1 /*
2 * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19 FILE_LICENCE ( GPL2_OR_LATER );
20
21 #include <ctype.h>
22 #include <console.h>
23 #include <gpxe/process.h>
24 #include <gpxe/keys.h>
25 #include <gpxe/timer.h>
26
27 /** @file
28 *
29 * Special key interpretation
30 *
31 */
32
33 #define GETKEY_TIMEOUT ( TICKS_PER_SEC / 4 )
34
35 /**
36 * Read character from console if available within timeout period
37 *
38 * @v timeout Timeout period, in ticks
39 * @ret character Character read from console
40 */
getchar_timeout(unsigned long timeout)41 static int getchar_timeout ( unsigned long timeout ) {
42 unsigned long expiry = ( currticks() + timeout );
43
44 while ( currticks() < expiry ) {
45 step();
46 if ( iskey() )
47 return getchar();
48 }
49
50 return -1;
51 }
52
53 /**
54 * Get single keypress
55 *
56 * @ret key Key pressed
57 *
58 * The returned key will be an ASCII value or a KEY_XXX special
59 * constant. This function differs from getchar() in that getchar()
60 * will return "special" keys (e.g. cursor keys) as a series of
61 * characters forming an ANSI escape sequence.
62 */
getkey(void)63 int getkey ( void ) {
64 int character;
65 unsigned int n = 0;
66
67 character = getchar();
68 if ( character != ESC )
69 return character;
70
71 while ( ( character = getchar_timeout ( GETKEY_TIMEOUT ) ) >= 0 ) {
72 if ( character == '[' )
73 continue;
74 if ( isdigit ( character ) ) {
75 n = ( ( n * 10 ) + ( character - '0' ) );
76 continue;
77 }
78 if ( character >= 0x40 )
79 return KEY_ANSI ( n, character );
80 }
81
82 return ESC;
83 }
84