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author | Andrew Tridgell <tridge@samba.org> | 2013-08-03 18:54:03 +1000 |
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committer | Lorenz Meier <lm@inf.ethz.ch> | 2013-08-03 11:41:35 +0200 |
commit | 4708693f86858772e88d7736a4996023d4f57327 (patch) | |
tree | cb26d02f682a27582acf664ff0518fd77e59f9f6 /src/systemcmds/nshterm/nshterm.c | |
parent | ecc7bc5bca40e9d5e0a7271105dea9b3441af0a8 (diff) | |
download | px4-firmware-4708693f86858772e88d7736a4996023d4f57327.tar.gz px4-firmware-4708693f86858772e88d7736a4996023d4f57327.tar.bz2 px4-firmware-4708693f86858772e88d7736a4996023d4f57327.zip |
nshterm: start a nsh console on any device
this is used in APM startup to fallback to a console on ttyACM0 if
startup fails for any reason
Diffstat (limited to 'src/systemcmds/nshterm/nshterm.c')
-rw-r--r-- | src/systemcmds/nshterm/nshterm.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/src/systemcmds/nshterm/nshterm.c b/src/systemcmds/nshterm/nshterm.c new file mode 100644 index 000000000..bde0e7841 --- /dev/null +++ b/src/systemcmds/nshterm/nshterm.c @@ -0,0 +1,90 @@ +/**************************************************************************** + * + * Copyright (c) 2012, 2013 PX4 Development Team. All rights reserved. + * Author: Andrew Tridgell + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name PX4 nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/** + * @file nshterm.c + * start a nsh terminal on a given port. This can be useful for error + * handling in startup scripts to start a nsh shell on /dev/ttyACM0 + * for diagnostics + */ + +#include <nuttx/config.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdarg.h> +#include <unistd.h> +#include <stdlib.h> +#include <errno.h> +#include <apps/nsh.h> +#include <fcntl.h> + +__EXPORT int nshterm_main(int argc, char *argv[]); + +int +nshterm_main(int argc, char *argv[]) +{ + if (argc < 2) { + printf("Usage: nshterm <device>\n"); + exit(1); + } + uint8_t retries = 0; + int fd = -1; + while (retries < 5) { + // the retries are to cope with the behaviour of /dev/ttyACM0 + // which may not be ready immediately. + fd = open(argv[1], O_RDWR); + if (fd != -1) { + break; + } + usleep(100000); + retries++; + } + if (fd == -1) { + perror(argv[1]); + exit(1); + } + // setup standard file descriptors + close(0); + close(1); + close(2); + dup2(fd, 0); + dup2(fd, 1); + dup2(fd, 2); + + nsh_consolemain(0, NULL); + + close(fd); + + return OK; +} |