fbset.c - fp2-dev/platform/external/busybox - Gitiles

 /* vi: set sw=4 ts=4: */
 /*
  * Mini fbset implementation for busybox
  *
  * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
  *
  * 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 2 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, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  *
  * This is a from-scratch implementation of fbset; but the de facto fbset
  * implementation was a good reference. fbset (original) is released under
  * the GPL, and is (c) 1995-1999 by:
  *     Geert Uytterhoeven (Geert.Uytterhoeven@cs.kuleuven.ac.be)
  */

 #include "busybox.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <errno.h>
 #include <ctype.h>
 #include <sys/ioctl.h>

 #define PERROR(ctx)   do { perror(ctx); exit(1); } while(0)

 #define DEFAULTFBDEV  "/dev/fb0"
 #define DEFAULTFBMODE "/etc/fb.modes"

 #define OPT_CHANGE    1
 #define OPT_INFO      (1 << 1)
 #define OPT_READMODE  (1 << 2)

 #define CMD_HELP        0
 #define CMD_FB		1
 #define CMD_DB		2
 #define CMD_GEOMETRY	3
 #define CMD_TIMING	4
 #define CMD_ACCEL	5
 #define CMD_HSYNC	6
 #define CMD_VSYNC	7
 #define CMD_LACED	8
 #define CMD_DOUBLE	9
 /* #define CMD_XCOMPAT     10 */
 #define CMD_ALL         11
 #define CMD_INFO        12
 #define CMD_CHANGE      13

 #ifdef BB_FEATURE_FBSET_FANCY
 #define CMD_XRES	100
 #define CMD_YRES	101
 #define CMD_VXRES	102
 #define CMD_VYRES	103
 #define CMD_DEPTH	104
 #define CMD_MATCH	105
 #define CMD_PIXCLOCK	106
 #define CMD_LEFT	107
 #define CMD_RIGHT	108
 #define CMD_UPPER	109
 #define CMD_LOWER	110
 #define CMD_HSLEN	111
 #define CMD_VSLEN	112
 #define CMD_CSYNC	113
 #define CMD_GSYNC	114
 #define CMD_EXTSYNC	115
 #define CMD_BCAST	116
 #define CMD_RGBA	117
 #define CMD_STEP	118
 #define CMD_MOVE	119
 #endif

 static unsigned int g_options = 0;

 /* Stuff stolen from the kernel's fb.h */
 #define FBIOGET_VSCREENINFO     0x4600
 #define FBIOPUT_VSCREENINFO     0x4601
 #define __u32			unsigned int
 struct fb_bitfield {
 	__u32 offset;			/* beginning of bitfield	*/
 	__u32 length;			/* length of bitfield		*/
 	__u32 msb_right;		/* != 0 : Most significant bit is */
 					/* right */
 };
 struct fb_var_screeninfo {
 	__u32 xres;			/* visible resolution		*/
 	__u32 yres;
 	__u32 xres_virtual;		/* virtual resolution		*/
 	__u32 yres_virtual;
 	__u32 xoffset;			/* offset from virtual to visible */
 	__u32 yoffset;			/* resolution			*/

 	__u32 bits_per_pixel;		/* guess what			*/
 	__u32 grayscale;		/* != 0 Graylevels instead of colors */

 	struct fb_bitfield red;		/* bitfield in fb mem if true color, */
 	struct fb_bitfield green;	/* else only length is significant */
 	struct fb_bitfield blue;
 	struct fb_bitfield transp;	/* transparency			*/

 	__u32 nonstd;			/* != 0 Non standard pixel format */

 	__u32 activate;			/* see FB_ACTIVATE_*		*/

 	__u32 height;			/* height of picture in mm    */
 	__u32 width;			/* width of picture in mm     */

 	__u32 accel_flags;		/* acceleration flags (hints)	*/

 	/* Timing: All values in pixclocks, except pixclock (of course) */
 	__u32 pixclock;			/* pixel clock in ps (pico seconds) */
 	__u32 left_margin;		/* time from sync to picture	*/
 	__u32 right_margin;		/* time from picture to sync	*/
 	__u32 upper_margin;		/* time from sync to picture	*/
 	__u32 lower_margin;
 	__u32 hsync_len;		/* length of horizontal sync	*/
 	__u32 vsync_len;		/* length of vertical sync	*/
 	__u32 sync;			/* see FB_SYNC_*		*/
 	__u32 vmode;			/* see FB_VMODE_*		*/
 	__u32 reserved[6];		/* Reserved for future compatibility */
 };


