xref: /freebsd/sys/dev/vt/hw/vga/vt_vga.c (revision 983afe3373c427a080f06dccec820b20891be186)
1 /*-
2  * Copyright (c) 2005 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Copyright (c) 2009 The FreeBSD Foundation
6  * All rights reserved.
7  *
8  * Portions of this software were developed by Ed Schouten
9  * under sponsorship from the FreeBSD Foundation.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "opt_acpi.h"
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 #include <sys/kernel.h>
40 #include <sys/systm.h>
41 #include <sys/bus.h>
42 #include <sys/module.h>
43 #include <sys/rman.h>
44 
45 #include <dev/vt/vt.h>
46 #include <dev/vt/colors/vt_termcolors.h>
47 #include <dev/vt/hw/vga/vt_vga_reg.h>
48 #include <dev/pci/pcivar.h>
49 
50 #include <machine/bus.h>
51 
52 #if ((defined(__amd64__) || defined(__i386__)) && defined(DEV_ACPI))
53 #include <contrib/dev/acpica/include/acpi.h>
54 #endif
55 
56 struct vga_softc {
57 	bus_space_tag_t		 vga_fb_tag;
58 	bus_space_handle_t	 vga_fb_handle;
59 	bus_space_tag_t		 vga_reg_tag;
60 	bus_space_handle_t	 vga_reg_handle;
61 	int			 vga_wmode;
62 	term_color_t		 vga_curfg, vga_curbg;
63 	boolean_t		 vga_enabled;
64 };
65 
66 /* Convenience macros. */
67 #define	MEM_READ1(sc, ofs) \
68 	bus_space_read_1(sc->vga_fb_tag, sc->vga_fb_handle, ofs)
69 #define	MEM_WRITE1(sc, ofs, val) \
70 	bus_space_write_1(sc->vga_fb_tag, sc->vga_fb_handle, ofs, val)
71 #define	REG_READ1(sc, reg) \
72 	bus_space_read_1(sc->vga_reg_tag, sc->vga_reg_handle, reg)
73 #define	REG_WRITE1(sc, reg, val) \
74 	bus_space_write_1(sc->vga_reg_tag, sc->vga_reg_handle, reg, val)
75 
76 #define	VT_VGA_WIDTH	640
77 #define	VT_VGA_HEIGHT	480
78 #define	VT_VGA_MEMSIZE	(VT_VGA_WIDTH * VT_VGA_HEIGHT / 8)
79 
80 /*
81  * VGA is designed to handle 8 pixels at a time (8 pixels in one byte of
82  * memory).
83  */
84 #define	VT_VGA_PIXELS_BLOCK	8
85 
86 /*
87  * We use an off-screen addresses to:
88  *     o  store the background color;
89  *     o  store pixels pattern.
90  * Those addresses are then loaded in the latches once.
91  */
92 #define	VT_VGA_BGCOLOR_OFFSET	VT_VGA_MEMSIZE
93 
94 static vd_probe_t	vga_probe;
95 static vd_init_t	vga_init;
96 static vd_blank_t	vga_blank;
97 static vd_bitblt_text_t	vga_bitblt_text;
98 static vd_bitblt_bmp_t	vga_bitblt_bitmap;
99 static vd_drawrect_t	vga_drawrect;
100 static vd_setpixel_t	vga_setpixel;
101 static vd_postswitch_t	vga_postswitch;
102 
103 static const struct vt_driver vt_vga_driver = {
104 	.vd_name	= "vga",
105 	.vd_probe	= vga_probe,
106 	.vd_init	= vga_init,
107 	.vd_blank	= vga_blank,
108 	.vd_bitblt_text	= vga_bitblt_text,
109 	.vd_bitblt_bmp	= vga_bitblt_bitmap,
110 	.vd_drawrect	= vga_drawrect,
111 	.vd_setpixel	= vga_setpixel,
112 	.vd_postswitch	= vga_postswitch,
113 	.vd_priority	= VD_PRIORITY_GENERIC,
114 };
115 
116 /*
117  * Driver supports both text mode and graphics mode.  Make sure the
118  * buffer is always big enough to support both.
119  */
120 static struct vga_softc vga_conssoftc;
121 VT_DRIVER_DECLARE(vt_vga, vt_vga_driver);
122 
123 static inline void
124 vga_setwmode(struct vt_device *vd, int wmode)
125 {
126 	struct vga_softc *sc = vd->vd_softc;
127 
128 	if (sc->vga_wmode == wmode)
129 		return;
130 
131 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_MODE);
132 	REG_WRITE1(sc, VGA_GC_DATA, wmode);
133 	sc->vga_wmode = wmode;
134 
135 	switch (wmode) {
136 	case 3:
137 		/* Re-enable all plans. */
138 		REG_WRITE1(sc, VGA_SEQ_ADDRESS, VGA_SEQ_MAP_MASK);
139 		REG_WRITE1(sc, VGA_SEQ_DATA, VGA_SEQ_MM_EM3 | VGA_SEQ_MM_EM2 |
140 		    VGA_SEQ_MM_EM1 | VGA_SEQ_MM_EM0);
141 		break;
142 	}
143 }
144 
145 static inline void
146 vga_setfg(struct vt_device *vd, term_color_t color)
147 {
148 	struct vga_softc *sc = vd->vd_softc;
149 
150 	vga_setwmode(vd, 3);
151 
152 	if (sc->vga_curfg == color)
153 		return;
154 
155 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_SET_RESET);
156 	REG_WRITE1(sc, VGA_GC_DATA, cons_to_vga_colors[color]);
157 	sc->vga_curfg = color;
158 }
159 
160 static inline void
161 vga_setbg(struct vt_device *vd, term_color_t color)
162 {
163 	struct vga_softc *sc = vd->vd_softc;
164 
165 	vga_setwmode(vd, 3);
166 
167 	if (sc->vga_curbg == color)
168 		return;
169 
170 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_SET_RESET);
171 	REG_WRITE1(sc, VGA_GC_DATA, cons_to_vga_colors[color]);
172 
173 	/*
174 	 * Write 8 pixels using the background color to an off-screen
175 	 * byte in the video memory.
176 	 */
177 	MEM_WRITE1(sc, VT_VGA_BGCOLOR_OFFSET, 0xff);
178 
179 	/*
180 	 * Read those 8 pixels back to load the background color in the
181 	 * latches register.
182 	 */
183 	MEM_READ1(sc, VT_VGA_BGCOLOR_OFFSET);
184 
185 	sc->vga_curbg = color;
186 
187 	/*
188          * The Set/Reset register doesn't contain the fg color anymore,
189          * store an invalid color.
190 	 */
191 	sc->vga_curfg = 0xff;
192 }
193 
194 /*
195  * Binary searchable table for Unicode to CP437 conversion.
