cmd/terminal.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2007 OpenMoko, Inc.
   4  * Written by Harald Welte <laforge@openmoko.org>
   5  */
   6
   7 /*
   8  * Boot support
   9  */
  10 #include <common.h>
  11 #include <command.h>
  12 #include <stdio_dev.h>
  13 #include <serial.h>
  14
  15 int do_terminal(struct cmd_tbl *cmd, int flag, int argc, char *const argv[])
  16 {
  17         int last_tilde = 0;
  18         struct stdio_dev *dev = NULL;
  19
  20         if (argc < 1)
  21                 return -1;
  22
  23         /* Scan for selected output/input device */
  24         dev = stdio_get_by_name(argv[1]);
  25         if (!dev)
  26                 return -1;
  27
  28         if (IS_ENABLED(CONFIG_SERIAL))
  29                 serial_reinit_all();
  30
  31         printf("Entering terminal mode for port %s\n", dev->name);
  32         puts("Use '~.' to leave the terminal and get back to u-boot\n");
  33
  34         while (1) {
  35                 int c;
  36
  37                 /* read from console and display on serial port */
  38                 if (stdio_devices[0]->tstc(stdio_devices[0])) {
  39                         c = stdio_devices[0]->getc(stdio_devices[0]);
  40                         if (last_tilde == 1) {
  41                                 if (c == '.') {
  42                                         putc(c);
  43                                         putc('\n');
  44                                         break;
  45                                 } else {
  46                                         last_tilde = 0;
  47                                         /* write the delayed tilde */
  48                                         dev->putc(dev, '~');
  49                                         /* fall-through to print current
  50                                          * character */
  51                                 }
  52                         }
  53                         if (c == '~') {
  54                                 last_tilde = 1;
  55                                 puts("[u-boot]");
  56                                 putc(c);
  57                         }
  58                         dev->putc(dev, c);
  59                 }
  60
  61                 /* read from serial port and display on console */
  62                 if (dev->tstc(dev)) {
  63                         c = dev->getc(dev);
  64                         putc(c);
  65                 }
  66         }
  67         return 0;
  68 }
  69
  70
  71 /***************************************************/
  72
  73 U_BOOT_CMD(
  74         terminal,       3,      1,      do_terminal,
  75         "start terminal emulator",
  76         ""
  77 );