opengnsys_ipxe/src/core/keymap.c

94 lines
2.4 KiB
C

/*
* Copyright (C) 2022 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <ctype.h>
#include <ipxe/keys.h>
#include <ipxe/keymap.h>
/** @file
*
* Keyboard mappings
*
*/
/** ASCII character mask */
#define ASCII_MASK 0x7f
/** Control character mask */
#define CTRL_MASK 0x1f
/** Upper case character mask */
#define UPPER_MASK 0x5f
/** Case toggle bit */
#define CASE_TOGGLE ( ASCII_MASK & ~UPPER_MASK )
/** Default keyboard mapping */
static TABLE_START ( keymap_start, KEYMAP );
/** Current keyboard mapping */
static struct keymap *keymap = keymap_start;
/**
* Remap a key
*
* @v character Character read from console
* @ret mapped Mapped character
*/
unsigned int key_remap ( unsigned int character ) {
unsigned int mapped = ( character & KEYMAP_MASK );
struct keymap_key *key;
/* Invert case before remapping if applicable */
if ( ( character & KEYMAP_CAPSLOCK_UNDO ) && isalpha ( mapped ) )
mapped ^= CASE_TOGGLE;
/* Select remapping table */
key = ( ( character & KEYMAP_ALTGR ) ? keymap->altgr : keymap->basic );
/* Remap via table */
for ( ; key->from ; key++ ) {
if ( mapped == key->from ) {
mapped = key->to;
break;
}
}
/* Handle Ctrl-<key> and CapsLock */
if ( isalpha ( mapped ) ) {
if ( character & KEYMAP_CTRL ) {
mapped &= CTRL_MASK;
} else if ( character & KEYMAP_CAPSLOCK ) {
mapped ^= CASE_TOGGLE;
}
}
/* Clear flags */
mapped &= ASCII_MASK;
DBGC2 ( &keymap, "KEYMAP mapped %04x => %02x\n", character, mapped );
return mapped;
}