Add command mode

This mode is entered before serial line begins. Currently implemented
commands are: dtr, rst and go. "dtr" and "rst" are the same as -d and -r
options, "go" ends command mode and enters serial line interaction.

This is intended for use by novaboot in this way: Novaboot connects to
the serial line to be sure that the target is not occupied. Then it
copies the images, which can take long time, and after that it sends
reset command to reset the target. Without this, the target is reset (by
-d or -r) before copying the images and after that it may be too late to
communicate with the bootloader.

diff --git a/sterm.c b/sterm.c
index 34f484554683990d7e84a78a33af1b046831df2e..3e1a5736cbd5d58f406d8bb73359a8857ee5ee97 100644 (file)
--- a/sterm.c
+++ b/sterm.c
@@ -48,6 +48,7 @@
 #define TOSTRING(val) STRINGIFY(val)
 #define CHECK(cmd) ({ int ret = (cmd); if (ret == -1) { perror(#cmd " line " TOSTRING(__LINE__)); exit(1); }; ret; })
 #define CHECKPTR(cmd) ({ void *ptr = (cmd); if (ptr == (void*)-1) { perror(#cmd " line " TOSTRING(__LINE__)); exit(1); }; ptr; })
+#define CHECKNULL(cmd) ({ void *ptr = (cmd); if (ptr == NULL) { perror(#cmd " line " TOSTRING(__LINE__)); exit(1); }; ptr; })
 
 #define VERBOSE(format, ...) do { if (verbose) fprintf(stderr, "sterm: " format, ##__VA_ARGS__); } while (0)
 
@@ -80,7 +81,7 @@ void sighandler(int arg)
        exit(0); /* Invoke exit handlers */
 }
 
-int dtr_rts_arg(const char option)
+int dtr_rts_arg(const char option, const char *optarg)
 {
        int val = -1;
 
@@ -93,7 +94,7 @@ int dtr_rts_arg(const char option)
                        case '+': val = +1; break;
                        case '-': val = -1; break;
                        default:
-                               fprintf(stderr, "Unknown -%c argument: %s", option, optarg);
+                               fprintf(stderr, "Unknown -%c argument: %s\n", option, optarg);
                                exit(1);
                        }
                }
@@ -124,6 +125,7 @@ void usage(const char* argv0)
        fprintf(stderr, "Usage: %s [options] <device>\n", argv0);
        fprintf(stderr,
                "Options:\n"
+               "  -c        enter command mode\n"
                "  -d[PULSE] make pulse on DTR\n"
                "  -e        ignore '~.' escape sequence\n"
                "  -n        do not switch the device to raw mode\n"
@@ -158,6 +160,33 @@ void pulse(int fd, int dtr, int rts)
        CHECK(ioctl(fd, TIOCMSET, &status));
 }
 
+void handle_commands(int fd)
+{
+       char command[100];
+       bool go = false;
+
+       while (!go) {
+               char *p1 = NULL;
+               if (fgets(command, sizeof(command), stdin) == NULL) {
+                       if (!feof(stdin))
+                           perror("Command read");
+                       exit(1);
+               }
+               if (sscanf(command, "dtr %ms", &p1) == 1)
+                       pulse(fd, dtr_rts_arg('d', p1), 0);
+               else if (sscanf(command, "rts %ms", &p1) == 1)
+                       pulse(fd, 0, dtr_rts_arg('r', p1));
+               else if (strcmp(command, "go\n") == 0)
+                       break;
+               else {
+                       fprintf(stderr, "Unknown command: %s\n", command);
+                       exit(1);
+               }
+
+               free(p1);
+       }
+}
+
 int main(int argc, char *argv[])
 {
        int fd;
@@ -167,18 +196,20 @@ int main(int argc, char *argv[])
        struct termios tio;
        bool stdin_tty;
        bool raw = true;
+       bool cmd = false;
 
        if ((stdin_tty = isatty(0))) {
                CHECK(tcgetattr(0, &stdin_tio_backup));
                atexit(restore_stdin_term);
        }
 
-       while ((opt = getopt(argc, argv, "nd::er::s:v")) != -1) {
+       while ((opt = getopt(argc, argv, "cnd::er::s:v")) != -1) {
                switch (opt) {
-               case 'd': dtr = dtr_rts_arg(opt); break;
+               case 'c': cmd = true; break;
+               case 'd': dtr = dtr_rts_arg(opt, optarg); break;
                case 'e': exit_on_escape = false; break;
                case 'n': raw = false; break;
-               case 'r': rts = dtr_rts_arg(opt); break;
+               case 'r': rts = dtr_rts_arg(opt, optarg); break;
                case 's': {
                        int s = atoi(optarg);
                        switch (s) {
@@ -275,6 +306,11 @@ int main(int argc, char *argv[])
                exit(1);
        }
 
+       VERBOSE("Connected.\r\n");
+
+       if (cmd)
+               handle_commands(fd);
+
        struct pollfd fds[2] = {
                { .fd = 0,  .events = POLLIN },
                { .fd = fd, .events = POLLIN },
@@ -288,7 +324,6 @@ int main(int argc, char *argv[])
                CHECK(tcsetattr(0, TCSANOW, &tio));
        }
 
-       VERBOSE("Connected.\r\n");
        if (exit_on_escape)
                VERBOSE("Use '<Enter>~.' sequence to exit.\r\n");