 struct cmdoptions_t {
 	char *name;
 	unsigned char param_count;
 	unsigned char code;
 } g_cmdoptions[] = {
 	{
 	"-h", 0, CMD_HELP}, {
 	"-fb", 1, CMD_FB}, {
 	"-db", 1, CMD_DB}, {
 	"-a", 0, CMD_ALL}, {
 	"-i", 0, CMD_INFO}, {
 	"-g", 5, CMD_GEOMETRY}, {
 	"-t", 7, CMD_TIMING}, {
 	"-accel", 1, CMD_ACCEL}, {
 	"-hsync", 1, CMD_HSYNC}, {
 	"-vsync", 1, CMD_VSYNC}, {
 	"-laced", 1, CMD_LACED}, {
 	"-double", 1, CMD_DOUBLE}, {
 	"-help", 0, CMD_HELP}, {
 	"-n", 0, CMD_CHANGE}, {
 #ifdef BB_FEATURE_FBSET_FANCY
 	"-help", 0, CMD_HELP}, {
 	"-all", 0, CMD_ALL}, {
 	"-xres", 1, CMD_XRES}, {
 	"-yres", 1, CMD_YRES}, {
 	"-vxres", 1, CMD_VXRES}, {
 	"-vyres", 1, CMD_VYRES}, {
 	"-depth", 1, CMD_DEPTH}, {
 	"-match", 0, CMD_MATCH}, {
 	"-geometry", 5, CMD_GEOMETRY}, {
 	"-pixclock", 1, CMD_PIXCLOCK}, {
 	"-left", 1, CMD_LEFT}, {
 	"-right", 1, CMD_RIGHT}, {
 	"-upper", 1, CMD_UPPER}, {
 	"-lower", 1, CMD_LOWER}, {
 	"-hslen", 1, CMD_HSLEN}, {
 	"-vslen", 1, CMD_VSLEN}, {
 	"-timings", 7, CMD_TIMING}, {
 	"-csync", 1, CMD_CSYNC}, {
 	"-gsync", 1, CMD_GSYNC}, {
 	"-extsync", 1, CMD_EXTSYNC}, {
 	"-bcast", 1, CMD_BCAST}, {
 	"-rgba", 1, CMD_RGBA}, {
 	"-step", 1, CMD_STEP}, {
 	"-move", 1, CMD_MOVE}, {
 #endif
 	0, 0, 0}
 };

 #ifdef BB_FEATURE_FBSET_READMODE
 /* taken from linux/fb.h */
 #define FB_VMODE_INTERLACED	1	/* interlaced	*/
 #define FB_VMODE_DOUBLE		2	/* double scan */
 #define FB_SYNC_HOR_HIGH_ACT	1	/* horizontal sync high active	*/
 #define FB_SYNC_VERT_HIGH_ACT	2	/* vertical sync high active	*/
 #define FB_SYNC_EXT		4	/* external sync		*/
 #define FB_SYNC_COMP_HIGH_ACT	8	/* composite sync high active   */
 #endif
 static int readmode(struct fb_var_screeninfo *base, const char *fn,
 					const char *mode)
 {
 #ifdef BB_FEATURE_FBSET_READMODE
 	FILE *f;
 	char buf[256];
 	char *p = buf;

 	if ((f = fopen(fn, "r")) == NULL)
 		PERROR("readmode(fopen)");
 	while (!feof(f)) {
 		fgets(buf, sizeof(buf), f);
 		if ((p = strstr(buf, "mode ")) || (p = strstr(buf, "mode\t"))) {
 			p += 5;
 			if ((p = strstr(buf, mode))) {
 				p += strlen(mode);
 				if (!isspace(*p) && (*p != 0) && (*p != '"')
 					&& (*p != '\r') && (*p != '\n'))
 					continue;	/* almost, but not quite */
 				while (!feof(f)) {
 					fgets(buf, sizeof(buf), f);

                     if ((p = strstr(buf, "geometry "))) {
                         p += 9;