196  */
197 
198 struct unicp437 {
199 	uint16_t	unicode_base;
200 	uint8_t		cp437_base;
201 	uint8_t		length;
202 };
203 
204 static const struct unicp437 cp437table[] = {
205 	{ 0x0020, 0x20, 0x5e }, { 0x00a0, 0x20, 0x00 },
206 	{ 0x00a1, 0xad, 0x00 }, { 0x00a2, 0x9b, 0x00 },
207 	{ 0x00a3, 0x9c, 0x00 }, { 0x00a5, 0x9d, 0x00 },
208 	{ 0x00a6, 0x7c, 0x00 },
209 	{ 0x00a7, 0x15, 0x00 }, { 0x00aa, 0xa6, 0x00 },
210 	{ 0x00ab, 0xae, 0x00 }, { 0x00ac, 0xaa, 0x00 },
211 	{ 0x00b0, 0xf8, 0x00 }, { 0x00b1, 0xf1, 0x00 },
212 	{ 0x00b2, 0xfd, 0x00 }, { 0x00b5, 0xe6, 0x00 },
213 	{ 0x00b6, 0x14, 0x00 }, { 0x00b7, 0xfa, 0x00 },
214 	{ 0x00ba, 0xa7, 0x00 }, { 0x00bb, 0xaf, 0x00 },
215 	{ 0x00bc, 0xac, 0x00 }, { 0x00bd, 0xab, 0x00 },
216 	{ 0x00bf, 0xa8, 0x00 }, { 0x00c4, 0x8e, 0x01 },
217 	{ 0x00c6, 0x92, 0x00 }, { 0x00c7, 0x80, 0x00 },
218 	{ 0x00c9, 0x90, 0x00 }, { 0x00d1, 0xa5, 0x00 },
219 	{ 0x00d6, 0x99, 0x00 }, { 0x00dc, 0x9a, 0x00 },
220 	{ 0x00df, 0xe1, 0x00 }, { 0x00e0, 0x85, 0x00 },
221 	{ 0x00e1, 0xa0, 0x00 }, { 0x00e2, 0x83, 0x00 },
222 	{ 0x00e4, 0x84, 0x00 }, { 0x00e5, 0x86, 0x00 },
223 	{ 0x00e6, 0x91, 0x00 }, { 0x00e7, 0x87, 0x00 },
224 	{ 0x00e8, 0x8a, 0x00 }, { 0x00e9, 0x82, 0x00 },
225 	{ 0x00ea, 0x88, 0x01 }, { 0x00ec, 0x8d, 0x00 },
226 	{ 0x00ed, 0xa1, 0x00 }, { 0x00ee, 0x8c, 0x00 },
227 	{ 0x00ef, 0x8b, 0x00 }, { 0x00f0, 0xeb, 0x00 },
228 	{ 0x00f1, 0xa4, 0x00 }, { 0x00f2, 0x95, 0x00 },
229 	{ 0x00f3, 0xa2, 0x00 }, { 0x00f4, 0x93, 0x00 },
230 	{ 0x00f6, 0x94, 0x00 }, { 0x00f7, 0xf6, 0x00 },
231 	{ 0x00f8, 0xed, 0x00 }, { 0x00f9, 0x97, 0x00 },
232 	{ 0x00fa, 0xa3, 0x00 }, { 0x00fb, 0x96, 0x00 },
233 	{ 0x00fc, 0x81, 0x00 }, { 0x00ff, 0x98, 0x00 },
234 	{ 0x0192, 0x9f, 0x00 }, { 0x0393, 0xe2, 0x00 },
235 	{ 0x0398, 0xe9, 0x00 }, { 0x03a3, 0xe4, 0x00 },
236 	{ 0x03a6, 0xe8, 0x00 }, { 0x03a9, 0xea, 0x00 },
237 	{ 0x03b1, 0xe0, 0x01 }, { 0x03b4, 0xeb, 0x00 },
238 	{ 0x03b5, 0xee, 0x00 }, { 0x03bc, 0xe6, 0x00 },
239 	{ 0x03c0, 0xe3, 0x00 }, { 0x03c3, 0xe5, 0x00 },
240 	{ 0x03c4, 0xe7, 0x00 }, { 0x03c6, 0xed, 0x00 },
241 	{ 0x03d5, 0xed, 0x00 }, { 0x2010, 0x2d, 0x00 },
242 	{ 0x2013, 0x2d, 0x00 },
243 	{ 0x2014, 0x2d, 0x00 }, { 0x2018, 0x60, 0x00 },
244 	{ 0x2019, 0x27, 0x00 }, { 0x201c, 0x22, 0x00 },
245 	{ 0x201d, 0x22, 0x00 }, { 0x2022, 0x07, 0x00 },
246 	{ 0x203c, 0x13, 0x00 }, { 0x207f, 0xfc, 0x00 },
247 	{ 0x20a7, 0x9e, 0x00 }, { 0x20ac, 0xee, 0x00 },
248 	{ 0x2126, 0xea, 0x00 }, { 0x2190, 0x1b, 0x00 },
249 	{ 0x2191, 0x18, 0x00 }, { 0x2192, 0x1a, 0x00 },
250 	{ 0x2193, 0x19, 0x00 }, { 0x2194, 0x1d, 0x00 },
251 	{ 0x2195, 0x12, 0x00 }, { 0x21a8, 0x17, 0x00 },
252 	{ 0x2202, 0xeb, 0x00 }, { 0x2208, 0xee, 0x00 },
253 	{ 0x2211, 0xe4, 0x00 }, { 0x2212, 0x2d, 0x00 },
254 	{ 0x2219, 0xf9, 0x00 }, { 0x221a, 0xfb, 0x00 },
255 	{ 0x221e, 0xec, 0x00 }, { 0x221f, 0x1c, 0x00 },
256 	{ 0x2229, 0xef, 0x00 }, { 0x2248, 0xf7, 0x00 },
257 	{ 0x2261, 0xf0, 0x00 }, { 0x2264, 0xf3, 0x00 },
258 	{ 0x2265, 0xf2, 0x00 }, { 0x2302, 0x7f, 0x00 },
259 	{ 0x2310, 0xa9, 0x00 }, { 0x2320, 0xf4, 0x00 },
260 	{ 0x2321, 0xf5, 0x00 }, { 0x2500, 0xc4, 0x00 },
261 	{ 0x2502, 0xb3, 0x00 }, { 0x250c, 0xda, 0x00 },
262 	{ 0x2510, 0xbf, 0x00 }, { 0x2514, 0xc0, 0x00 },
263 	{ 0x2518, 0xd9, 0x00 }, { 0x251c, 0xc3, 0x00 },
264 	{ 0x2524, 0xb4, 0x00 }, { 0x252c, 0xc2, 0x00 },
265 	{ 0x2534, 0xc1, 0x00 }, { 0x253c, 0xc5, 0x00 },
266 	{ 0x2550, 0xcd, 0x00 }, { 0x2551, 0xba, 0x00 },
267 	{ 0x2552, 0xd5, 0x00 }, { 0x2553, 0xd6, 0x00 },
268 	{ 0x2554, 0xc9, 0x00 }, { 0x2555, 0xb8, 0x00 },
269 	{ 0x2556, 0xb7, 0x00 }, { 0x2557, 0xbb, 0x00 },
270 	{ 0x2558, 0xd4, 0x00 }, { 0x2559, 0xd3, 0x00 },
271 	{ 0x255a, 0xc8, 0x00 }, { 0x255b, 0xbe, 0x00 },
272 	{ 0x255c, 0xbd, 0x00 }, { 0x255d, 0xbc, 0x00 },
273 	{ 0x255e, 0xc6, 0x01 }, { 0x2560, 0xcc, 0x00 },
274 	{ 0x2561, 0xb5, 0x00 }, { 0x2562, 0xb6, 0x00 },
275 	{ 0x2563, 0xb9, 0x00 }, { 0x2564, 0xd1, 0x01 },
276 	{ 0x2566, 0xcb, 0x00 }, { 0x2567, 0xcf, 0x00 },
277 	{ 0x2568, 0xd0, 0x00 }, { 0x2569, 0xca, 0x00 },
278 	{ 0x256a, 0xd8, 0x00 }, { 0x256b, 0xd7, 0x00 },
279 	{ 0x256c, 0xce, 0x00 }, { 0x2580, 0xdf, 0x00 },
280 	{ 0x2584, 0xdc, 0x00 }, { 0x2588, 0xdb, 0x00 },
281 	{ 0x258c, 0xdd, 0x00 }, { 0x2590, 0xde, 0x00 },
282 	{ 0x2591, 0xb0, 0x02 }, { 0x25a0, 0xfe, 0x00 },
283 	{ 0x25ac, 0x16, 0x00 }, { 0x25b2, 0x1e, 0x00 },
284 	{ 0x25ba, 0x10, 0x00 }, { 0x25bc, 0x1f, 0x00 },
285 	{ 0x25c4, 0x11, 0x00 }, { 0x25cb, 0x09, 0x00 },
286 	{ 0x25d8, 0x08, 0x00 }, { 0x25d9, 0x0a, 0x00 },
287 	{ 0x263a, 0x01, 0x01 }, { 0x263c, 0x0f, 0x00 },
288 	{ 0x2640, 0x0c, 0x00 }, { 0x2642, 0x0b, 0x00 },
289 	{ 0x2660, 0x06, 0x00 }, { 0x2663, 0x05, 0x00 },
290 	{ 0x2665, 0x03, 0x01 }, { 0x266a, 0x0d, 0x00 },
291 	{ 0x266c, 0x0e, 0x00 }, { 0x2713, 0xfb, 0x00 },
292 	{ 0x27e8, 0x3c, 0x00 }, { 0x27e9, 0x3e, 0x00 },
293 };
294 
295 static uint8_t
296 vga_get_cp437(term_char_t c)
297 {
298 	int min, mid, max;
299 
300 	min = 0;
301 	max = nitems(cp437table) - 1;
302 
303 	if (c < cp437table[0].unicode_base ||
304 	    c > cp437table[max].unicode_base + cp437table[max].length)
305 		return '?';
306 
307 	while (max >= min) {
