incubator-nuttx/binfmt/libelf/libelf_read.c

149 lines
4.7 KiB
C

/****************************************************************************
* binfmt/libelf/libelf_read.c
*
* 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include <nuttx/binfmt/elf.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#undef ELF_DUMP_READDATA /* Define to dump all file data read */
/****************************************************************************
* Private Constant Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: elf_dumpreaddata
****************************************************************************/
#if defined(ELF_DUMP_READDATA)
static inline void elf_dumpreaddata(FAR char *buffer, int buflen)
{
FAR uint32_t *buf32 = (FAR uint32_t *)buffer;
int i;
int j;
for (i = 0; i < buflen; i += 32)
{
syslog(LOG_DEBUG, "%04x:", i);
for (j = 0; j < 32; j += sizeof(uint32_t))
{
syslog(LOG_DEBUG, " %08x", *buf32++);
}
syslog(LOG_DEBUG, "\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 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)
{
ssize_t nbytes; /* Number of bytes read */
off_t rpos; /* Position returned by lseek */
binfo("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 = nx_seek(loadinfo->filfd, offset, SEEK_SET);
if (rpos != offset)
{
berr("Failed to seek to position %lu: %d\n",
(unsigned long)offset, (int)rpos);
return rpos;
}
/* Read the file data at offset into the user buffer */
nbytes = nx_read(loadinfo->filfd, buffer, readsize);
if (nbytes < 0)
{
/* EINTR just means that we received a signal */
if (nbytes != -EINTR)
{
berr("Read from offset %lu failed: %d\n",
(unsigned long)offset, (int)nbytes);
return nbytes;
}
}
else if (nbytes == 0)
{
berr("Unexpected end of file\n");
return -ENODATA;
}
else
{
readsize -= nbytes;
buffer += nbytes;
offset += nbytes;
}
}
elf_dumpreaddata(buffer, readsize);
return OK;
}