                         sscanf(p, "%d %d %d %d %d",
                                 &(base->xres), &(base->yres),
                                 &(base->xres_virtual), &(base->yres_virtual),
                                 &(base->bits_per_pixel));
                     } else if ((p = strstr(buf, "timings "))) {
                         p += 8;

                         sscanf(p, "%d %d %d %d %d %d %d",
                                 &(base->pixclock),
                                 &(base->left_margin), &(base->right_margin),
                                 &(base->upper_margin), &(base->lower_margin),
                                 &(base->hsync_len), &(base->vsync_len));
                     } else if ((p = strstr(buf, "laced "))) {
                         p += 6;

                         if (strstr(buf, "false")) {
                             base->vmode &= ~FB_VMODE_INTERLACED;
                         } else {
                             base->vmode |= FB_VMODE_INTERLACED;
                         }
                     } else if ((p = strstr(buf, "double "))) {
                         p += 7;

                         if (strstr(buf, "false")) {
                             base->vmode &= ~FB_VMODE_DOUBLE;
                         } else {
                             base->vmode |= FB_VMODE_DOUBLE;
                         }
                     } else if ((p = strstr(buf, "vsync "))) {
                         p += 6;

                         if (strstr(buf, "low")) {
                             base->sync &= ~FB_SYNC_VERT_HIGH_ACT;
                         } else {
                             base->sync |= FB_SYNC_VERT_HIGH_ACT;
                         }
                     } else if ((p = strstr(buf, "hsync "))) {
                         p += 6;

                         if (strstr(buf, "low")) {
                             base->sync &= ~FB_SYNC_HOR_HIGH_ACT;
                         } else {
                             base->sync |= FB_SYNC_HOR_HIGH_ACT;
                         }
                     } else if ((p = strstr(buf, "csync "))) {
                         p += 6;

                         if (strstr(buf, "low")) {
                             base->sync &= ~FB_SYNC_COMP_HIGH_ACT;
                         } else {
                             base->sync |= FB_SYNC_COMP_HIGH_ACT;
                         }
                     } else if ((p = strstr(buf, "extsync "))) {
                         p += 8;

                         if (strstr(buf, "false")) {
                             base->sync &= ~FB_SYNC_EXT;
                         } else {
                             base->sync |= FB_SYNC_EXT;
                         }
                     }

 					if (strstr(buf, "endmode"))
 						return 1;
 				}
 			}
 		}
 	}
 #else
 	error_msg( "mode reading not compiled in\n");
 #endif
 	return 0;
 }

 static void setmode(struct fb_var_screeninfo *base,
 					struct fb_var_screeninfo *set)
 {
 	if ((int) set->xres > 0)
 		base->xres = set->xres;
 	if ((int) set->yres > 0)
 		base->yres = set->yres;
 	if ((int) set->xres_virtual > 0)
 		base->xres_virtual = set->xres_virtual;
 	if ((int) set->yres_virtual > 0)
 		base->yres_virtual = set->yres_virtual;
 	if ((int) set->bits_per_pixel > 0)
 		base->bits_per_pixel = set->bits_per_pixel;
 }

 static void showmode(struct fb_var_screeninfo *v)
 {
 	double drate = 0, hrate = 0, vrate = 0;

 	if (v->pixclock) {
 		drate = 1e12 / v->pixclock;
 		hrate =
 			drate / (v->left_margin + v->xres + v->right_margin +
 					 v->hsync_len);
 		vrate =
 			hrate / (v->upper_margin + v->yres + v->lower_margin +
 					 v->vsync_len);
 	}
 	printf("\nmode \"%ux%u-%u\"\n", v->xres, v->yres, (int) (vrate + 0.5));
 #ifdef BB_FEATURE_FBSET_FANCY
 	printf("\t# D: %.3f MHz, H: %.3f kHz, V: %.3f Hz\n", drate / 1e6,
 		   hrate / 1e3, vrate);
 #endif
 	printf("\tgeometry %u %u %u %u %u\n", v->xres, v->yres,
 		   v->xres_virtual, v->yres_virtual, v->bits_per_pixel);
 	printf("\ttimings %u %u %u %u %u %u %u\n", v->pixclock, v->left_margin,
 		   v->right_margin, v->upper_margin, v->lower_margin, v->hsync_len,
 		   v->vsync_len);
 	printf("\taccel %s\n", (v->accel_flags > 0 ? "true" : "false"));
 	printf("\trgba %u/%u,%u/%u,%u/%u,%u/%u\n", v->red.length,
 		   v->red.offset, v->green.length, v->green.offset, v->blue.length,
 		   v->blue.offset, v->transp.length, v->transp.offset);
 	printf("endmode\n\n");
 }

 static void fbset_usage(void)
 {
 #ifndef BB_FEATURE_TRIVIAL_HELP
 	int i;
 #endif

