/****************************************************************************
* binfmt/libelf/libelf_read.c
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <elf32.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/binfmt/elf.h>
/****************************************************************************
* Pre-Processor Definitions
****************************************************************************/
#undef ELF_DUMP_READDATA /* Define to dump all file data read */
#define DUMPER lib_rawprintf /* If ELF_DUMP_READDATA is defined, this
* is the API used to dump data */
/****************************************************************************
* Private Constant Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: elf_dumpreaddata
****************************************************************************/
#if defined(ELF_DUMP_READDATA)
static inline void elf_dumpreaddata(char *buffer, int buflen)
{
uint32_t *buf32 = (uint32_t*)buffer;
int i;
int j;
for (i = 0; i < buflen; i += 32)
{
DUMPER("%04x:", i);
for (j = 0; j < 32; j += sizeof(uint32_t))
{
DUMPER(" %08x", *buf32++);
}
DUMPER("\n");
}
}
#else
# define elf_dumpreaddata(b,n)
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* 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 responsibile for assuring that that address
* environment is in place before calling this function (i.e., that
* elf_addrenv_select() has been called if CONFIG_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)
{
ssize_t nbytes; /* Number of bytes read */
off_t rpos; /* Position returned by lseek */
bvdbg("Read %ld bytes from offset %ld\n", (long)readsize, (long)offset);
/* Loop until all of the requested data has been read. */
while (readsize > 0)
{
/* Seek to the next read position */
rpos = lseek(loadinfo->filfd, offset, SEEK_SET);
if (rpos != offset)
{
int errval = errno;
bdbg("Failed to seek to position %ld: %d\n", (long)offset, errval);
return -errval;
}
/* Read the file data at offset into the user buffer */
nbytes = read(loadinfo->filfd, buffer, readsize);
if (nbytes < 0)
{
int errval = errno;
/* EINTR just means that we received a signal */
if (errval != EINTR)
{
bdbg("Read of .data failed: %d\n", errval);
return -errval;
}
}
else if (nbytes == 0)
{
bdbg("Unexpected end of file\n");
return -ENODATA;
}
else
{
readsize -= nbytes;
buffer += nbytes;
offset += nbytes;
}
}
elf_dumpreaddata(buffer, readsize);
return OK;
}
