;
 
        struct llext_symtable exp_tab;
 
        unsigned int use_count;
 
        struct llext *dependency[LLEXT_MAX_DEPENDENCIES];
 
        unsigned int sect_cnt;
        elf_shdr_t *sect_hdrs;
        bool sect_hdrs_on_heap;
};
 
static inline const elf_shdr_t *llext_section_headers(const struct llext *ext)
{
        return ext->sect_hdrs;
}
 
static inline unsigned int llext_section_count(const struct llext *ext)
{
        return ext->sect_cnt;
}
 
struct llext_load_param {
        bool relocate_local;
        bool pre_located;
        bool (*section_detached)(const elf_shdr_t *shdr);
};
 
#define LLEXT_LOAD_PARAM_DEFAULT { .relocate_local = true, }
 
struct llext *llext_by_name(const char *name);
 
int llext_iterate(int (*fn)(struct llext *ext, void *arg), void *arg);
 
int llext_load(struct llext_loader *loader, const char *name, struct llext **ext,
               const struct llext_load_param *ldr_parm);
 
int llext_unload(struct llext **ext);
 
typedef void (*llext_entry_fn_t)(void *user_data);
 
int llext_bringup(struct llext *ext);
 
int llext_teardown(struct llext *ext);
 
void llext_bootstrap(struct llext *ext, llext_entry_fn_t entry_fn, void *user_data);
 
__syscall ssize_t llext_get_fn_table(struct llext *ext, bool is_init, void *buf, size_t size);
 
const void *llext_find_sym(const struct llext_symtable *sym_table, const char *sym_name);
 
int llext_call_fn(struct llext *ext, const char *sym_name);
 
int llext_add_domain(struct llext *ext, struct k_mem_domain *domain);
 
int arch_elf_relocate(elf_rela_t *rel, uintptr_t loc,
                             uintptr_t sym_base_addr, const char *sym_name, uintptr_t load_bias);
 
ssize_t llext_find_section(struct llext_loader *loader, const char *search_name);
 
int llext_get_section_header(struct llext_loader *loader, struct llext *ext,
                             const char *search_name, elf_shdr_t *shdr);
 
void arch_elf_relocate_local(struct llext_loader *loader, struct llext *ext, const elf_rela_t *rel,
                             const elf_sym_t *sym, size_t got_offset,
                             const struct llext_load_param *ldr_parm);
 
void arch_elf_relocate_global(struct llext_loader *loader, struct llext *ext, const elf_rela_t *rel,
                              const elf_sym_t *sym, size_t got_offset, const void *link_addr);
 
#ifdef __cplusplus
}
#endif
 
#include <zephyr/syscalls/llext.h>
 
#endif /* ZEPHYR_LLEXT_H */