 #ifndef STANDALONE
 	fprintf(stderr, "BusyBox v%s (%s) multi-call binary -- GPL2\n\n",
 			BB_VER, BB_BT);
 #endif
 	fprintf(stderr, "Usage: fbset [options] [mode]\n");
 #ifndef BB_FEATURE_TRIVIAL_HELP
 	fprintf(stderr, "\nShows and modifies frame buffer device settings\n\n");
 	fprintf(stderr, "The following options are recognized:\n");
 	for (i = 0; g_cmdoptions[i].name; i++)
 		fprintf(stderr, "\t%s\n", g_cmdoptions[i].name);
 #endif
 	exit(-1);
 }

 #ifdef STANDALONE
 int main(int argc, char **argv)
 #else
 extern int fbset_main(int argc, char **argv)
 #endif
 {
 	struct fb_var_screeninfo var, varset;
 	int fh, i;
 	char *fbdev = DEFAULTFBDEV;
 	char *modefile = DEFAULTFBMODE;
 	char *thisarg, *mode = NULL;

 	memset(&varset, 0xFF, sizeof(varset));

 	/* parse cmd args.... why do they have to make things so difficult? */
 	argv++;
 	argc--;
 	for (; argc > 0 && (thisarg = *argv); argc--, argv++) {
 		for (i = 0; g_cmdoptions[i].name; i++) {
 			if (!strcmp(thisarg, g_cmdoptions[i].name)) {
 				if (argc - 1 < g_cmdoptions[i].param_count)
 					fbset_usage();
 				switch (g_cmdoptions[i].code) {
 				case CMD_HELP:
 					fbset_usage();
 				case CMD_FB:
 					fbdev = argv[1];
 					break;
 				case CMD_DB:
 					modefile = argv[1];
 					break;
 				case CMD_GEOMETRY:
 					varset.xres = strtoul(argv[1], 0, 0);
 					varset.yres = strtoul(argv[2], 0, 0);
 					varset.xres_virtual = strtoul(argv[3], 0, 0);
 					varset.yres_virtual = strtoul(argv[4], 0, 0);
 					varset.bits_per_pixel = strtoul(argv[5], 0, 0);
 					break;
 				case CMD_TIMING:
 					varset.pixclock = strtoul(argv[1], 0, 0);
 					varset.left_margin = strtoul(argv[2], 0, 0);
 					varset.right_margin = strtoul(argv[3], 0, 0);
 					varset.upper_margin = strtoul(argv[4], 0, 0);
 					varset.lower_margin = strtoul(argv[5], 0, 0);
 					varset.hsync_len = strtoul(argv[6], 0, 0);
 					varset.vsync_len = strtoul(argv[7], 0, 0);
 					break;
                 case CMD_CHANGE:
                     g_options |= OPT_CHANGE;
                     break;
 #ifdef BB_FEATURE_FBSET_FANCY
 				case CMD_XRES:
 					varset.xres = strtoul(argv[1], 0, 0);
 					break;
 				case CMD_YRES:
 					varset.yres = strtoul(argv[1], 0, 0);
 					break;
 #endif
 				}
 				argc -= g_cmdoptions[i].param_count;
 				argv += g_cmdoptions[i].param_count;
 				break;
 			}
 		}
 		if (!g_cmdoptions[i].name) {
 			if (argc == 1) {
 				mode = *argv;
 				g_options |= OPT_READMODE;
 			} else {
 				fbset_usage();
 			}
 		}
 	}

 	if ((fh = open(fbdev, O_RDONLY)) < 0)
 		PERROR("fbset(open)");
 	if (ioctl(fh, FBIOGET_VSCREENINFO, &var))
 		PERROR("fbset(ioctl)");
 	if (g_options & OPT_READMODE) {
 		if (!readmode(&var, modefile, mode)) {
 			error_msg("Unknown video mode `%s'\n", mode);
 			return EXIT_FAILURE;
 		}
 	}

