Porting BSD console screensavers to Linux

From: Tony Rowe
Date: Tue Jun 20 2006 - 10:39:38 EST


Hello,

I have been wondering about this for a few years. Are there any
[non-locking] screensavers for the Linux console like 'warp_saver' which
is implemented in the BSD kernel I think? Could the BSD syscons
screensavers be implemented in the Linux kernel? The warp_saver.c is
included below.

Thanks for all the good work,
Tony Rowe

modules/syscons/warp/warp_saver.c

http://freebsd.active-venture.com/FreeBSD-srctree/newsrc/modules/syscons/warp/warp_saver.c.html

/*-
* Copyright (c) 1998 Dag-Erling Coïdan Smørgrav
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD: src/sys/modules/syscons/warp/warp_saver.c,v 1.7.2.1 2000/05/10 16:
26:47 obrien Exp $
*/

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/syslog.h>
#include <sys/consio.h>
#include <sys/fbio.h>
#include <sys/random.h>

#include <dev/fb/fbreg.h>
#include <dev/fb/splashreg.h>
#include <dev/syscons/syscons.h>

static u_char *vid;
static int blanked;

#define SCRW 320
#define SCRH 200
#define SPP 15
#define STARS (SPP*(1+2+4+8))

static int star[STARS];
static u_char warp_pal[768] = {
0x00, 0x00, 0x00,
0x66, 0x66, 0x66,
0x99, 0x99, 0x99,
0xcc, 0xcc, 0xcc,
0xff, 0xff, 0xff
/* the rest is zero-filled by the compiler */
};

static void
warp_update(void)
{
int i, j, k, n;

for (i = 1, k = 0, n = SPP*8; i < 5; i++, n /= 2)
for (j = 0; j < n; j++, k++) {
vid[star[k]] = 0;
star[k] += i;
if (star[k] > SCRW*SCRH)
star[k] -= SCRW*SCRH;
vid[star[k]] = i;
}
}

static int
warp_saver(video_adapter_t *adp, int blank)
{
int pl;

if (blank) {
/* switch to graphics mode */
if (blanked <= 0) {
pl = splhigh();
set_video_mode(adp, M_VGA_CG320);
load_palette(adp, warp_pal);
#if 0 /* XXX conflict */
set_border(adp, 0);
#endif
blanked++;
vid = (u_char *)adp->va_window;
splx(pl);
bzero(vid, SCRW*SCRH);
}

/* update display */
warp_update();

} else {
blanked = 0;
}
return 0;
}

static int
warp_init(video_adapter_t *adp)
{
video_info_t info;
int i;

/* check that the console is capable of running in 320x200x256 */
if (get_mode_info(adp, M_VGA_CG320, &info)) {
log(LOG_NOTICE, "warp_saver: the console does not support M_VGA_CG320\n
");
return ENODEV;
}

/* randomize the star field */
for (i = 0; i < STARS; i++) {
star[i] = random() % (SCRW*SCRH);
}

blanked = 0;

return 0;
}

static int
warp_term(video_adapter_t *adp)
{
return 0;
}

static scrn_saver_t warp_module = {
"warp_saver", warp_init, warp_term, warp_saver, NULL,



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