308 		mid = (min + max) / 2;
309 		if (c < cp437table[mid].unicode_base)
310 			max = mid - 1;
311 		else if (c > cp437table[mid].unicode_base +
312 		    cp437table[mid].length)
313 			min = mid + 1;
314 		else
315 			return (c - cp437table[mid].unicode_base +
316 			    cp437table[mid].cp437_base);
317 	}
318 
319 	return '?';
320 }
321 
322 static void
323 vga_blank(struct vt_device *vd, term_color_t color)
324 {
325 	struct vga_softc *sc = vd->vd_softc;
326 	u_int ofs;
327 
328 	vga_setfg(vd, color);
329 	for (ofs = 0; ofs < VT_VGA_MEMSIZE; ofs++)
330 		MEM_WRITE1(sc, ofs, 0xff);
331 }
332 
333 static inline void
334 vga_bitblt_put(struct vt_device *vd, u_long dst, term_color_t color,
335     uint8_t v)
336 {
337 	struct vga_softc *sc = vd->vd_softc;
338 
339 	/* Skip empty writes, in order to avoid palette changes. */
340 	if (v != 0x00) {
341 		vga_setfg(vd, color);
342 		/*
343 		 * When this MEM_READ1() gets disabled, all sorts of
344 		 * artifacts occur.  This is because this read loads the
345 		 * set of 8 pixels that are about to be changed.  There
346 		 * is one scenario where we can avoid the read, namely
347 		 * if all pixels are about to be overwritten anyway.
348 		 */
349 		if (v != 0xff) {
350 			MEM_READ1(sc, dst);
351 
352 			/* The bg color was trashed by the reads. */
353 			sc->vga_curbg = 0xff;
354 		}
355 		MEM_WRITE1(sc, dst, v);
356 	}
357 }
358 
359 static void
360 vga_setpixel(struct vt_device *vd, int x, int y, term_color_t color)
361 {
362 
363 	if (vd->vd_flags & VDF_TEXTMODE)
364 		return;
365 
366 	vga_bitblt_put(vd, (y * VT_VGA_WIDTH / 8) + (x / 8), color,
367 	    0x80 >> (x % 8));
368 }
369 
370 static void
371 vga_drawrect(struct vt_device *vd, int x1, int y1, int x2, int y2, int fill,
372     term_color_t color)
373 {
374 	int x, y;
375 
376 	if (vd->vd_flags & VDF_TEXTMODE)
377 		return;
378 
379 	for (y = y1; y <= y2; y++) {
380 		if (fill || (y == y1) || (y == y2)) {
381 			for (x = x1; x <= x2; x++)
382 				vga_setpixel(vd, x, y, color);
383 		} else {
384 			vga_setpixel(vd, x1, y, color);
385 			vga_setpixel(vd, x2, y, color);
386 		}
387 	}
388 }
389 
390 static void
391 vga_compute_shifted_pattern(const uint8_t *src, unsigned int bytes,
392     unsigned int src_x, unsigned int x_count, unsigned int dst_x,
393     uint8_t *pattern, uint8_t *mask)
394 {
395 	unsigned int n;
396 
397 	n = src_x / 8;
398 
399 	/*
400 	 * This mask has bits set, where a pixel (ether 0 or 1)
401 	 * comes from the source bitmap.
402 	 */
403 	if (mask != NULL) {
404 		*mask = (0xff
405 		    >> (8 - x_count))
406 		    << (8 - x_count - dst_x);
407 	}
408 
409 	if (n == (src_x + x_count - 1) / 8) {
410 		/* All the pixels we want are in the same byte. */
411 		*pattern = src[n];
412 		if (dst_x >= src_x)
413 			*pattern >>= (dst_x - src_x % 8);
414 		else
415 			*pattern <<= (src_x % 8 - dst_x);
416 	} else {
417 		/* The pixels we want are split into two bytes. */
418 		if (dst_x >= src_x % 8) {
419 			*pattern =
420 			    src[n] << (8 - dst_x - src_x % 8) |
421 			    src[n + 1] >> (dst_x - src_x % 8);
422 		} else {
423 			*pattern =
424 			    src[n] << (src_x % 8 - dst_x) |
425 			    src[n + 1] >> (8 - src_x % 8 - dst_x);
426 		}
427 	}
428 }
429 
430 static void
431 vga_copy_bitmap_portion(uint8_t *pattern_2colors, uint8_t *pattern_ncolors,
432     const uint8_t *src, const uint8_t *src_mask, unsigned int src_width,
433     unsigned int src_x, unsigned int dst_x, unsigned int x_count,
434     unsigned int src_y, unsigned int dst_y, unsigned int y_count,
435     term_color_t fg, term_color_t bg, int overwrite)
436 {
437 	unsigned int i, bytes;
438 	uint8_t pattern, relevant_bits, mask;
439 
440 	bytes = (src_width + 7) / 8;
441 
442 	for (i = 0; i < y_count; ++i) {
443 		vga_compute_shifted_pattern(src + (src_y + i) * bytes,
444 		    bytes, src_x, x_count, dst_x, &pattern, &relevant_bits);
445 
446 		if (src_mask == NULL) {
447 			/*
448 			 * No src mask. Consider that all wanted bits
449 			 * from the source are "authoritative".
450 			 */
451 			mask = relevant_bits;
452 		} else {
453 			/*
454 			 * There's an src mask. We shift it the same way
455 			 * we shifted the source pattern.
456 			 */
457 			vga_compute_shifted_pattern(
458 			    src_mask + (src_y + i) * bytes,
459 			    bytes, src_x, x_count, dst_x,
460 			    &mask, NULL);
461 
462 			/* Now, only keep the wanted bits among them. */
463 			mask &= relevant_bits;
464 		}
465 
466 		/*
467 		 * Clear bits from the pattern which must be
468 		 * transparent, according to the source mask.
469 		 */
470 		pattern &= mask;
471 
472 		/* Set the bits in the 2-colors array. */
473 		if (overwrite)
474 			pattern_2colors[dst_y + i] &= ~mask;
475 		pattern_2colors[dst_y + i] |= pattern;
476 
477 		if (pattern_ncolors == NULL)
478 			continue;
479 
480 		/*
481 		 * Set the same bits in the n-colors array. This one
482 		 * supports transparency, when a given bit is cleared in
483 		 * all colors.
484 		 */
485 		if (overwrite) {
486 			/*
487 			 * Ensure that the pixels used by this bitmap are
488 			 * cleared in other colors.
