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         serial_reinit_all();
  29         printf("Entering terminal mode for port %s\n", dev->name);
  30         puts("Use '~.' to leave the terminal and get back to u-boot\n");
  31
  32         while (1) {
  33                 int c;
  34
  35                 /* read from console and display on serial port */
  36                 if (stdio_devices[0]->tstc()) {
  37                         c = stdio_devices[0]->getc();
  38                         if (last_tilde == 1) {
  39                                 if (c == '.') {
  40                                         putc(c);
  41                                         putc('\n');
  42                                         break;
  43                                 } else {
  44                                         last_tilde = 0;
  45                                         /* write the delayed tilde */
  46                                         dev->putc('~');
  47                                         /* fall-through to print current
  48                                          * character */
  49                                 }
  50                         }
  51                         if (c == '~') {
  52                                 last_tilde = 1;
  53                                 puts("[u-boot]");
  54                                 putc(c);
  55                         }
  56                         dev->putc(c);
  57                 }
  58
  59                 /* read from serial port and display on console */
  60                 if (dev->tstc()) {
  61                         c = dev->getc();
  62                         putc(c);
  63                 }
  64         }
  65         return 0;
  66 }
  67
  68
  69 /***************************************************/
  70
  71 U_BOOT_CMD(
  72         terminal,       3,      1,      do_terminal,
  73         "start terminal emulator",
  74         ""
  75 );