sun4v/promif/promif_reboot.c

	promif_reboot.c revision 1ae0874509b6811fdde1dfd46f0d93fd09867a3f
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/promif_impl.h>
#include <sys/hypervisor_api.h>

/*
 * Reboot Command String
 *
 * The prom_reboot() CIF handler takes an optional string containing
 * arguments to the boot command that are to be applied to the reboot.
 * This information is used to create a full boot command string that
 * is stored in a well known ldom variable (REBOOT_CMD_VAR_NAME). The
 * string is constructed to take the following form:
 *
 *  boot <specified boot arguments><NULL>
 *
 * When the domain comes back up, OBP consults this variable. If set,
 * it will use the unmodified boot command string to boot the domain.
 * The maximum length of the boot command is specified by the constant
 * REBOOT_CMD_MAX_LEN. If the specified arguments cause the command
 * string to exceed this length, the arguments are truncated.
 */
#define REBOOT_CMD_VAR_NAME     "reboot-command"
#define REBOOT_CMD_BASE         "boot "
#define REBOOT_CMD_MAX_LEN      256
#define REBOOT_CMD_ARGS_MAX_LEN     (REBOOT_CMD_MAX_LEN -       \
                    prom_strlen(REBOOT_CMD_BASE) - 1)
int
promif_reboot(void *p)
{
    cell_t  *ci = (cell_t *)p;
    int rv = 0;
#ifndef _KMDB
    char    *bootargs;
    char    bootcmd[REBOOT_CMD_MAX_LEN];
    char    *cmd_end;
    int cmd_len;
#endif

    /* one argument expected */
    ASSERT(ci[1] == 1);

#ifndef _KMDB
    bootargs = p1275_cell2ptr(ci[3]);

    if (bootargs == NULL)
        bootargs = "";

    /* verify the length of the command string */
    cmd_len = prom_strlen(REBOOT_CMD_BASE) + prom_strlen(bootargs) + 1;

    if (cmd_len > REBOOT_CMD_MAX_LEN) {
        /*
         * Unable to set the requested boot arguments.
         * Truncate them so that the boot command will
         * fit within the maximum length. This follows
         * the policy also used by OBP.
         */
        cmd_end = bootargs + REBOOT_CMD_ARGS_MAX_LEN;
        *cmd_end = '\0';

        prom_printf("WARNING: reboot command length (%d) too long, "
            "truncating command arguments\n", cmd_len);
    }

    /* construct the boot command string */
    (void) prom_sprintf(bootcmd, "%s%s", REBOOT_CMD_BASE, bootargs);

    cmd_len = prom_strlen(bootcmd) + 1;
    ASSERT(cmd_len <= REBOOT_CMD_MAX_LEN);

    CIF_DBG_REBOOT("bootcmd='%s'\n", bootcmd);

    /* attempt to set the ldom variable */
    if (promif_ldom_setprop(REBOOT_CMD_VAR_NAME, bootcmd, cmd_len) == -1) {
        prom_printf("WARNING: unable to store boot command for "
            "use on reboot\n");
    }
#endif

    prom_printf("Resetting...\n");

    rv = hv_mach_sir();

    /* should not return */
    ASSERT(0);

    return (rv);
}