/**************************************************************************** * apps/nshlib/nsh_altconsole.c * * Copyright (C) 2018 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * Author: Alan Carvalho de Assis * * 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 NuttX 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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include "nsh.h" #include "nsh_console.h" #if defined(CONFIG_NSH_ALTCONDEV) && !defined(HAVE_USB_CONSOLE) /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: nsh_clone_console * * Description: * Clone stdout and stderr to alternatives devices * ****************************************************************************/ static int nsh_clone_console(FAR struct console_stdio_s *pstate) { int fd; /* Open the alternative standard error device */ fd = open(CONFIG_NSH_ALTSTDERR, O_WRONLY); if (fd < 0) { return -ENODEV; } /* Close stderr: note we only close stderr if we opened the alternative one */ fclose(stderr); /* Associate the new opened file descriptor to stderr */ dup2(fd, 2); /* Close the console device that we just opened */ if (fd != 0) { close(fd); } /* Open the alternative standard output device */ fd = open(CONFIG_NSH_ALTSTDOUT, O_WRONLY); if (fd < 0) { return -ENODEV; } /* Close stdout: note we only close stdout if we opened the alternative one */ fclose(stdout); /* Associate the new opened file descriptor to stdout */ dup2(fd, 1); /* Close the console device that we just opened */ if (fd != 0) { close(fd); } /* Setup the stderr */ pstate->cn_errfd = 2; pstate->cn_errstream = fdopen(pstate->cn_errfd, "a"); if (!pstate->cn_errstream) { close(pstate->cn_errfd); free(pstate); return -EIO; } /* Setup the stdout */ pstate->cn_outfd = 1; pstate->cn_outstream = fdopen(pstate->cn_outfd, "a"); if (!pstate->cn_outstream) { close(pstate->cn_outfd); free(pstate); return -EIO; } return OK; } /**************************************************************************** * Name: nsh_wait_inputdev * * Description: * Wait for the input device to be ready * ****************************************************************************/ static int nsh_wait_inputdev(FAR struct console_stdio_s *pstate, FAR const char *msg) { int fd; /* Don't start the NSH console until the input device is ready. Chances * are, we get here with no functional stdin. For example a USB keyboard * device will not be available until the device is connected to the host * and enumerated. */ /* Open the USB keyboard device for read-only access */ do { /* Try to open the alternative stdin device */ fd = open(CONFIG_NSH_ALTSTDIN, O_RDWR); if (fd < 0) { #ifdef CONFIG_DEBUG_FEATURES int errcode = errno; /* ENOENT means that the USB device is not yet connected and, * hence, has no entry under /dev. If the USB driver still * exists under /dev (because other threads still have the driver * open), then we might also get ENODEV. Anything else would * be really bad. */ DEBUGASSERT(errcode == ENOENT || errcode == ENODEV); #endif /* Let the user know that we are waiting */ if (msg) { /* Show the waiting message only one time after the failure * to open the keyboard device. */ puts(msg); fflush(stdout); msg = NULL; } /* Sleep a bit and try again */ sleep(2); } } while (fd < 0); /* Close stdin: note we only closed stdin if we opened the alternative one */ fclose(stdin); /* Okay.. we have successfully opened the input device. Did * we just re-open fd 0? */ if (fd != 0) { /* No.. Dup the fd to create standard fd 0. stdin should not know. */ dup2(fd, 0); /* Setup the input console */ pstate->cn_confd = 0; /* Create a standard C stream on the console device */ pstate->cn_constream = fdopen(pstate->cn_confd, "r+"); if (!pstate->cn_constream) { close(pstate->cn_confd); free(pstate); return -EIO; } /* Close the input device that we just opened */ close(fd); } return OK; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: nsh_consolemain (USB console version) * * Description: * This interfaces maybe to called or started with task_start to start a * single an NSH instance that operates on stdin and stdout. This * function does not return. * * This function handles generic /dev/console character devices for output * but uses a special USB keyboard device for input. The USB keyboard * requires some special operations to handle the cases where the session * input is lost when the USB keyboard is unplugged and restarted when the * USB keyboard is plugged in again. * * Input Parameters: * Standard task start-up arguments. These are not used. argc may be * zero and argv may be NULL. * * Returned Values: * This function does not return nor does it ever exit (unless the user * executes the NSH exit command). * ****************************************************************************/ int nsh_consolemain(int argc, char *argv[]) { FAR struct console_stdio_s *pstate = nsh_newconsole(); FAR const char *msg; int ret; DEBUGASSERT(pstate); /* Initialize any USB tracing options that were requested */ #ifdef CONFIG_NSH_USBDEV_TRACE usbtrace_enable(TRACE_BITSET); #endif /* Execute the one-time start-up script. Any output will go to /dev/console. */ #ifdef CONFIG_NSH_ROMFSETC nsh_initscript(&pstate->cn_vtbl); #endif #if defined(CONFIG_NSH_ARCHINIT) && defined(CONFIG_BOARDCTL_FINALINIT) /* Perform architecture-specific final-initialization (if configured) */ boardctl(BOARDIOC_FINALINIT, 0); #endif /* First map stderr and stdout to alternative devices */ ret = nsh_clone_console(pstate); if (ret < 0) { return ret; } /* Now loop, executing creating a session for each USB connection */ msg = "Waiting for a keyboard...\n"; for (; ; ) { /* Wait for the USB to be connected to the host and switch * standard I/O to the USB serial device. */ ret = nsh_wait_inputdev(pstate, msg); DEBUGASSERT(ret == OK); UNUSED(ret); /* Execute the session */ nsh_session(pstate); /* We lost the connection. Wait for the keyboard to * be re-connected. */ msg = "Please re-connect the keyboard...\n"; } } #endif /* HAVE_USB_KEYBOARD && !HAVE_USB_CONSOLE */