aboutsummaryrefslogtreecommitdiff
path: root/toys/pending
diff options
context:
space:
mode:
Diffstat (limited to 'toys/pending')
-rw-r--r--toys/pending/microcom.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/toys/pending/microcom.c b/toys/pending/microcom.c
new file mode 100644
index 00000000..d41a9a21
--- /dev/null
+++ b/toys/pending/microcom.c
@@ -0,0 +1,104 @@
+/* microcom.c - Simple serial console.
+ *
+ * Copyright 2017 The Android Open Source Project.
+
+USE_MICROCOM(NEWTOY(microcom, "<1>1s:X", TOYFLAG_BIN))
+
+config MICROCOM
+ bool "microcom"
+ default n
+ help
+ usage: microcom [-s SPEED] [-X]
+
+ Simple serial console.
+
+ -s Set baud rate to SPEED
+ -X Ignore ^@ (send break) and ^X (exit).
+*/
+
+#define FOR_microcom
+#include "toys.h"
+
+GLOBALS(
+ char *speed;
+
+ int fd;
+ struct termios original_stdin_state, original_fd_state;
+)
+
+// Puts `fd` into raw mode, setting the baud rate if `speed` != 0,
+// and saving the original terminal state.
+static void xraw(int fd, const char *name, speed_t speed,
+ struct termios *original)
+{
+ struct termios t;
+
+ if (tcgetattr(fd, &t)) perror_exit("tcgetattr %s", name);
+ *original = t;
+
+ cfmakeraw(&t);
+ if (speed && cfsetspeed(&t, speed)) perror_exit("cfsetspeed");
+
+ if (tcsetattr(fd, TCSAFLUSH, &t)) perror_exit("tcsetattr %s", name);
+}
+
+static void restore_states(int i)
+{
+ tcsetattr(0, TCSAFLUSH, &TT.original_stdin_state);
+ tcsetattr(TT.fd, TCSAFLUSH, &TT.original_fd_state);
+}
+
+void microcom_main(void)
+{
+ speed_t speed = B115200;
+ struct pollfd fds[2];
+ int flags;
+
+ // TODO: move this into lib and support all known baud rates?
+ if (TT.speed) {
+ switch (atolx(TT.speed)) {
+ case 9600: speed = B9600; break;
+ case 19200: speed = B19200; break;
+ case 38400: speed = B38400; break;
+ case 115200: speed = B115200; break;
+ default: error_exit("unknown speed: %s", TT.speed);
+ }
+ }
+
+ // Open with O_NDELAY, but switch back to blocking for reads.
+ TT.fd = xopen(*toys.optargs, O_RDWR | O_NOCTTY | O_NDELAY);
+ flags = fcntl(TT.fd, F_GETFL, 0);
+ if (flags == -1) perror_exit("fcntl F_GETFL");
+ if (fcntl(TT.fd, F_SETFL, flags & ~O_NDELAY)) perror_exit("fcntl F_SETFL");
+
+ // Set both input and output to raw mode.
+ xraw(TT.fd, "fd", speed, &TT.original_fd_state);
+ xraw(0, "stdin", 0, &TT.original_stdin_state);
+ // ...and arrange to restore things, however we may exit.
+ sigatexit(restore_states);
+
+ fds[0].fd = TT.fd;
+ fds[0].events = POLLIN;
+ fds[1].fd = 0;
+ fds[1].events = POLLIN;
+
+ while (poll(fds, 2, -1) > 0) {
+ char buf[BUFSIZ];
+
+ // Read from connection, write to stdout.
+ if (fds[0].revents) {
+ ssize_t n = read(TT.fd, buf, sizeof(buf));
+ if (n > 0) xwrite(0, buf, n);
+ else break;
+ }
+
+ // Read from stdin, write to connection.
+ if (fds[1].revents) {
+ if (read(0, buf, 1) == 1) {
+ if (buf[0] == 0) tcsendbreak(TT.fd, 0);
+ else if (buf[0] == ('X'-'@')) break;
+ else xwrite(TT.fd, buf, 1);
+ } else break;
+ }
+ }
+}