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