Patrick Georgi | 7333a11 | 2020-05-08 20:48:04 +0200 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
Denis 'GNUtoo' Carikli | bfe0789 | 2016-02-21 14:27:21 +0100 | [diff] [blame] | 2 | |
| 3 | #include <errno.h> |
| 4 | #include <limits.h> |
| 5 | #include <stdarg.h> |
| 6 | #include <stdio.h> |
| 7 | #include <stdlib.h> |
| 8 | #include <sys/io.h> |
| 9 | |
| 10 | #define POST_DEFAULT_IO_PORT 0x80 |
| 11 | |
| 12 | void usage(char *progname, const char *error, ...) |
| 13 | { |
| 14 | printf("Usage: %s <VALUE> [PORT]\n", progname); |
| 15 | printf("The VALUE argument is an integer between 0x00 and 0xff\n"); |
| 16 | printf("The PORT argument is an integer between 0x00 and 0xffff\n"); |
| 17 | |
| 18 | if (error) { |
| 19 | va_list args; |
| 20 | |
| 21 | va_start(args, error); |
| 22 | vprintf(error, args); |
| 23 | va_end(args); |
| 24 | }; |
| 25 | } |
| 26 | |
| 27 | void check_int(long val, int min, int max, int err, char *string, char *endptr, |
| 28 | char *progname) |
| 29 | { |
| 30 | if (val < min || val > max) { |
| 31 | usage(progname, |
| 32 | "\nError: The value has to be between 0x%x and 0x%x\n", |
| 33 | min, max); |
| 34 | exit(EXIT_FAILURE); |
| 35 | } |
| 36 | |
| 37 | if (endptr == string || *endptr != '\0') { |
| 38 | usage(progname, "\nError: An integer is required\n"); |
| 39 | exit(EXIT_FAILURE); |
| 40 | } |
| 41 | |
| 42 | if ((err) && (!val)) { |
| 43 | perror("strtol"); |
| 44 | exit(EXIT_FAILURE); |
| 45 | } |
| 46 | } |
| 47 | |
| 48 | int main(int argc, char *argv[]) |
| 49 | { |
| 50 | unsigned long val; |
| 51 | unsigned long port = POST_DEFAULT_IO_PORT; |
| 52 | char *endptr; |
| 53 | int err; |
| 54 | |
| 55 | if (argc != 2 && argc != 3) { |
| 56 | usage(argv[0], NULL); |
| 57 | exit(EXIT_FAILURE); |
| 58 | } |
| 59 | |
| 60 | val = strtol(argv[1], &endptr, 0); |
| 61 | err = errno; |
| 62 | check_int(val, 0x00, 0xff, err, argv[1], endptr, argv[0]); |
| 63 | |
| 64 | if (argc > 2) { |
| 65 | port = strtol(argv[2], &endptr, 0); |
| 66 | err = errno; |
| 67 | check_int(port, 0x0000, 0xffff, err, argv[2], endptr, argv[0]); |
| 68 | } |
| 69 | |
| 70 | err = iopl(3); |
| 71 | if (err == -1) { |
| 72 | perror("Not root"); |
| 73 | exit(EXIT_FAILURE); |
| 74 | } |
| 75 | |
| 76 | outb(val, port); |
| 77 | |
| 78 | return 0; |
| 79 | } |