/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * cmdline.c: Kernel command line creation using ARCS argc/argv.
 *
 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
 */
#include <linux/bug.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>

#include <asm/sgialib.h>
#include <asm/bootinfo.h>

#undef DEBUG_CMDLINE

/*
 * A 32-bit ARC PROM pass arguments and environment as 32-bit pointer.
 * These macro take care of sign extension.
 */
#define prom_argv(index) ((char *) (long)argv[(index)])

static char *ignored[] = {
        "ConsoleIn=",
        "ConsoleOut=",
        "SystemPartition=",
        "OSLoader=",
        "OSLoadPartition=",
        "OSLoadFilename=",
        "OSLoadOptions="
};

static char *used_arc[][2] = {
        { "OSLoadPartition=", "root=" },
        { "OSLoadOptions=", "" }
};

static char __init *move_firmware_args(int argc, LONG *argv, char *cp)
{
        char *s;
        int actr, i;
        size_t len;

        actr = 1; /* Always ignore argv[0] */

        while (actr < argc) {
                for (i = 0; i < ARRAY_SIZE(used_arc); i++) {
                        len = strlen(used_arc[i][0]);

                        if (!strncmp(prom_argv(actr), used_arc[i][0], len)) {
                        /* Ok, we want it. First append the replacement... */
                                strcat(cp, used_arc[i][1]);
                                cp += strlen(used_arc[i][1]);
                                /* ... and now the argument */
                                s = strchr(prom_argv(actr), '=');
                                if (s) {
                                        s++;
                                        len = strlen(s);
                                        memcpy(cp, s, len + 1);
                                        cp += len;
                                }
                                *cp++ = ' ';
                                break;
                        }
                }
                actr++;
        }

        return cp;
}

void __init prom_init_cmdline(int argc, LONG *argv)
{
        char *cp;
        int actr, i;
        size_t len;

        actr = 1; /* Always ignore argv[0] */

        cp = arcs_cmdline;
        /*
         * Move ARC variables to the beginning to make sure they can be
         * overridden by later arguments.
         */
        cp = move_firmware_args(argc, argv, cp);

        while (actr < argc) {
                for (i = 0; i < ARRAY_SIZE(ignored); i++) {
                        len = strlen(ignored[i]);
                        if (!strncmp(prom_argv(actr), ignored[i], len))
                                goto pic_cont;
                }

                /* Ok, we want it. */
                len = strlen(prom_argv(actr));
                memcpy(cp, prom_argv(actr), len + 1);
                cp += len;
                *cp++ = ' ';

        pic_cont:
                actr++;
        }

        if (cp != arcs_cmdline)         /* get rid of trailing space */
                --cp;
        *cp = '\0';

#ifdef DEBUG_CMDLINE
        pr_debug("prom cmdline: %s\n", arcs_cmdline);
#endif
}