binfmt/libelf/libelf.h

/****************************************************************************
 * binfmt/libelf/libelf.h
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

#ifndef __BINFMT_LIBELF_LIBELF_H
#define __BINFMT_LIBELF_LIBELF_H

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/binfmt/elf.h>

/****************************************************************************
 * Public Function Prototypes
 ****************************************************************************/

/****************************************************************************
 * Name: elf_verifyheader
 *
 * Description:
 *   Given the header from a possible ELF executable, verify that it is
 *   an ELF executable.
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

int elf_verifyheader(FAR const Elf_Ehdr *header);

/****************************************************************************
 * Name: elf_read
 *
 * Description:
 *   Read 'readsize' bytes from the object file at 'offset'.  The data is
 *   read into 'buffer.' If 'buffer' is part of the ELF address environment,
 *   then the caller is responsible for assuring that that address
 *   environment is in place before calling this function (i.e., that
 *   elf_addrenv_select() has been called if CONFIG_ARCH_ADDRENV=y).
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

int elf_read(FAR struct elf_loadinfo_s *loadinfo, FAR uint8_t *buffer,
             size_t readsize, off_t offset);

/****************************************************************************
 * Name: elf_loadphdrs
 *
 * Description:
 *   Loads program headers into memory.
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

int elf_loadphdrs(FAR struct elf_loadinfo_s *loadinfo);

/****************************************************************************
 * Name: elf_loadshdrs
 *
 * Description:
 *   Loads section headers into memory.
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

int elf_loadshdrs(FAR struct elf_loadinfo_s *loadinfo);

/****************************************************************************
 * Name: elf_findsection
 *
 * Description:
 *   A section by its name.
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *   sectname - Name of the section to find
 *
 * Returned Value:
 *   On success, the index to the section is returned; A negated errno value
 *   is returned on failure.
 *
 ****************************************************************************/

int elf_findsection(FAR struct elf_loadinfo_s *loadinfo,
                    FAR const char *sectname);

/****************************************************************************
 * Name: elf_findsymtab
 *
 * Description:
 *   Find the symbol table section.
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

int elf_findsymtab(FAR struct elf_loadinfo_s *loadinfo);

/****************************************************************************
 * Name: elf_readsym
 *
 * Description:
 *   Read the ELF symbol structure at the specified index into memory.
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *   index    - Symbol table index
 *   sym      - Location to return the table entry
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

int elf_readsym(FAR struct elf_loadinfo_s *loadinfo, int index,
                FAR Elf_Sym *sym);

/****************************************************************************
 * Name: elf_symvalue
 *
 * Description:
 *   Get the value of a symbol.  The updated value of the symbol is returned
 *   in the st_value field of the symbol table entry.
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *   sym      - Symbol table entry (value might be undefined)
 *   exports  - The symbol table to use for resolving undefined symbols.
 *   nexports - Number of symbols in the symbol table.
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 *   EINVAL - There is something inconsistent in the symbol table (should
 *            only happen if the file is corrupted)
 *   ENOSYS - Symbol lies in common
 *   ESRCH  - Symbol has no name
 *   ENOENT - Symbol undefined and not provided via a symbol table
 *
 ****************************************************************************/

int elf_symvalue(FAR struct elf_loadinfo_s *loadinfo, FAR Elf_Sym *sym,
                 FAR const struct symtab_s *exports, int nexports);

/****************************************************************************
 * Name: elf_freebuffers
 *
 * Description:
 *  Release all working buffers.
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

int elf_freebuffers(FAR struct elf_loadinfo_s *loadinfo);

/****************************************************************************
 * Name: elf_allocbuffer
 *
 * Description:
 *   Perform the initial allocation of the I/O buffer, if it has not already
 *   been allocated.
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

int elf_allocbuffer(FAR struct elf_loadinfo_s *loadinfo);

/****************************************************************************
 * Name: elf_reallocbuffer
 *
 * Description:
 *   Increase the size of I/O buffer by the specified buffer increment.
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

int elf_reallocbuffer(FAR struct elf_loadinfo_s *loadinfo, size_t increment);

/****************************************************************************
 * Name: elf_findctors
 *
 * Description:
 *   Find C++ static constructors.
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

#ifdef CONFIG_BINFMT_CONSTRUCTORS
int elf_loadctors(FAR struct elf_loadinfo_s *loadinfo);
#endif

/****************************************************************************
 * Name: elf_loaddtors
 *
 * Description:
 *  Load pointers to static destructors into an in-memory array.
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *
 * Returned Value:
 *   0 (OK) is returned on success and a negated errno is returned on
 *   failure.
 *
 ****************************************************************************/

#ifdef CONFIG_BINFMT_CONSTRUCTORS
int elf_loaddtors(FAR struct elf_loadinfo_s *loadinfo);
#endif

/****************************************************************************
 * Name: elf_addrenv_alloc
 *
 * Description:
 *   Allocate memory for the ELF image (textalloc and dataalloc).
 *   If CONFIG_ARCH_ADDRENV=n, textalloc will be allocated using kmm_zalloc()
 *   and dataalloc will be a offset from textalloc.
 *   If CONFIG_ARCH_ADDRENV=y, then textalloc and dataalloc will be allocated
 *   using up_addrenv_create().
 *   In either case, there will be a unique instance of textalloc and
 *   dataalloc (and stack) for each instance of a process.
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *   textsize - The size (in bytes) of the .text address environment needed
 *     for the ELF image (read/execute).
 *   datasize - The size (in bytes) of the .bss/.data address environment
 *     needed for the ELF image (read/write).
 *   heapsize - The initial size (in bytes) of the heap address environment
 *     needed by the task.  This region may be read/write only.
 *
 * Returned Value:
 *   Zero (OK) on success; a negated errno value on failure.
 *
 ****************************************************************************/

int elf_addrenv_alloc(FAR struct elf_loadinfo_s *loadinfo, size_t textsize,
                      size_t datasize, size_t heapsize);

/****************************************************************************
 * Name: elf_addrenv_select
 *
 * Description:
 *   Temporarily select the task's address environment.
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *
 * Returned Value:
 *   Zero (OK) on success; a negated errno value on failure.
 *
 ****************************************************************************/

#ifdef CONFIG_ARCH_ADDRENV
int elf_addrenv_select(FAR struct elf_loadinfo_s *loadinfo);
#endif

/****************************************************************************
 * Name: elf_addrenv_restore
 *
 * Description:
 *   Restore the address environment before elf_addrenv_select() was called..
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *
 * Returned Value:
 *   Zero (OK) on success; a negated errno value on failure.
 *
 ****************************************************************************/

#ifdef CONFIG_ARCH_ADDRENV
int elf_addrenv_restore(FAR struct elf_loadinfo_s *loadinfo);
#endif

/****************************************************************************
 * Name: elf_addrenv_free
 *
 * Description:
 *   Release the address environment previously created by
 *   elf_addrenv_alloc().  This function  is called only under certain error
 *   conditions after the module has been loaded but not yet started.
 *   After the module has been started, the address environment will
 *   automatically be freed when the module exits.
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *
 * Returned Value:
 *   None.
 *
 ****************************************************************************/

void elf_addrenv_free(FAR struct elf_loadinfo_s *loadinfo);

#endif /* __BINFMT_LIBELF_LIBELF_H */