newlib/libgloss/nios2/io-lseek.c

53 lines
1.5 KiB
C

/*
* io-lseek.c --
*
* Copyright (c) 2006 CodeSourcery Inc
* Copyright (c) 2018 Mentor Graphics
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice is included verbatim in any distributions. No written agreement,
* license, or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their authors
* and need not follow the licensing terms described here, provided that
* the new terms are clearly indicated on the first page of each file where
* they apply.
*/
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#define IO lseek
#include "io.h"
/*
* lseek -- reposition a file descriptor
* input parameters:
* 0 : file descriptor
* 1 : high word of offset
* 2 : low word of offset
* 3 : seek flag
* output parameters:
* 0 : high word of result
* 1 : low word of result
* 2 : errno
*/
off_t lseek (int fd, off_t offset, int whence)
{
#if HOSTED
gdb_parambuf_t parameters;
parameters[0] = (uint32_t) fd;
parameters[1] = (uint32_t) ((int64_t)offset >> 32);
parameters[2] = (uint32_t) (offset & 0xffffffff);
parameters[3] = __hosted_to_gdb_lseek_flags (whence);
__io_hosted (HOSTED_LSEEK, parameters);
errno = __hosted_from_gdb_errno (parameters[2]);
return ((uint64_t)parameters[0] << 32) | ((uint64_t)parameters[1]);
#else
errno = ENOSYS;
return -1;
#endif
}