Projet_SETI_RISC-V/riscv-gnu-toolchain/newlib/libgloss/riscv/semihost-sys_lseek.c
2023-03-06 14:48:14 +01:00

70 lines
1.2 KiB
C

/*
* Copyright (C) 2020 Embecosm Limited
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <machine/syscall.h>
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#include "semihost_syscall.h"
#include "semihost_fdtable.h"
extern int errno;
/* Set position in a file. */
off_t
_lseek (int file, off_t offset, int dir)
{
long data_block[2];
long flen;
long res;
struct fdentry *fd;
off_t abs_pos;
fd =__get_fdentry (file);
if (fd == NULL)
{
errno = EBADF;
return -1;
}
if (dir == SEEK_CUR && offset == 0)
return fd->pos;
data_block[0] = fd->handle;
switch (dir)
{
case SEEK_SET:
abs_pos = offset;
break;
case SEEK_CUR:
abs_pos = fd->pos + offset;
break;
case SEEK_END:
data_block[1] = 0;
flen = syscall_errno (SEMIHOST_flen, data_block);
if (flen == -1)
return -1;
abs_pos = flen + offset;
break;
default:
errno = EINVAL;
return -1;
}
if (abs_pos < 0)
{
errno = EINVAL;
return -1;
}
data_block[1] = abs_pos;
res = syscall_errno (SEMIHOST_seek, data_block);
if (res == 0)
{
fd->pos = abs_pos;
return abs_pos;
}
return res;
}