[deliverable/linux.git] / arch / x86 / boot / video-bios.c

/* -*- linux-c -*- ------------------------------------------------------- *
 *
 *   Copyright (C) 1991, 1992 Linus Torvalds
 *   Copyright 2007 rPath, Inc. - All Rights Reserved
 *   Copyright 2009 Intel Corporation; author H. Peter Anvin
 *
 *   This file is part of the Linux kernel, and is made available under
 *   the terms of the GNU General Public License version 2.
 *
 * ----------------------------------------------------------------------- */

/*
 * Standard video BIOS modes
 *
 * We have two options for this; silent and scanned.
 */

#include "boot.h"
#include "video.h"

static __videocard video_bios;

/* Set a conventional BIOS mode */
static int set_bios_mode(u8 mode);

static int bios_set_mode(struct mode_info *mi)
{
	return set_bios_mode(mi->mode - VIDEO_FIRST_BIOS);
}

static int set_bios_mode(u8 mode)
{
	struct biosregs ireg, oreg;
	u8 new_mode;

	initregs(&ireg);
	ireg.al = mode;		/* AH=0x00 Set Video Mode */
	intcall(0x10, &ireg, NULL);


	ireg.ah = 0x0f;		/* Get Current Video Mode */
	intcall(0x10, &ireg, &oreg);

	do_restore = 1;		/* Assume video contents were lost */

	/* Not all BIOSes are clean with the top bit */
	new_mode = ireg.al & 0x7f;

	if (new_mode == mode)
		return 0;	/* Mode change OK */

#ifndef _WAKEUP
	if (new_mode != boot_params.screen_info.orig_video_mode) {
		/* Mode setting failed, but we didn't end up where we
		   started.  That's bad.  Try to revert to the original
		   video mode. */
		ireg.ax = boot_params.screen_info.orig_video_mode;
		intcall(0x10, &ireg, NULL);
	}
#endif
	return -1;
}

static int bios_probe(void)
{
	u8 mode;
#ifdef _WAKEUP
	u8 saved_mode = 0x03;
#else
	u8 saved_mode = boot_params.screen_info.orig_video_mode;
#endif
	u16 crtc;
	struct mode_info *mi;
	int nmodes = 0;

	if (adapter != ADAPTER_EGA && adapter != ADAPTER_VGA)
		return 0;

	set_fs(0);
	crtc = vga_crtc();

	video_bios.modes = GET_HEAP(struct mode_info, 0);

	for (mode = 0x14; mode <= 0x7f; mode++) {
		if (!heap_free(sizeof(struct mode_info)))
			break;

		if (mode_defined(VIDEO_FIRST_BIOS+mode))
			continue;

		if (set_bios_mode(mode))
			continue;

		/* Try to verify that it's a text mode. */

		/* Attribute Controller: make graphics controller disabled */
		if (in_idx(0x3c0, 0x10) & 0x01)
			continue;

		/* Graphics Controller: verify Alpha addressing enabled */
		if (in_idx(0x3ce, 0x06) & 0x01)
			continue;

		/* CRTC cursor location low should be zero(?) */
		if (in_idx(crtc, 0x0f))
			continue;

		mi = GET_HEAP(struct mode_info, 1);
		mi->mode = VIDEO_FIRST_BIOS+mode;
		mi->depth = 0;	/* text */
		mi->x = rdfs16(0x44a);
		mi->y = rdfs8(0x484)+1;
		nmodes++;
	}

	set_bios_mode(saved_mode);

