prom_heartbeat.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (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 (c) 1994, by Sun Microsystems, Inc.
* All rights reserved.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/promif.h>
#include <sys/promimpl.h>
/*
* Provide 10 millisecond heartbeat for the PROM. A client that has taken over
* the trap table and clock interrupts, but is not quite ready to take over the
* function of polling the input-device for an abort sequence (L1/A or BREAK)
* may use this function to instruct the PROM to poll the keyboard. If used,
* this function should be called every 10 milliseconds.
*/
int
prom_heartbeat(int msecs)
{
cell_t ci[5];
ci[0] = p1275_ptr2cell("SUNW,heartbeat"); /* Service name */
ci[1] = (cell_t)1; /* #argument cells */
ci[2] = (cell_t)1; /* #result cells */
ci[3] = p1275_int2cell(msecs); /* Arg1: msecs */
ci[4] = (cell_t)0; /* Prime the result */
promif_preprom();
(void) p1275_cif_handler(&ci);
promif_postprom();
return (p1275_cell2int(ci[4])); /* Res1: abort-flag */
}