 	setmode(&var, &varset);
 	if (g_options & OPT_CHANGE)
 		if (ioctl(fh, FBIOPUT_VSCREENINFO, &var))
 			PERROR("fbset(ioctl)");
 	showmode(&var);
 	/* Don't close the file, as exiting will take care of that */
 	/* close(fh); */

 	return EXIT_SUCCESS;
 }
	/* vi: set sw=4 ts=4: */
	/*
	* Mini fbset implementation for busybox
	*
	* Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
	*
	* 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 2 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, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	* This is a from-scratch implementation of fbset; but the de facto fbset
	* implementation was a good reference. fbset (original) is released under
	* the GPL, and is (c) 1995-1999 by:
	* Geert Uytterhoeven (Geert.Uytterhoeven@cs.kuleuven.ac.be)
	*/

	#include "busybox.h"
	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <fcntl.h>
	#include <errno.h>
	#include <ctype.h>
	#include <sys/ioctl.h>

	#define PERROR(ctx) do { perror(ctx); exit(1); } while(0)

	#define DEFAULTFBDEV "/dev/fb0"
	#define DEFAULTFBMODE "/etc/fb.modes"

	#define OPT_CHANGE 1
	#define OPT_INFO (1 << 1)
	#define OPT_READMODE (1 << 2)

	#define CMD_HELP 0
	#define CMD_FB 1
	#define CMD_DB 2
	#define CMD_GEOMETRY 3
	#define CMD_TIMING 4
	#define CMD_ACCEL 5
	#define CMD_HSYNC 6
	#define CMD_VSYNC 7
	#define CMD_LACED 8
	#define CMD_DOUBLE 9
	/* #define CMD_XCOMPAT 10 */
	#define CMD_ALL 11
	#define CMD_INFO 12
	#define CMD_CHANGE 13

	#ifdef BB_FEATURE_FBSET_FANCY
	#define CMD_XRES 100
	#define CMD_YRES 101
	#define CMD_VXRES 102
	#define CMD_VYRES 103
	#define CMD_DEPTH 104
	#define CMD_MATCH 105
	#define CMD_PIXCLOCK 106
	#define CMD_LEFT 107
	#define CMD_RIGHT 108
	#define CMD_UPPER 109
	#define CMD_LOWER 110
	#define CMD_HSLEN 111
	#define CMD_VSLEN 112
	#define CMD_CSYNC 113
	#define CMD_GSYNC 114
	#define CMD_EXTSYNC 115
	#define CMD_BCAST 116
	#define CMD_RGBA 117
	#define CMD_STEP 118
	#define CMD_MOVE 119
	#endif

	static unsigned int g_options = 0;

	/* Stuff stolen from the kernel's fb.h */
	#define FBIOGET_VSCREENINFO 0x4600
	#define FBIOPUT_VSCREENINFO 0x4601
	#define __u32 unsigned int
	struct fb_bitfield {
	__u32 offset; /* beginning of bitfield */
	__u32 length; /* length of bitfield */
	__u32 msb_right; /* != 0 : Most significant bit is */
	/* right */
	};
	struct fb_var_screeninfo {
	__u32 xres; /* visible resolution */
	__u32 yres;
	__u32 xres_virtual; /* virtual resolution */
	__u32 yres_virtual;
	__u32 xoffset; /* offset from virtual to visible */
	__u32 yoffset; /* resolution */

	__u32 bits_per_pixel; /* guess what */
	__u32 grayscale; /* != 0 Graylevels instead of colors */

	struct fb_bitfield red; /* bitfield in fb mem if true color, */
	struct fb_bitfield green; /* else only length is significant */
	struct fb_bitfield blue;
	struct fb_bitfield transp; /* transparency */

