busybox/loadkmap.c

/* vi: set sw=4 ts=4: */
/*
 * Mini loadkmap implementation for busybox
 *
 * Copyright (C) 1998 Enrique Zanardi <ezanardi@ull.es>
 *
 * 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
 * (at your option) 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include "busybox.h"

#define BINARY_KEYMAP_MAGIC "bkeymap"

/* From <linux/kd.h> */
struct kbentry {
	unsigned char kb_table;
	unsigned char kb_index;
	unsigned short kb_value;
};
static const int KDSKBENT = 0x4B47;  /* sets one entry in translation table */

/* From <linux/keyboard.h> */
static const int NR_KEYS = 128;
static const int MAX_NR_KEYMAPS = 256;

int loadkmap_main(int argc, char **argv)
{
	struct kbentry ke;
	u_short *ibuff;
	int i, j, fd, readsz, pos, ibuffsz = NR_KEYS * sizeof(u_short);
	char flags[MAX_NR_KEYMAPS], buff[7];

	if (argc != 1)
		show_usage();

	fd = open(CURRENT_VC, O_RDWR);
	if (fd < 0)
		perror_msg_and_die("Error opening " CURRENT_VC);

	read(0, buff, 7);
	if (0 != strncmp(buff, BINARY_KEYMAP_MAGIC, 7))
		error_msg_and_die("This is not a valid binary keymap.");

	if (MAX_NR_KEYMAPS != read(0, flags, MAX_NR_KEYMAPS))
		perror_msg_and_die("Error reading keymap flags");

	ibuff = (u_short *) xmalloc(ibuffsz);

	for (i = 0; i < MAX_NR_KEYMAPS; i++) {
		if (flags[i] == 1) {
			pos = 0;
			while (pos < ibuffsz) {
				if ((readsz = read(0, (char *) ibuff + pos, ibuffsz - pos)) < 0)
					perror_msg_and_die("Error reading keymap");
				pos += readsz;
			}
			for (j = 0; j < NR_KEYS; j++) {
				ke.kb_index = j;
				ke.kb_table = i;
				ke.kb_value = ibuff[j];
				ioctl(fd, KDSKBENT, &ke);
			}
		}
	}
	/* Don't bother to close files.  Exit does that 
	 * automagically, so we can save a few bytes */
	/* close(fd); */
	return EXIT_SUCCESS;
}