cmd/terminal.c

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