	__u32 nonstd; /* != 0 Non standard pixel format */

	__u32 activate; /* see FB_ACTIVATE_* */

	__u32 height; /* height of picture in mm */
	__u32 width; /* width of picture in mm */

	__u32 accel_flags; /* acceleration flags (hints) */

	/* Timing: All values in pixclocks, except pixclock (of course) */
	__u32 pixclock; /* pixel clock in ps (pico seconds) */
	__u32 left_margin; /* time from sync to picture */
	__u32 right_margin; /* time from picture to sync */
	__u32 upper_margin; /* time from sync to picture */
	__u32 lower_margin;
	__u32 hsync_len; /* length of horizontal sync */
	__u32 vsync_len; /* length of vertical sync */
	__u32 sync; /* see FB_SYNC_* */
	__u32 vmode; /* see FB_VMODE_* */
	__u32 reserved[6]; /* Reserved for future compatibility */
	};


	struct cmdoptions_t {
	char *name;
	unsigned char param_count;
	unsigned char code;
	} g_cmdoptions[] = {
	{
	"-h", 0, CMD_HELP}, {
	"-fb", 1, CMD_FB}, {
	"-db", 1, CMD_DB}, {
	"-a", 0, CMD_ALL}, {
	"-i", 0, CMD_INFO}, {
	"-g", 5, CMD_GEOMETRY}, {
	"-t", 7, CMD_TIMING}, {
	"-accel", 1, CMD_ACCEL}, {
	"-hsync", 1, CMD_HSYNC}, {
	"-vsync", 1, CMD_VSYNC}, {
	"-laced", 1, CMD_LACED}, {
	"-double", 1, CMD_DOUBLE}, {
	"-help", 0, CMD_HELP}, {
	"-n", 0, CMD_CHANGE}, {
	#ifdef BB_FEATURE_FBSET_FANCY
	"-help", 0, CMD_HELP}, {
	"-all", 0, CMD_ALL}, {
	"-xres", 1, CMD_XRES}, {
	"-yres", 1, CMD_YRES}, {
	"-vxres", 1, CMD_VXRES}, {
	"-vyres", 1, CMD_VYRES}, {
	"-depth", 1, CMD_DEPTH}, {
	"-match", 0, CMD_MATCH}, {
	"-geometry", 5, CMD_GEOMETRY}, {
	"-pixclock", 1, CMD_PIXCLOCK}, {
	"-left", 1, CMD_LEFT}, {
	"-right", 1, CMD_RIGHT}, {
	"-upper", 1, CMD_UPPER}, {
	"-lower", 1, CMD_LOWER}, {
	"-hslen", 1, CMD_HSLEN}, {
	"-vslen", 1, CMD_VSLEN}, {
	"-timings", 7, CMD_TIMING}, {
	"-csync", 1, CMD_CSYNC}, {
	"-gsync", 1, CMD_GSYNC}, {
	"-extsync", 1, CMD_EXTSYNC}, {
	"-bcast", 1, CMD_BCAST}, {
	"-rgba", 1, CMD_RGBA}, {
	"-step", 1, CMD_STEP}, {
	"-move", 1, CMD_MOVE}, {
	#endif
	0, 0, 0}
	};

	#ifdef BB_FEATURE_FBSET_READMODE
	/* taken from linux/fb.h */
	#define FB_VMODE_INTERLACED 1 /* interlaced */
	#define FB_VMODE_DOUBLE 2 /* double scan */
	#define FB_SYNC_HOR_HIGH_ACT 1 /* horizontal sync high active */
	#define FB_SYNC_VERT_HIGH_ACT 2 /* vertical sync high active */
	#define FB_SYNC_EXT 4 /* external sync */
	#define FB_SYNC_COMP_HIGH_ACT 8 /* composite sync high active */
	#endif
	static int readmode(struct fb_var_screeninfo base, const char fn,
	const char *mode)
	{
	#ifdef BB_FEATURE_FBSET_READMODE
	FILE *f;
	char buf[256];
	char *p = buf;

	if ((f = fopen(fn, "r")) == NULL)
	PERROR("readmode(fopen)");
	while (!feof(f)) {
	fgets(buf, sizeof(buf), f);
	if ((p = strstr(buf, "mode ")) \|\| (p = strstr(buf, "mode\t"))) {
	p += 5;
	if ((p = strstr(buf, mode))) {
	p += strlen(mode);
	if (!isspace(p) && (p != 0) && (*p != '"')
	&& (p != '\r') && (p != '\n'))
	continue; /* almost, but not quite */
	while (!feof(f)) {
	fgets(buf, sizeof(buf), f);

	if ((p = strstr(buf, "geometry "))) {
	p += 9;