489 			 */
490 			for (int j = 0; j < 16; ++j)
491 				pattern_ncolors[(dst_y + i) * 16 + j] &=
492 				    ~mask;
493 		}
494 		pattern_ncolors[(dst_y + i) * 16 + fg] |= pattern;
495 		pattern_ncolors[(dst_y + i) * 16 + bg] |= (~pattern & mask);
496 	}
497 }
498 
499 static void
500 vga_bitblt_pixels_block_2colors(struct vt_device *vd, const uint8_t *masks,
501     term_color_t fg, term_color_t bg,
502     unsigned int x, unsigned int y, unsigned int height)
503 {
504 	unsigned int i, offset;
505 	struct vga_softc *sc;
506 
507 	/*
508 	 * The great advantage of Write Mode 3 is that we just need
509 	 * to load the foreground in the Set/Reset register, load the
510 	 * background color in the latches register (this is done
511 	 * through a write in offscreen memory followed by a read of
512 	 * that data), then write the pattern to video memory. This
513 	 * pattern indicates if the pixel should use the foreground
514 	 * color (bit set) or the background color (bit cleared).
515 	 */
516 
517 	vga_setbg(vd, bg);
518 	vga_setfg(vd, fg);
519 
520 	sc = vd->vd_softc;
521 	offset = (VT_VGA_WIDTH * y + x) / 8;
522 
523 	for (i = 0; i < height; ++i, offset += VT_VGA_WIDTH / 8) {
524 		MEM_WRITE1(sc, offset, masks[i]);
525 	}
526 }
527 
528 static void
529 vga_bitblt_pixels_block_ncolors(struct vt_device *vd, const uint8_t *masks,
530     unsigned int x, unsigned int y, unsigned int height)
531 {
532 	unsigned int i, j, plan, color, offset;
533 	struct vga_softc *sc;
534 	uint8_t mask, plans[height * 4];
535 
536 	sc = vd->vd_softc;
537 
538 	memset(plans, 0, sizeof(plans));
539 
540 	/*
541          * To write a group of pixels using 3 or more colors, we select
542          * Write Mode 0 and write one byte to each plan separately.
543 	 */
544 
545 	/*
546 	 * We first compute each byte: each plan contains one bit of the
547 	 * color code for each of the 8 pixels.
548 	 *
549 	 * For example, if the 8 pixels are like this:
550 	 *     GBBBBBBY
551 	 * where:
552 	 *     G (gray)   = 0b0111
553 	 *     B (black)  = 0b0000
554 	 *     Y (yellow) = 0b0011
555 	 *
556 	 * The corresponding for bytes are:
557 	 *             GBBBBBBY
558 	 *     Plan 0: 10000001 = 0x81
559 	 *     Plan 1: 10000001 = 0x81
560 	 *     Plan 2: 10000000 = 0x80
561 	 *     Plan 3: 00000000 = 0x00
562 	 *             |  |   |
563 	 *             |  |   +-> 0b0011 (Y)
564 	 *             |  +-----> 0b0000 (B)
565 	 *             +--------> 0b0111 (G)
566 	 */
567 
568 	for (i = 0; i < height; ++i) {
569 		for (color = 0; color < 16; ++color) {
570 			mask = masks[i * 16 + color];
571 			if (mask == 0x00)
572 				continue;
573 
574 			for (j = 0; j < 8; ++j) {
575 				if (!((mask >> (7 - j)) & 0x1))
576 					continue;
577 
578 				/* The pixel "j" uses color "color". */
579 				for (plan = 0; plan < 4; ++plan)
580 					plans[i * 4 + plan] |=
581 					    ((color >> plan) & 0x1) << (7 - j);
582 			}
583 		}
584 	}
585 
586 	/*
587 	 * The bytes are ready: we now switch to Write Mode 0 and write
588 	 * all bytes, one plan at a time.
589 	 */
590 	vga_setwmode(vd, 0);
591 
592 	REG_WRITE1(sc, VGA_SEQ_ADDRESS, VGA_SEQ_MAP_MASK);
593 	for (plan = 0; plan < 4; ++plan) {
594 		/* Select plan. */
595 		REG_WRITE1(sc, VGA_SEQ_DATA, 1 << plan);
596 
597 		/* Write all bytes for this plan, from Y to Y+height. */
598 		for (i = 0; i < height; ++i) {
599 			offset = (VT_VGA_WIDTH * (y + i) + x) / 8;
600 			MEM_WRITE1(sc, offset, plans[i * 4 + plan]);
601 		}
602 	}
603 }
604 
605 static void
606 vga_bitblt_one_text_pixels_block(struct vt_device *vd,
607     const struct vt_window *vw, unsigned int x, unsigned int y)
608 {
609 	const struct vt_buf *vb;
610 	const struct vt_font *vf;
611 	unsigned int i, col, row, src_x, x_count;
612 	unsigned int used_colors_list[16], used_colors;
613 	uint8_t pattern_2colors[vw->vw_font->vf_height];
614 	uint8_t pattern_ncolors[vw->vw_font->vf_height * 16];
615 	term_char_t c;
616 	term_color_t fg, bg;
617 	const uint8_t *src;
618 
619 	vb = &vw->vw_buf;
620 	vf = vw->vw_font;
621 
622 	/*
623 	 * The current pixels block.
624 	 *
625 	 * We fill it with portions of characters, because both "grids"
626 	 * may not match.
627 	 *
628 	 * i is the index in this pixels block.
629 	 */
630 
631 	i = x;
632 	used_colors = 0;
633 	memset(used_colors_list, 0, sizeof(used_colors_list));
634 	memset(pattern_2colors, 0, sizeof(pattern_2colors));
635 	memset(pattern_ncolors, 0, sizeof(pattern_ncolors));
636 
637 	if (i < vw->vw_draw_area.tr_begin.tp_col) {
638 		/*
639 		 * i is in the margin used to center the text area on
640 		 * the screen.
641 		 */
642 
643 		i = vw->vw_draw_area.tr_begin.tp_col;
644 	}
645 
646 	while (i < x + VT_VGA_PIXELS_BLOCK &&
647 	    i < vw->vw_draw_area.tr_end.tp_col) {
648 		/*
649 		 * Find which character is drawn on this pixel in the
650 		 * pixels block.
651 		 *
652 		 * While here, record what colors it uses.
653 		 */
654 
655 		col = (i - vw->vw_draw_area.tr_begin.tp_col) / vf->vf_width;
656 		row = (y - vw->vw_draw_area.tr_begin.tp_row) / vf->vf_height;
657 
658 		c = VTBUF_GET_FIELD(vb, row, col);
659 		src = vtfont_lookup(vf, c);
660 
661 		vt_determine_colors(c, VTBUF_ISCURSOR(vb, row, col), &fg, &bg);
662 		if ((used_colors_list[fg] & 0x1) != 0x1)
663 			used_colors++;
664 		if ((used_colors_list[bg] & 0x2) != 0x2)
665 			used_colors++;
666 		used_colors_list[fg] |= 0x1;
667 		used_colors_list[bg] |= 0x2;
668 
669 		/*
670 		 * Compute the portion of the character we want to draw,
671 		 * because the pixels block may start in the middle of a
672 		 * character.
673 		 *
674 		 * The first pixel to draw in the character is
675 		 *     the current position -
676 		 *     the start position of the character
677 		 *
678 		 * The last pixel to draw is either
679 		 *     - the last pixel of the character, or
680 		 *     - the pixel of the character matching the end of
681 		 *       the pixels block
682 		 * whichever comes first. This position is then
683 		 * changed to be relative to the start position of the
684 		 * character.
685 		 */
686 
687 		src_x = i -
688 		    (col * vf->vf_width + vw->vw_draw_area.tr_begin.tp_col);
689 		x_count = min(min(
690 		    (col + 1) * vf->vf_width +
691 		    vw->vw_draw_area.tr_begin.tp_col,
692 		    x + VT_VGA_PIXELS_BLOCK),
693 		    vw->vw_draw_area.tr_end.tp_col);
694 		x_count -= col * vf->vf_width +
695 		    vw->vw_draw_area.tr_begin.tp_col;
696 		x_count -= src_x;
697 
698 		/* Copy a portion of the character. */
699 		vga_copy_bitmap_portion(pattern_2colors, pattern_ncolors,
700 		    src, NULL, vf->vf_width,
701 		    src_x, i % VT_VGA_PIXELS_BLOCK, x_count,
702 		    0, 0, vf->vf_height, fg, bg, 0);
703 
704 		/* We move to the next portion. */
705 		i += x_count;
706 	}
707 
708 #ifndef SC_NO_CUTPASTE
709 	/*
710 	 * Copy the mouse pointer bitmap if it's over the current pixels
711 	 * block.
