1 /* microcom.c - Simple serial console.
2 *
3 * Copyright 2017 The Android Open Source Project.
4
5 USE_MICROCOM(NEWTOY(microcom, "<1>1s:X", TOYFLAG_USR|TOYFLAG_BIN))
6
7 config MICROCOM
8 bool "microcom"
9 default y
10 help
11 usage: microcom [-s SPEED] [-X] DEVICE
12
13 Simple serial console.
14
15 -s Set baud rate to SPEED
16 -X Ignore ^@ (send break) and ^] (exit)
17 */
18
19 #define FOR_microcom
20 #include "toys.h"
21
GLOBALS(char * s;int fd;struct termios original_stdin_state,original_fd_state;)22 GLOBALS(
23 char *s;
24
25 int fd;
26 struct termios original_stdin_state, original_fd_state;
27 )
28
29 // TODO: tty_sigreset outputs ansi escape sequences, how to disable?
30 static void restore_states(int i)
31 {
32 tcsetattr(0, TCSAFLUSH, &TT.original_stdin_state);
33 tcsetattr(TT.fd, TCSAFLUSH, &TT.original_fd_state);
34 }
35
microcom_main(void)36 void microcom_main(void)
37 {
38 struct pollfd fds[2];
39 int i, speed;
40
41 if (!TT.s) speed = 115200;
42 else speed = atoi(TT.s);
43
44 // Open with O_NDELAY, but switch back to blocking for reads.
45 TT.fd = xopen(*toys.optargs, O_RDWR | O_NOCTTY | O_NDELAY);
46 if (-1==(i = fcntl(TT.fd, F_GETFL, 0)) || fcntl(TT.fd, F_SETFL, i&~O_NDELAY))
47 perror_exit_raw(*toys.optargs);
48
49 // Set both input and output to raw mode.
50 xset_terminal(TT.fd, 1, speed, &TT.original_fd_state);
51 set_terminal(0, 1, 0, &TT.original_stdin_state);
52 // ...and arrange to restore things, however we may exit.
53 sigatexit(restore_states);
54
55 fds[0].fd = TT.fd;
56 fds[0].events = POLLIN;
57 fds[1].fd = 0;
58 fds[1].events = POLLIN;
59
60 while (poll(fds, 2, -1) > 0) {
61 char buf[BUFSIZ];
62
63 // Read from connection, write to stdout.
64 if (fds[0].revents) {
65 ssize_t n = read(TT.fd, buf, sizeof(buf));
66 if (n > 0) xwrite(0, buf, n);
67 else break;
68 }
69
70 // Read from stdin, write to connection.
71 if (fds[1].revents) {
72 if (read(0, buf, 1) != 1) break;
73 if (!(toys.optflags & FLAG_X)) {
74 if (!*buf) {
75 tcsendbreak(TT.fd, 0);
76 continue;
77 } else if (*buf == (']'-'@')) break;
78 }
79 xwrite(TT.fd, buf, 1);
80 }
81 }
82 }
83