xref: /openbmc/u-boot/cmd/terminal.c (revision 8ee59472)
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(cmd_tbl_t * 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 );
76