712 	 *
713 	 * We use the saved cursor position (saved in vt_flush()), because
714 	 * the current position could be different than the one used
715 	 * to mark the area dirty.
716 	 */
717 	term_rect_t drawn_area;
718 
719 	drawn_area.tr_begin.tp_col = x;
720 	drawn_area.tr_begin.tp_row = y;
721 	drawn_area.tr_end.tp_col = x + VT_VGA_PIXELS_BLOCK;
722 	drawn_area.tr_end.tp_row = y + vf->vf_height;
723 	if (vd->vd_mshown && vt_is_cursor_in_area(vd, &drawn_area)) {
724 		struct vt_mouse_cursor *cursor;
725 		unsigned int mx, my;
726 		unsigned int dst_x, src_y, dst_y, y_count;
727 
728 		cursor = vd->vd_mcursor;
729 		mx = vd->vd_mx_drawn + vw->vw_draw_area.tr_begin.tp_col;
730 		my = vd->vd_my_drawn + vw->vw_draw_area.tr_begin.tp_row;
731 
732 		/* Compute the portion of the cursor we want to copy. */
733 		src_x = x > mx ? x - mx : 0;
734 		dst_x = mx > x ? mx - x : 0;
735 		x_count = min(min(min(
736 		    cursor->width - src_x,
737 		    x + VT_VGA_PIXELS_BLOCK - mx),
738 		    vw->vw_draw_area.tr_end.tp_col - mx),
739 		    VT_VGA_PIXELS_BLOCK);
740 
741 		/*
742 		 * The cursor isn't aligned on the Y-axis with
743 		 * characters, so we need to compute the vertical
744 		 * start/count.
745 		 */
746 		src_y = y > my ? y - my : 0;
747 		dst_y = my > y ? my - y : 0;
748 		y_count = min(
749 		    min(cursor->height - src_y, y + vf->vf_height - my),
750 		    vf->vf_height);
751 
752 		/* Copy the cursor portion. */
753 		vga_copy_bitmap_portion(pattern_2colors, pattern_ncolors,
754 		    cursor->map, cursor->mask, cursor->width,
755 		    src_x, dst_x, x_count, src_y, dst_y, y_count,
756 		    vd->vd_mcursor_fg, vd->vd_mcursor_bg, 1);
757 
758 		if ((used_colors_list[vd->vd_mcursor_fg] & 0x1) != 0x1)
759 			used_colors++;
760 		if ((used_colors_list[vd->vd_mcursor_bg] & 0x2) != 0x2)
761 			used_colors++;
762 	}
763 #endif
764 
765 	/*
766 	 * The pixels block is completed, we can now draw it on the
767 	 * screen.
768 	 */
769 	if (used_colors == 2)
770 		vga_bitblt_pixels_block_2colors(vd, pattern_2colors, fg, bg,
771 		    x, y, vf->vf_height);
772 	else
773 		vga_bitblt_pixels_block_ncolors(vd, pattern_ncolors,
774 		    x, y, vf->vf_height);
775 }
776 
777 static void
778 vga_bitblt_text_gfxmode(struct vt_device *vd, const struct vt_window *vw,
779     const term_rect_t *area)
780 {
781 	const struct vt_font *vf;
782 	unsigned int col, row;
783 	unsigned int x1, y1, x2, y2, x, y;
784 
785 	vf = vw->vw_font;
786 
787 	/*
788 	 * Compute the top-left pixel position aligned with the video
789 	 * adapter pixels block size.
790 	 *
791 	 * This is calculated from the top-left column of te dirty area:
792 	 *
793 	 *     1. Compute the top-left pixel of the character:
794 	 *        col * font width + x offset
795 	 *
796 	 *        NOTE: x offset is used to center the text area on the
797 	 *        screen. It's expressed in pixels, not in characters
798 	 *        col/row!
799 	 *
800 	 *     2. Find the pixel further on the left marking the start of
801 	 *        an aligned pixels block (eg. chunk of 8 pixels):
802 	 *        character's x / blocksize * blocksize
803 	 *
804 	 *        The division, being made on integers, achieves the
805 	 *        alignment.
806 	 *
807 	 * For the Y-axis, we need to compute the character's y
808 	 * coordinate, but we don't need to align it.
809 	 */
810 
811 	col = area->tr_begin.tp_col;
812 	row = area->tr_begin.tp_row;
813 	x1 = (int)((col * vf->vf_width + vw->vw_draw_area.tr_begin.tp_col)
814 	     / VT_VGA_PIXELS_BLOCK)
815 	    * VT_VGA_PIXELS_BLOCK;
816 	y1 = row * vf->vf_height + vw->vw_draw_area.tr_begin.tp_row;
817 
818 	/*
819 	 * Compute the bottom right pixel position, again, aligned with
820 	 * the pixels block size.
821 	 *
822 	 * The same rules apply, we just add 1 to base the computation
823 	 * on the "right border" of the dirty area.
824 	 */
825 
826 	col = area->tr_end.tp_col;
827 	row = area->tr_end.tp_row;
828 	x2 = (int)howmany(col * vf->vf_width + vw->vw_draw_area.tr_begin.tp_col,
829 	    VT_VGA_PIXELS_BLOCK)
830 	    * VT_VGA_PIXELS_BLOCK;
831 	y2 = row * vf->vf_height + vw->vw_draw_area.tr_begin.tp_row;
832 
833 	/* Clip the area to the screen size. */
834 	x2 = min(x2, vw->vw_draw_area.tr_end.tp_col);
835 	y2 = min(y2, vw->vw_draw_area.tr_end.tp_row);
836 
837 	/*
838 	 * Now, we take care of N pixels line at a time (the first for
839 	 * loop, N = font height), and for these lines, draw one pixels
840 	 * block at a time (the second for loop), not a character at a
841 	 * time.
842 	 *
843 	 * Therefore, on the X-axis, characters my be drawn partially if
844 	 * they are not aligned on 8-pixels boundary.
845 	 *
846 	 * However, the operation is repeated for the full height of the
847 	 * font before moving to the next character, because it allows
848 	 * to keep the color settings and write mode, before perhaps
849 	 * changing them with the next one.
850 	 */
851 
852 	for (y = y1; y < y2; y += vf->vf_height) {
853 		for (x = x1; x < x2; x += VT_VGA_PIXELS_BLOCK) {
854 			vga_bitblt_one_text_pixels_block(vd, vw, x, y);
855 		}
856 	}
857 }
858 
859 static void
860 vga_bitblt_text_txtmode(struct vt_device *vd, const struct vt_window *vw,
861     const term_rect_t *area)
862 {
863 	struct vga_softc *sc;
864 	const struct vt_buf *vb;
865 	unsigned int col, row;
866 	term_char_t c;
867 	term_color_t fg, bg;
868 	uint8_t ch, attr;
869 
870 	sc = vd->vd_softc;
871 	vb = &vw->vw_buf;
872 
873 	for (row = area->tr_begin.tp_row; row < area->tr_end.tp_row; ++row) {
874 		for (col = area->tr_begin.tp_col;
875 		    col < area->tr_end.tp_col;
876 		    ++col) {
877 			/*
878 			 * Get next character and its associated fg/bg
879 			 * colors.