	sscanf(p, "%d %d %d %d %d",
	&(base->xres), &(base->yres),
	&(base->xres_virtual), &(base->yres_virtual),
	&(base->bits_per_pixel));
	} else if ((p = strstr(buf, "timings "))) {
	p += 8;

	sscanf(p, "%d %d %d %d %d %d %d",
	&(base->pixclock),
	&(base->left_margin), &(base->right_margin),
	&(base->upper_margin), &(base->lower_margin),
	&(base->hsync_len), &(base->vsync_len));
	} else if ((p = strstr(buf, "laced "))) {
	p += 6;

	if (strstr(buf, "false")) {
	base->vmode &= ~FB_VMODE_INTERLACED;
	} else {
	base->vmode \|= FB_VMODE_INTERLACED;
	}
	} else if ((p = strstr(buf, "double "))) {
	p += 7;

	if (strstr(buf, "false")) {
	base->vmode &= ~FB_VMODE_DOUBLE;
	} else {
	base->vmode \|= FB_VMODE_DOUBLE;
	}
	} else if ((p = strstr(buf, "vsync "))) {
	p += 6;

	if (strstr(buf, "low")) {
	base->sync &= ~FB_SYNC_VERT_HIGH_ACT;
	} else {
	base->sync \|= FB_SYNC_VERT_HIGH_ACT;
	}
	} else if ((p = strstr(buf, "hsync "))) {
	p += 6;

	if (strstr(buf, "low")) {
	base->sync &= ~FB_SYNC_HOR_HIGH_ACT;
	} else {
	base->sync \|= FB_SYNC_HOR_HIGH_ACT;
	}
	} else if ((p = strstr(buf, "csync "))) {
	p += 6;

	if (strstr(buf, "low")) {
	base->sync &= ~FB_SYNC_COMP_HIGH_ACT;
	} else {
	base->sync \|= FB_SYNC_COMP_HIGH_ACT;
	}
	} else if ((p = strstr(buf, "extsync "))) {
	p += 8;

	if (strstr(buf, "false")) {
	base->sync &= ~FB_SYNC_EXT;
	} else {
	base->sync \|= FB_SYNC_EXT;
	}
	}

	if (strstr(buf, "endmode"))
	return 1;
	}
	}
	}
	}
	#else
	error_msg( "mode reading not compiled in\n");
	#endif
	return 0;
	}

	static void setmode(struct fb_var_screeninfo *base,
	struct fb_var_screeninfo *set)
	{
	if ((int) set->xres > 0)
	base->xres = set->xres;
	if ((int) set->yres > 0)
	base->yres = set->yres;
	if ((int) set->xres_virtual > 0)
	base->xres_virtual = set->xres_virtual;
	if ((int) set->yres_virtual > 0)
	base->yres_virtual = set->yres_virtual;
	if ((int) set->bits_per_pixel > 0)
	base->bits_per_pixel = set->bits_per_pixel;
	}

	static void showmode(struct fb_var_screeninfo *v)
	{
	double drate = 0, hrate = 0, vrate = 0;

	if (v->pixclock) {
	drate = 1e12 / v->pixclock;
	hrate =
	drate / (v->left_margin + v->xres + v->right_margin +
	v->hsync_len);
	vrate =
	hrate / (v->upper_margin + v->yres + v->lower_margin +
	v->vsync_len);
	}
	printf("\nmode \"%ux%u-%u\"\n", v->xres, v->yres, (int) (vrate + 0.5));
	#ifdef BB_FEATURE_FBSET_FANCY
	printf("\t# D: %.3f MHz, H: %.3f kHz, V: %.3f Hz\n", drate / 1e6,
	hrate / 1e3, vrate);
	#endif
	printf("\tgeometry %u %u %u %u %u\n", v->xres, v->yres,
	v->xres_virtual, v->yres_virtual, v->bits_per_pixel);
	printf("\ttimings %u %u %u %u %u %u %u\n", v->pixclock, v->left_margin,
	v->right_margin, v->upper_margin, v->lower_margin, v->hsync_len,
	v->vsync_len);
	printf("\taccel %s\n", (v->accel_flags > 0 ? "true" : "false"));
	printf("\trgba %u/%u,%u/%u,%u/%u,%u/%u\n", v->red.length,
	v->red.offset, v->green.length, v->green.offset, v->blue.length,
	v->blue.offset, v->transp.length, v->transp.offset);
	printf("endmode\n\n");
	}

	static void fbset_usage(void)
	{
	#ifndef BB_FEATURE_TRIVIAL_HELP
	int i;
	#endif