	return nmodes;
}

static __videocard video_bios =
{
	.card_name	= "BIOS",
	.probe		= bios_probe,
	.set_mode	= bios_set_mode,
	.unsafe		= 1,
	.xmode_first	= VIDEO_FIRST_BIOS,
	.xmode_n	= 0x80,
};
Commit	Line	Data
5e8ddcbe PA	1	/* -- linux-c -- ------------------------------------------------------- *
	2	*
	3	* Copyright (C) 1991, 1992 Linus Torvalds
	4	* Copyright 2007 rPath, Inc. - All Rights Reserved
cf06de7b	5	* Copyright 2009 Intel Corporation; author H. Peter Anvin
5e8ddcbe PA	6	*
	7	* This file is part of the Linux kernel, and is made available under
	8	* the terms of the GNU General Public License version 2.
	9	*
	10	* ----------------------------------------------------------------------- */
	11
	12	/*
5e8ddcbe PA	13	* Standard video BIOS modes
	14	*
	15	* We have two options for this; silent and scanned.
	16	*/
	17
	18	#include "boot.h"
	19	#include "video.h"
	20
8bcad30f	21	static __videocard video_bios;
5e8ddcbe PA	22
	23	/* Set a conventional BIOS mode */
	24	static int set_bios_mode(u8 mode);
	25
	26	static int bios_set_mode(struct mode_info *mi)
	27	{
	28	return set_bios_mode(mi->mode - VIDEO_FIRST_BIOS);
	29	}
	30
	31	static int set_bios_mode(u8 mode)
	32	{
cf06de7b	33	struct biosregs ireg, oreg;
5e8ddcbe PA	34	u8 new_mode;
5e8ddcbe PA	35
cf06de7b PA	36	initregs(&ireg);
	37	ireg.al = mode; /* AH=0x00 Set Video Mode */
	38	intcall(0x10, &ireg, NULL);
5e8ddcbe	39
cf06de7b PA	40
	41	ireg.ah = 0x0f; /* Get Current Video Mode */
	42	intcall(0x10, &ireg, &oreg);
5e8ddcbe	43
8218d029	44	do_restore = 1; /* Assume video contents were lost */
cf06de7b PA	45
	46	/* Not all BIOSes are clean with the top bit */
	47	new_mode = ireg.al & 0x7f;
5e8ddcbe PA	48
	49	if (new_mode == mode)
	50	return 0; /* Mode change OK */
	51
e44b7b75	52	#ifndef _WAKEUP
5e8ddcbe PA	53	if (new_mode != boot_params.screen_info.orig_video_mode) {
	54	/* Mode setting failed, but we didn't end up where we
	55	started. That's bad. Try to revert to the original
	56	video mode. */
cf06de7b PA	57	ireg.ax = boot_params.screen_info.orig_video_mode;
cf06de7b PA	58	intcall(0x10, &ireg, NULL);
5e8ddcbe	59	}
e44b7b75	60	#endif
5e8ddcbe PA	61	return -1;
	62	}
	63
	64	static int bios_probe(void)
	65	{
	66	u8 mode;
e44b7b75 PM	67	#ifdef _WAKEUP
	68	u8 saved_mode = 0x03;
	69	#else
5e8ddcbe	70	u8 saved_mode = boot_params.screen_info.orig_video_mode;
e44b7b75	71	#endif
5e8ddcbe PA	72	u16 crtc;
	73	struct mode_info *mi;
	74	int nmodes = 0;
	75
	76	if (adapter != ADAPTER_EGA && adapter != ADAPTER_VGA)
	77	return 0;
	78
	79	set_fs(0);
	80	crtc = vga_crtc();
	81
	82	video_bios.modes = GET_HEAP(struct mode_info, 0);
	83
	84	for (mode = 0x14; mode <= 0x7f; mode++) {
e6e1ace9	85	if (!heap_free(sizeof(struct mode_info)))
5e8ddcbe PA	86	break;
	87
	88	if (mode_defined(VIDEO_FIRST_BIOS+mode))
	89	continue;
	90
	91	if (set_bios_mode(mode))
	92	continue;
	93
	94	/* Try to verify that it's a text mode. */
	95
	96	/* Attribute Controller: make graphics controller disabled */
	97	if (in_idx(0x3c0, 0x10) & 0x01)
	98	continue;
	99
	100	/* Graphics Controller: verify Alpha addressing enabled */
	101	if (in_idx(0x3ce, 0x06) & 0x01)
	102	continue;
	103
	104	/* CRTC cursor location low should be zero(?) */
	105	if (in_idx(crtc, 0x0f))
	106	continue;
	107
	108	mi = GET_HEAP(struct mode_info, 1);
	109	mi->mode = VIDEO_FIRST_BIOS+mode;
1cac5004	110	mi->depth = 0; /* text */
5e8ddcbe PA	111	mi->x = rdfs16(0x44a);
	112	mi->y = rdfs8(0x484)+1;
	113	nmodes++;
	114	}
	115
	116	set_bios_mode(saved_mode);
	117
	118	return nmodes;
	119	}
	120
8bcad30f	121	static __videocard video_bios =
5e8ddcbe	122	{
1cac5004	123	.card_name = "BIOS",
5e8ddcbe PA	124	.probe = bios_probe,
	125	.set_mode = bios_set_mode,
	126	.unsafe = 1,
	127	.xmode_first = VIDEO_FIRST_BIOS,
	128	.xmode_n = 0x80,
	129	};