880 			 */
881 			c = VTBUF_GET_FIELD(vb, row, col);
882 			vt_determine_colors(c, VTBUF_ISCURSOR(vb, row, col),
883 			    &fg, &bg);
884 
885 			/*
886 			 * Convert character to CP437, which is the
887 			 * character set used by the VGA hardware by
888 			 * default.
889 			 */
890 			ch = vga_get_cp437(TCHAR_CHARACTER(c));
891 
892 			/* Convert colors to VGA attributes. */
893 			attr =
894 			    cons_to_vga_colors[bg] << 4 |
895 			    cons_to_vga_colors[fg];
896 
897 			MEM_WRITE1(sc, (row * 80 + col) * 2 + 0,
898 			    ch);
899 			MEM_WRITE1(sc, (row * 80 + col) * 2 + 1,
900 			    attr);
901 		}
902 	}
903 }
904 
905 static void
906 vga_bitblt_text(struct vt_device *vd, const struct vt_window *vw,
907     const term_rect_t *area)
908 {
909 
910 	if (!(vd->vd_flags & VDF_TEXTMODE)) {
911 		vga_bitblt_text_gfxmode(vd, vw, area);
912 	} else {
913 		vga_bitblt_text_txtmode(vd, vw, area);
914 	}
915 }
916 
917 static void
918 vga_bitblt_bitmap(struct vt_device *vd, const struct vt_window *vw,
919     const uint8_t *pattern, const uint8_t *mask,
920     unsigned int width, unsigned int height,
921     unsigned int x, unsigned int y, term_color_t fg, term_color_t bg)
922 {
923 	unsigned int x1, y1, x2, y2, i, j, src_x, dst_x, x_count;
924 	uint8_t pattern_2colors;
925 
926 	/* Align coordinates with the 8-pxels grid. */
927 	x1 = rounddown(x, VT_VGA_PIXELS_BLOCK);
928 	y1 = y;
929 
930 	x2 = roundup(x + width, VT_VGA_PIXELS_BLOCK);
931 	y2 = y + height;
932 	x2 = min(x2, vd->vd_width - 1);
933 	y2 = min(y2, vd->vd_height - 1);
934 
935 	for (j = y1; j < y2; ++j) {
936 		src_x = 0;
937 		dst_x = x - x1;
938 		x_count = VT_VGA_PIXELS_BLOCK - dst_x;
939 
940 		for (i = x1; i < x2; i += VT_VGA_PIXELS_BLOCK) {
941 			pattern_2colors = 0;
942 
943 			vga_copy_bitmap_portion(
944 			    &pattern_2colors, NULL,
945 			    pattern, mask, width,
946 			    src_x, dst_x, x_count,
947 			    j - y1, 0, 1, fg, bg, 0);
948 
949 			vga_bitblt_pixels_block_2colors(vd,
950 			    &pattern_2colors, fg, bg,
951 			    i, j, 1);
952 
953 			src_x += x_count;
954 			dst_x = (dst_x + x_count) % VT_VGA_PIXELS_BLOCK;
955 			x_count = min(width - src_x, VT_VGA_PIXELS_BLOCK);
956 		}
957 	}
958 }
959 
960 static void
961 vga_initialize_graphics(struct vt_device *vd)
962 {
963 	struct vga_softc *sc = vd->vd_softc;
964 
965 	/* Clock select. */
966 	REG_WRITE1(sc, VGA_GEN_MISC_OUTPUT_W, VGA_GEN_MO_VSP | VGA_GEN_MO_HSP |
967 	    VGA_GEN_MO_PB | VGA_GEN_MO_ER | VGA_GEN_MO_IOA);
968 	/* Set sequencer clocking and memory mode. */
969 	REG_WRITE1(sc, VGA_SEQ_ADDRESS, VGA_SEQ_CLOCKING_MODE);
970 	REG_WRITE1(sc, VGA_SEQ_DATA, VGA_SEQ_CM_89);
971 	REG_WRITE1(sc, VGA_SEQ_ADDRESS, VGA_SEQ_MEMORY_MODE);
972 	REG_WRITE1(sc, VGA_SEQ_DATA, VGA_SEQ_MM_OE | VGA_SEQ_MM_EM);
973 
974 	/* Set the graphics controller in graphics mode. */
975 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_MISCELLANEOUS);
976 	REG_WRITE1(sc, VGA_GC_DATA, 0x04 + VGA_GC_MISC_GA);
977 	/* Program the CRT controller. */
978 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_HORIZ_TOTAL);
979 	REG_WRITE1(sc, VGA_CRTC_DATA, 0x5f);			/* 760 */
980 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_HORIZ_DISP_END);
981 	REG_WRITE1(sc, VGA_CRTC_DATA, 0x4f);			/* 640 - 8 */
982 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_START_HORIZ_BLANK);
983 	REG_WRITE1(sc, VGA_CRTC_DATA, 0x50);			/* 640 */
984 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_END_HORIZ_BLANK);
985 	REG_WRITE1(sc, VGA_CRTC_DATA, VGA_CRTC_EHB_CR + 2);
986 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_START_HORIZ_RETRACE);
987 	REG_WRITE1(sc, VGA_CRTC_DATA, 0x54);			/* 672 */
988 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_END_HORIZ_RETRACE);
989 	REG_WRITE1(sc, VGA_CRTC_DATA, VGA_CRTC_EHR_EHB + 0);
990 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_VERT_TOTAL);
991 	REG_WRITE1(sc, VGA_CRTC_DATA, 0x0b);			/* 523 */
992 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_OVERFLOW);
993 	REG_WRITE1(sc, VGA_CRTC_DATA, VGA_CRTC_OF_VT9 | VGA_CRTC_OF_LC8 |
994 	    VGA_CRTC_OF_VBS8 | VGA_CRTC_OF_VRS8 | VGA_CRTC_OF_VDE8);
995 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_MAX_SCAN_LINE);
996 	REG_WRITE1(sc, VGA_CRTC_DATA, VGA_CRTC_MSL_LC9);
997 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_VERT_RETRACE_START);
998 	REG_WRITE1(sc, VGA_CRTC_DATA, 0xea);			/* 480 + 10 */
999 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_VERT_RETRACE_END);
1000 	REG_WRITE1(sc, VGA_CRTC_DATA, 0x0c);
1001 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_VERT_DISPLAY_END);
1002 	REG_WRITE1(sc, VGA_CRTC_DATA, 0xdf);			/* 480 - 1*/
1003 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_OFFSET);
1004 	REG_WRITE1(sc, VGA_CRTC_DATA, 0x28);
1005 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_START_VERT_BLANK);
1006 	REG_WRITE1(sc, VGA_CRTC_DATA, 0xe7);			/* 480 + 7 */
1007 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_END_VERT_BLANK);
1008 	REG_WRITE1(sc, VGA_CRTC_DATA, 0x04);
1009 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_MODE_CONTROL);
1010 	REG_WRITE1(sc, VGA_CRTC_DATA, VGA_CRTC_MC_WB | VGA_CRTC_MC_AW |
1011 	    VGA_CRTC_MC_SRS | VGA_CRTC_MC_CMS);
1012 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_LINE_COMPARE);
1013 	REG_WRITE1(sc, VGA_CRTC_DATA, 0xff);			/* 480 + 31 */
1014 
1015 	REG_WRITE1(sc, VGA_GEN_FEATURE_CTRL_W, 0);
1016 
1017 	REG_WRITE1(sc, VGA_SEQ_ADDRESS, VGA_SEQ_MAP_MASK);
1018 	REG_WRITE1(sc, VGA_SEQ_DATA, VGA_SEQ_MM_EM3 | VGA_SEQ_MM_EM2 |
1019 	    VGA_SEQ_MM_EM1 | VGA_SEQ_MM_EM0);
1020 	REG_WRITE1(sc, VGA_SEQ_ADDRESS, VGA_SEQ_CHAR_MAP_SELECT);
1021 	REG_WRITE1(sc, VGA_SEQ_DATA, 0);
1022 
1023 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_SET_RESET);
1024 	REG_WRITE1(sc, VGA_GC_DATA, 0);
1025 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_ENABLE_SET_RESET);
1026 	REG_WRITE1(sc, VGA_GC_DATA, 0x0f);
1027 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_COLOR_COMPARE);
1028 	REG_WRITE1(sc, VGA_GC_DATA, 0);
1029 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_DATA_ROTATE);
1030 	REG_WRITE1(sc, VGA_GC_DATA, 0);
1031 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_READ_MAP_SELECT);
1032 	REG_WRITE1(sc, VGA_GC_DATA, 0);
1033 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_MODE);
1034 	REG_WRITE1(sc, VGA_GC_DATA, 0);
1035 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_COLOR_DONT_CARE);
1036 	REG_WRITE1(sc, VGA_GC_DATA, 0x0f);
1037 	REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_BIT_MASK);
1038 	REG_WRITE1(sc, VGA_GC_DATA, 0xff);
1039 }
1040 
1041 static int
1042 vga_initialize(struct vt_device *vd, int textmode)
1043 {
1044 	struct vga_softc *sc = vd->vd_softc;
1045 	uint8_t x;
1046 	int timeout;
1047 
1048 	/* Make sure the VGA adapter is not in monochrome emulation mode. */
1049 	x = REG_READ1(sc, VGA_GEN_MISC_OUTPUT_R);
1050 	REG_WRITE1(sc, VGA_GEN_MISC_OUTPUT_W, x | VGA_GEN_MO_IOA);
1051 
1052 	/* Unprotect CRTC registers 0-7. */
1053 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_VERT_RETRACE_END);
1054 	x = REG_READ1(sc, VGA_CRTC_DATA);
1055 	REG_WRITE1(sc, VGA_CRTC_DATA, x & ~VGA_CRTC_VRE_PR);
1056 
1057 	/*
1058 	 * Wait for the vertical retrace.
