kbdmapcmd.c for syslinux (load keyboard map and run command)

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2011 Mariano Street
 *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
 *   Copyright 2009 Erwan Velu - All Rights Reserved
 *
 *   This file is based on kbdmap.c and ifcpu.c.
 *
 *   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 3 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, see <http://www.gnu.org/licenses/>.
 *
 * ----------------------------------------------------------------------- */

#include <alloca.h>
#include <stdio.h>
#include <string.h>
#include <console.h>
#include <syslinux/boot.h>
#include <syslinux/loadfile.h>
#include <syslinux/keyboard.h>

static inline void error(const char *msg)
{
    fputs(msg, stderr);
}

static inline int load_keymap(char *file)
{
    const struct syslinux_keyboard_map *const kmap = syslinux_keyboard_map();
    size_t map_size;
    void *kbdmap;

    if (kmap->version != 1) {
        error("Syslinux core version mismatch\n");
        return 1;
    }

    if (loadfile(file, &kbdmap, &map_size)) {
        error("Keyboard map file load error\n");
        return 1;
    }

    if (map_size != kmap->length) {
        error("Keyboard map file format error\n");
        return 1;
    }

    memcpy(kmap->map, kbdmap, map_size);
    return 0;
}

inline static void boot_args(char **args)
{
    // Join strings from an array into a single string.
    int len = 0, a = 0;
    char **pp;
    const char *p;
    char c, *q, *str;

    for (pp = args; *pp; pp++)
        len += strlen(*pp) + 1;

    q = str = alloca(len);
    for (pp = args; *pp; pp++) {
        p = *pp;
        while (c = *p++)
            *q++ = c;
        *q++ = ' ';
        a = 1;
    }
    q -= a;
    *q = '\0';

    if (!str[0])
        syslinux_run_default();
    else
        syslinux_run_command(str);
}

int main(int argc, char *argv[])
{
    openconsole(&dev_null_r, &dev_stdcon_w);

    if (argc < 3) {
    error("Usage: kbdmap <mapfile> <command> [<command parameters>]\n");
    return 1;
    }

    if (load_keymap(argv[1]) == 1)
        return 1;

    boot_args(&argv[2]);
    return 0;
}