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/*
* Copyright (C) 2020 Embecosm Limited
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "semihost_fdtable.h"
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#ifndef RISCV_MAX_OPEN_FILES
#define RISCV_MAX_OPEN_FILES 16
#endif
extern int errno;
extern int _open (const char *, int, ...);
/* fdtable keeps track of the position of each file and is used to map stdin,
stdout and stderr to STDIN_FILENO, STDOUT_FILENO and STDERR_FILENO. */
static struct fdentry fdtable[RISCV_MAX_OPEN_FILES];
/* Initialize fdtable. A handle of -1 denotes an empty entry. */
void __attribute__ ((constructor))
init_semihosting ()
{
int i;
for (i=0; i<RISCV_MAX_OPEN_FILES; i++)
fdtable[i].handle = -1;
/* Set up std streams. Note that the semihost _open() call returns an index
into the fdtable. */
/* stdin. */
i = _open (":tt", O_RDONLY);
fdtable[STDIN_FILENO].handle = fdtable[i].handle;
fdtable[STDIN_FILENO].pos = 0;
/* stdout. */
i = _open (":tt", O_WRONLY|O_CREAT|O_TRUNC);
fdtable[STDOUT_FILENO].handle = fdtable[i].handle;
fdtable[STDOUT_FILENO].pos = 0;
/* stderr. */
i = _open (":tt", O_WRONLY|O_CREAT|O_APPEND);
fdtable[STDERR_FILENO].handle = fdtable[i].handle;
fdtable[STDERR_FILENO].pos = 0;
}
/* Add entry to fdtable. */
int
__add_fdentry (int handle)
{
for (int i=0; i<RISCV_MAX_OPEN_FILES; i++)
if (fdtable[i].handle == -1)
{
fdtable[i].handle = handle;
fdtable[i].pos = 0;
return i;
}
/* Too many open files. */
errno = ENFILE;
return -1;
}
/* Return the fdentry for file or NULL if not found. */
struct fdentry *
__get_fdentry (int file)
{
if (file<0 || file>=RISCV_MAX_OPEN_FILES || fdtable[file].handle == -1)
{
errno = EBADF;
return NULL;
}
return &fdtable[file];
}
/* Remove entry from fdtable. */
void
__remove_fdentry (int file)
{
fdtable[file].handle = -1;
}
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