1059 	 * NOTE: this code reads the VGA_GEN_INPUT_STAT_1 register, which has
1060 	 * the side-effect of clearing the internal flip-flip of the attribute
1061 	 * controller's write register. This means that because this code is
1062 	 * here, we know for sure that the first write to the attribute
1063 	 * controller will be a write to the address register. Removing this
1064 	 * code therefore also removes that guarantee and appropriate measures
1065 	 * need to be taken.
1066 	 */
1067 	timeout = 10000;
1068 	do {
1069 		DELAY(10);
1070 		x = REG_READ1(sc, VGA_GEN_INPUT_STAT_1);
1071 		x &= VGA_GEN_IS1_VR | VGA_GEN_IS1_DE;
1072 	} while (x != (VGA_GEN_IS1_VR | VGA_GEN_IS1_DE) && --timeout != 0);
1073 	if (timeout == 0) {
1074 		printf("Timeout initializing vt_vga\n");
1075 		return (ENXIO);
1076 	}
1077 
1078 	/* Now, disable the sync. signals. */
1079 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_MODE_CONTROL);
1080 	x = REG_READ1(sc, VGA_CRTC_DATA);
1081 	REG_WRITE1(sc, VGA_CRTC_DATA, x & ~VGA_CRTC_MC_HR);
1082 
1083 	/* Asynchronous sequencer reset. */
1084 	REG_WRITE1(sc, VGA_SEQ_ADDRESS, VGA_SEQ_RESET);
1085 	REG_WRITE1(sc, VGA_SEQ_DATA, VGA_SEQ_RST_SR);
1086 
1087 	if (!textmode)
1088 		vga_initialize_graphics(vd);
1089 
1090 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_PRESET_ROW_SCAN);
1091 	REG_WRITE1(sc, VGA_CRTC_DATA, 0);
1092 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_CURSOR_START);
1093 	REG_WRITE1(sc, VGA_CRTC_DATA, VGA_CRTC_CS_COO);
1094 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_CURSOR_END);
1095 	REG_WRITE1(sc, VGA_CRTC_DATA, 0);
1096 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_START_ADDR_HIGH);
1097 	REG_WRITE1(sc, VGA_CRTC_DATA, 0);
1098 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_START_ADDR_LOW);
1099 	REG_WRITE1(sc, VGA_CRTC_DATA, 0);
1100 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_CURSOR_LOC_HIGH);
1101 	REG_WRITE1(sc, VGA_CRTC_DATA, 0);
1102 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_CURSOR_LOC_LOW);
1103 	REG_WRITE1(sc, VGA_CRTC_DATA, 0x59);
1104 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_UNDERLINE_LOC);
1105 	REG_WRITE1(sc, VGA_CRTC_DATA, VGA_CRTC_UL_UL);
1106 
1107 	if (textmode) {
1108 		/* Set the attribute controller to blink disable. */
1109 		REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_MODE_CONTROL);
1110 		REG_WRITE1(sc, VGA_AC_WRITE, 0);
1111 	} else {
1112 		/* Set the attribute controller in graphics mode. */
1113 		REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_MODE_CONTROL);
1114 		REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_MC_GA);
1115 		REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_HORIZ_PIXEL_PANNING);
1116 		REG_WRITE1(sc, VGA_AC_WRITE, 0);
1117 	}
1118 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(0));
1119 	REG_WRITE1(sc, VGA_AC_WRITE, 0);
1120 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(1));
1121 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_B);
1122 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(2));
1123 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_G);
1124 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(3));
1125 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_G | VGA_AC_PAL_B);
1126 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(4));
1127 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_R);
1128 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(5));
1129 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_R | VGA_AC_PAL_B);
1130 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(6));
1131 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_SG | VGA_AC_PAL_R);
1132 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(7));
1133 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_R | VGA_AC_PAL_G | VGA_AC_PAL_B);
1134 
1135 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(8));
1136 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_SR | VGA_AC_PAL_SG |
1137 	    VGA_AC_PAL_SB);
1138 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(9));
1139 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_SR | VGA_AC_PAL_SG |
1140 	    VGA_AC_PAL_SB | VGA_AC_PAL_B);
1141 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(10));
1142 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_SR | VGA_AC_PAL_SG |
1143 	    VGA_AC_PAL_SB | VGA_AC_PAL_G);
1144 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(11));
1145 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_SR | VGA_AC_PAL_SG |
1146 	    VGA_AC_PAL_SB | VGA_AC_PAL_G | VGA_AC_PAL_B);
1147 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(12));
1148 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_SR | VGA_AC_PAL_SG |
1149 	    VGA_AC_PAL_SB | VGA_AC_PAL_R);
1150 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(13));
1151 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_SR | VGA_AC_PAL_SG |
1152 	    VGA_AC_PAL_SB | VGA_AC_PAL_R | VGA_AC_PAL_B);
1153 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(14));
1154 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_SR | VGA_AC_PAL_SG |
1155 	    VGA_AC_PAL_SB | VGA_AC_PAL_R | VGA_AC_PAL_G);
1156 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PALETTE(15));
1157 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_PAL_SR | VGA_AC_PAL_SG |
1158 	    VGA_AC_PAL_SB | VGA_AC_PAL_R | VGA_AC_PAL_G | VGA_AC_PAL_B);
1159 
1160 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_OVERSCAN_COLOR);
1161 	REG_WRITE1(sc, VGA_AC_WRITE, 0);
1162 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_COLOR_PLANE_ENABLE);
1163 	REG_WRITE1(sc, VGA_AC_WRITE, 0x0f);
1164 	REG_WRITE1(sc, VGA_AC_WRITE, VGA_AC_COLOR_SELECT);
1165 	REG_WRITE1(sc, VGA_AC_WRITE, 0);
1166 
1167 	if (!textmode) {
1168 		u_int ofs;
1169 
1170 		/*
1171 		 * Done.  Clear the frame buffer.  All bit planes are
1172 		 * enabled, so a single-paged loop should clear all
1173 		 * planes.
