1 /*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright © 2021 Keith Packard
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
17 *
18 * 3. Neither the name of the copyright holder nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
33 * OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <unistd.h>
39
40 static int
e9_putc(char c,FILE * file)41 e9_putc(char c, FILE *file)
42 {
43 (void) file;
44 __asm__("out %%al, $0xe9" : : "a" ((int) c));
45 return (unsigned char) c;
46 }
47
48 static int
e9_getc(FILE * file)49 e9_getc(FILE *file)
50 {
51 (void) file;
52 return EOF;
53 }
54
55 static FILE __stdio = FDEV_SETUP_STREAM(e9_putc, e9_getc, NULL, _FDEV_SETUP_RW);
56
57 #ifdef __strong_reference
58 #define STDIO_ALIAS(x) __strong_reference(stdin, x);
59 #else
60 #define STDIO_ALIAS(x) FILE *const x = &__stdio;
61 #endif
62
63 FILE *const stdin = &__stdio;
64 STDIO_ALIAS(stdout);
65 STDIO_ALIAS(stderr);
66
