lib/libc/newlib/libc-hooks.c

/*
 * Copyright (c) 2015, Intel Corporation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1) Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2) Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3) Neither the name of Intel Corporation nor the names of its contributors
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <errno.h>
#include <stdio.h>
#include <sys/stat.h>

#define HEAP_SIZE 4096
unsigned char heap[HEAP_SIZE];
unsigned int heap_sz = 0;

static int _stdout_hook_default(int c)
{
	(void)(c);  /* Prevent warning about unused argument */

	return EOF;
}

static int (*_stdout_hook)(int) = _stdout_hook_default;

void __stdout_hook_install(int (*hook)(int))
{
	_stdout_hook = hook;
}

static unsigned char _stdin_hook_default(void)
{
	return 0;
}

static unsigned char (*_stdin_hook)(void) = _stdin_hook_default;

void __stdin_hook_install(unsigned char (*hook)(void))
{
	_stdin_hook = hook;
}

int read(int fd, char *buf, int nbytes)
{
	int i = 0;

	for (i = 0; i < nbytes; i++) {
		*(buf + i) = _stdin_hook();
		if ((*(buf + i) == '\n') || (*(buf + i) == '\r')) {
			i++;
			break;
		}
	}
	return i;
}

int write(int fd, char *buf, int nbytes)
{
	int i;

	for (i = 0; i < nbytes; i++) {
		if (*(buf + i) == '\n') {
			_stdout_hook('\r');
		}
		_stdout_hook(*(buf + i));
	}
	return nbytes;
}

int fstat(int fd, struct stat *buf)
{
	buf->st_mode = S_IFCHR;       /* Always pretend to be a tty */
	buf->st_blksize = 0;

	return 0;
}

int isatty(int file)
{
	return 1;
}


int kill(int i, int j)
{
	return 0;
}

int getpid(void)
{
	return 0;
}

int _fstat(int file, struct stat *st)
{
	st->st_mode = S_IFCHR;
	return 0;
}


void exit(int status)
{
	write(1, "exit", 4);
	while (1) {
		;
	}
}

int close(int file)
{
	return -1;
}

int lseek(int file, int ptr, int dir)
{
	return 0;
}

void *sbrk(int count)
{
	void *ptr = heap + heap_sz;

	if ((heap_sz + count) <= HEAP_SIZE) {
		heap_sz += count;
		return ptr;
	} else {
		return (void *)-1;
	}
}