	#ifndef STANDALONE
	fprintf(stderr, "BusyBox v%s (%s) multi-call binary -- GPL2\n\n",
	BB_VER, BB_BT);
	#endif
	fprintf(stderr, "Usage: fbset [options] [mode]\n");
	#ifndef BB_FEATURE_TRIVIAL_HELP
	fprintf(stderr, "\nShows and modifies frame buffer device settings\n\n");
	fprintf(stderr, "The following options are recognized:\n");
	for (i = 0; g_cmdoptions[i].name; i++)
	fprintf(stderr, "\t%s\n", g_cmdoptions[i].name);
	#endif
	exit(-1);
	}

	#ifdef STANDALONE
	int main(int argc, char **argv)
	#else
	extern int fbset_main(int argc, char **argv)
	#endif
	{
	struct fb_var_screeninfo var, varset;
	int fh, i;
	char *fbdev = DEFAULTFBDEV;
	char *modefile = DEFAULTFBMODE;
	char thisarg, mode = NULL;

	memset(&varset, 0xFF, sizeof(varset));

	/* parse cmd args.... why do they have to make things so difficult? */
	argv++;
	argc--;
	for (; argc > 0 && (thisarg = *argv); argc--, argv++) {
	for (i = 0; g_cmdoptions[i].name; i++) {
	if (!strcmp(thisarg, g_cmdoptions[i].name)) {
	if (argc - 1 < g_cmdoptions[i].param_count)
	fbset_usage();
	switch (g_cmdoptions[i].code) {
	case CMD_HELP:
	fbset_usage();
	case CMD_FB:
	fbdev = argv[1];
	break;
	case CMD_DB:
	modefile = argv[1];
	break;
	case CMD_GEOMETRY:
	varset.xres = strtoul(argv[1], 0, 0);
	varset.yres = strtoul(argv[2], 0, 0);
	varset.xres_virtual = strtoul(argv[3], 0, 0);
	varset.yres_virtual = strtoul(argv[4], 0, 0);
	varset.bits_per_pixel = strtoul(argv[5], 0, 0);
	break;
	case CMD_TIMING:
	varset.pixclock = strtoul(argv[1], 0, 0);
	varset.left_margin = strtoul(argv[2], 0, 0);
	varset.right_margin = strtoul(argv[3], 0, 0);
	varset.upper_margin = strtoul(argv[4], 0, 0);
	varset.lower_margin = strtoul(argv[5], 0, 0);
	varset.hsync_len = strtoul(argv[6], 0, 0);
	varset.vsync_len = strtoul(argv[7], 0, 0);
	break;
	case CMD_CHANGE:
	g_options \|= OPT_CHANGE;
	break;
	#ifdef BB_FEATURE_FBSET_FANCY
	case CMD_XRES:
	varset.xres = strtoul(argv[1], 0, 0);
	break;
	case CMD_YRES:
	varset.yres = strtoul(argv[1], 0, 0);
	break;
	#endif
	}
	argc -= g_cmdoptions[i].param_count;
	argv += g_cmdoptions[i].param_count;
	break;
	}
	}
	if (!g_cmdoptions[i].name) {
	if (argc == 1) {
	mode = *argv;
	g_options \|= OPT_READMODE;
	} else {
	fbset_usage();
	}
	}
	}

	if ((fh = open(fbdev, O_RDONLY)) < 0)
	PERROR("fbset(open)");
	if (ioctl(fh, FBIOGET_VSCREENINFO, &var))
	PERROR("fbset(ioctl)");
	if (g_options & OPT_READMODE) {
	if (!readmode(&var, modefile, mode)) {
	error_msg("Unknown video mode `%s'\n", mode);
	return EXIT_FAILURE;
	}
	}

	setmode(&var, &varset);
	if (g_options & OPT_CHANGE)
	if (ioctl(fh, FBIOPUT_VSCREENINFO, &var))
	PERROR("fbset(ioctl)");
	showmode(&var);
	/* Don't close the file, as exiting will take care of that */
	/* close(fh); */

	return EXIT_SUCCESS;
	}