1174 		 */
1175 		for (ofs = 0; ofs < VT_VGA_MEMSIZE; ofs++) {
1176 			MEM_WRITE1(sc, ofs, 0);
1177 		}
1178 	}
1179 
1180 	/* Re-enable the sequencer. */
1181 	REG_WRITE1(sc, VGA_SEQ_ADDRESS, VGA_SEQ_RESET);
1182 	REG_WRITE1(sc, VGA_SEQ_DATA, VGA_SEQ_RST_SR | VGA_SEQ_RST_NAR);
1183 	/* Re-enable the sync signals. */
1184 	REG_WRITE1(sc, VGA_CRTC_ADDRESS, VGA_CRTC_MODE_CONTROL);
1185 	x = REG_READ1(sc, VGA_CRTC_DATA);
1186 	REG_WRITE1(sc, VGA_CRTC_DATA, x | VGA_CRTC_MC_HR);
1187 
1188 	if (!textmode) {
1189 		/* Switch to write mode 3, because we'll mainly do bitblt. */
1190 		REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_MODE);
1191 		REG_WRITE1(sc, VGA_GC_DATA, 3);
1192 		sc->vga_wmode = 3;
1193 
1194 		/*
1195 		 * In Write Mode 3, Enable Set/Reset is ignored, but we
1196 		 * use Write Mode 0 to write a group of 8 pixels using
1197 		 * 3 or more colors. In this case, we want to disable
1198 		 * Set/Reset: set Enable Set/Reset to 0.
1199 		 */
1200 		REG_WRITE1(sc, VGA_GC_ADDRESS, VGA_GC_ENABLE_SET_RESET);
1201 		REG_WRITE1(sc, VGA_GC_DATA, 0x00);
1202 
1203 		/*
1204 		 * Clear the colors we think are loaded into Set/Reset or
1205 		 * the latches.
1206 		 */
1207 		sc->vga_curfg = sc->vga_curbg = 0xff;
1208 	}
1209 
1210 	return (0);
1211 }
1212 
1213 static bool
1214 vga_acpi_disabled(void)
1215 {
1216 #if ((defined(__amd64__) || defined(__i386__)) && defined(DEV_ACPI))
1217 	ACPI_TABLE_FADT *fadt;
1218 	vm_paddr_t physaddr;
1219 	uint16_t flags;
1220 
1221 	physaddr = acpi_find_table(ACPI_SIG_FADT);
1222 	if (physaddr == 0)
1223 		return (false);
1224 
1225 	fadt = acpi_map_table(physaddr, ACPI_SIG_FADT);
1226 	if (fadt == NULL) {
1227 		printf("vt_vga: unable to map FADT ACPI table\n");
1228 		return (false);
1229 	}
1230 
1231 	flags = fadt->BootFlags;
1232 	acpi_unmap_table(fadt);
1233 
1234 	if (flags & ACPI_FADT_NO_VGA)
1235 		return (true);
1236 #endif
1237 
1238 	return (false);
1239 }
1240 
1241 static int
1242 vga_probe(struct vt_device *vd)
1243 {
1244 
1245 	return (vga_acpi_disabled() ? CN_DEAD : CN_INTERNAL);
1246 }
1247 
1248 static int
1249 vga_init(struct vt_device *vd)
1250 {
1251 	struct vga_softc *sc;
1252 	int textmode;
1253 
1254 	if (vd->vd_softc == NULL)
1255 		vd->vd_softc = (void *)&vga_conssoftc;
1256 	sc = vd->vd_softc;
1257 
1258 	if (vd->vd_flags & VDF_DOWNGRADE && vd->vd_video_dev != NULL)
1259 		vga_pci_repost(vd->vd_video_dev);
1260 
1261 #if defined(__amd64__) || defined(__i386__)
1262 	sc->vga_fb_tag = X86_BUS_SPACE_MEM;
1263 	sc->vga_reg_tag = X86_BUS_SPACE_IO;
1264 #else
1265 # error "Architecture not yet supported!"
1266 #endif
1267 
1268 	bus_space_map(sc->vga_reg_tag, VGA_REG_BASE, VGA_REG_SIZE, 0,
1269 	    &sc->vga_reg_handle);
1270 
1271 	/*
1272 	 * If "hw.vga.textmode" is not set and we're running on hypervisor,
1273 	 * we use text mode by default, this is because when we're on
1274 	 * hypervisor, vt(4) is usually much slower in graphics mode than
1275 	 * in text mode, especially when we're on Hyper-V.
1276 	 */
1277 	textmode = vm_guest != VM_GUEST_NO;
1278 	TUNABLE_INT_FETCH("hw.vga.textmode", &textmode);
1279 	if (textmode) {
1280 		vd->vd_flags |= VDF_TEXTMODE;
1281 		vd->vd_width = 80;
1282 		vd->vd_height = 25;
1283 		bus_space_map(sc->vga_fb_tag, VGA_TXT_BASE, VGA_TXT_SIZE, 0,
1284 		    &sc->vga_fb_handle);
1285 	} else {
1286 		vd->vd_width = VT_VGA_WIDTH;
1287 		vd->vd_height = VT_VGA_HEIGHT;
1288 		bus_space_map(sc->vga_fb_tag, VGA_MEM_BASE, VGA_MEM_SIZE, 0,
1289 		    &sc->vga_fb_handle);
1290 	}
1291 	if (vga_initialize(vd, textmode) != 0)
1292 		return (CN_DEAD);
1293 	sc->vga_enabled = true;
1294 
1295 	return (CN_INTERNAL);
1296 }
1297 
1298 static void
1299 vga_postswitch(struct vt_device *vd)
1300 {
1301 
1302 	/* Reinit VGA mode, to restore view after app which change mode. */
1303 	vga_initialize(vd, (vd->vd_flags & VDF_TEXTMODE));
1304 	/* Ask vt(9) to update chars on visible area. */
1305 	vd->vd_flags |= VDF_INVALID;
1306 }
1307 
1308 /* Dummy NewBus functions to reserve the resources used by the vt_vga driver */
1309 static void
1310 vtvga_identify(driver_t *driver, device_t parent)
1311 {
1312 
1313 	if (!vga_conssoftc.vga_enabled)
1314 		return;
1315 
1316 	if (BUS_ADD_CHILD(parent, 0, driver->name, 0) == NULL)
1317 		panic("Unable to attach vt_vga console");
1318 }
1319 
1320 static int
1321 vtvga_probe(device_t dev)
1322 {
1323 
1324 	device_set_desc(dev, "VT VGA driver");
1325 
1326 	return (BUS_PROBE_NOWILDCARD);
1327 }
1328 
1329 static int
1330 vtvga_attach(device_t dev)
1331 {
1332 	struct resource *pseudo_phys_res;
1333 	int res_id;
1334 
1335 	res_id = 0;
1336 	pseudo_phys_res = bus_alloc_resource(dev, SYS_RES_MEMORY,
1337 	    &res_id, VGA_MEM_BASE, VGA_MEM_BASE + VGA_MEM_SIZE - 1,
1338 	    VGA_MEM_SIZE, RF_ACTIVE);
1339 	if (pseudo_phys_res == NULL)
1340 		panic("Unable to reserve vt_vga memory");
1341 	return (0);
1342 }
1343 
1344 /*-------------------- Private Device Attachment Data  -----------------------*/
1345 static device_method_t vtvga_methods[] = {
1346 	/* Device interface */
1347 	DEVMETHOD(device_identify,	vtvga_identify),
1348 	DEVMETHOD(device_probe,         vtvga_probe),
1349 	DEVMETHOD(device_attach,        vtvga_attach),
1350 
1351 	DEVMETHOD_END
1352 };
1353 
1354 DEFINE_CLASS_0(vtvga, vtvga_driver, vtvga_methods, 0);
1355 devclass_t vtvga_devclass;
1356 
1357 DRIVER_MODULE(vtvga, nexus, vtvga_driver, vtvga_devclass, NULL, NULL);
1358