incubator-nuttx/libs/libc/modlib/modlib_read.c

133 lines
4.2 KiB
C

/****************************************************************************
* libs/libc/modlib/modlib_read.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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 <inttypes.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include <nuttx/lib/modlib.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#undef ELF_DUMP_READDATA /* Define to dump all file data read */
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: modlib_dumpreaddata
****************************************************************************/
#ifdef ELF_DUMP_READDATA
# define modlib_dumpreaddata(b,n) binfodumpbuffer("modlib_read",b,n)
#else
# define modlib_dumpreaddata(b,n)
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: modlib_read
*
* Description:
* Read 'readsize' bytes from the object file at 'offset'. The data is
* read into 'buffer.'
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int modlib_read(FAR struct mod_loadinfo_s *loadinfo, FAR uint8_t *buffer,
size_t readsize, off_t offset)
{
size_t nsize = readsize;
ssize_t nbytes; /* Number of bytes read */
off_t rpos; /* Position returned by lseek */
int errval;
binfo("Read %zu bytes from offset %" PRIdOFF "\n", readsize, offset);
/* Loop until all of the requested data has been read. */
/* Seek to the read position */
rpos = _NX_SEEK(loadinfo->filfd, offset, SEEK_SET);
if (rpos != offset)
{
errval = _NX_GETERRNO(rpos);
berr("ERROR: Failed to seek to position %" PRIdOFF ": %d\n",
offset, errval);
return -errval;
}
while (readsize > 0)
{
/* Read the file data at offset into the user buffer */
nbytes = _NX_READ(loadinfo->filfd,
buffer + nsize - readsize, readsize);
if (nbytes < 0)
{
errval = _NX_GETERRNO(nbytes);
/* EINTR just means that we received a signal */
if (errval != EINTR)
{
berr("ERROR: Read from offset %" PRIdOFF " failed: %d\n",
(off_t)(offset + nsize - readsize), errval);
return -errval;
}
}
else if (nbytes == 0)
{
berr("ERROR: Unexpected end of file\n");
return -ENODATA;
}
else
{
readsize -= nbytes;
}
}
modlib_dumpreaddata(buffer, nsize);
return OK;
}