wsdisplay_vcons.c revision 1.13 1 /* $NetBSD: wsdisplay_vcons.c,v 1.13 2007/07/28 22:35:56 rumble Exp $ */
2
3 /*-
4 * Copyright (c) 2005, 2006 Michael Lorenz
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the NetBSD
18 * Foundation, Inc. and its contributors.
19 * 4. Neither the name of The NetBSD Foundation nor the names of its
20 * contributors may be used to endorse or promote products derived
21 * from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 * POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: wsdisplay_vcons.c,v 1.13 2007/07/28 22:35:56 rumble Exp $");
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/buf.h>
43 #include <sys/device.h>
44 #include <sys/ioctl.h>
45 #include <sys/malloc.h>
46 #include <sys/mman.h>
47 #include <sys/tty.h>
48 #include <sys/conf.h>
49 #include <sys/proc.h>
50 #include <sys/kthread.h>
51 #include <sys/tprintf.h>
52
53 #include <dev/wscons/wsdisplayvar.h>
54 #include <dev/wscons/wsconsio.h>
55 #include <dev/wsfont/wsfont.h>
56 #include <dev/rasops/rasops.h>
57
58 #include <dev/wscons/wsdisplay_vconsvar.h>
59
60 static void vcons_dummy_init_screen(void *, struct vcons_screen *, int,
61 long *);
62
63 static int vcons_ioctl(void *, void *, u_long, void *, int, struct lwp *);
64 static int vcons_alloc_screen(void *, const struct wsscreen_descr *, void **,
65 int *, int *, long *);
66 static void vcons_free_screen(void *, void *);
67 static int vcons_show_screen(void *, void *, int, void (*)(void *, int, int),
68 void *);
69
70 static void vcons_do_switch(struct vcons_data *);
71
72 /* methods that work only on text buffers */
73 static void vcons_copycols_buffer(void *, int, int, int, int);
74 static void vcons_erasecols_buffer(void *, int, int, int, long);
75 static void vcons_copyrows_buffer(void *, int, int, int);
76 static void vcons_eraserows_buffer(void *, int, int, long);
77 static void vcons_putchar_buffer(void *, int, int, u_int, long);
78
79 /*
80 * actual wrapper methods which call both the _buffer ones above and the
81 * driver supplied ones to do the drawing
82 */
83 static void vcons_copycols(void *, int, int, int, int);
84 static void vcons_erasecols(void *, int, int, int, long);
85 static void vcons_copyrows(void *, int, int, int);
86 static void vcons_eraserows(void *, int, int, long);
87 static void vcons_putchar(void *, int, int, u_int, long);
88 static void vcons_cursor(void *, int, int, int);
89
90 /* support for readin/writing text buffers. For wsmoused */
91 static int vcons_putwschar(struct vcons_screen *, struct wsdisplay_char *);
92 static int vcons_getwschar(struct vcons_screen *, struct wsdisplay_char *);
93
94 static void vcons_lock(struct vcons_screen *);
95 static void vcons_unlock(struct vcons_screen *);
96
97
98 int
99 vcons_init(struct vcons_data *vd, void *cookie, struct wsscreen_descr *def,
100 struct wsdisplay_accessops *ao)
101 {
102
103 /* zero out everything so we can rely on untouched fields being 0 */
104 memset(vd, 0, sizeof(struct vcons_data));
105
106 vd->cookie = cookie;
107
108 vd->init_screen = vcons_dummy_init_screen;
109 vd->show_screen_cb = NULL;
110
111 /* keep a copy of the accessops that we replace below with our
112 * own wrappers */
113 vd->ioctl = ao->ioctl;
114
115 /* configure the accessops */
116 ao->ioctl = vcons_ioctl;
117 ao->alloc_screen = vcons_alloc_screen;
118 ao->free_screen = vcons_free_screen;
119 ao->show_screen = vcons_show_screen;
120
121 LIST_INIT(&vd->screens);
122 vd->active = NULL;
123 vd->wanted = NULL;
124 vd->currenttype = def;
125 callout_init(&vd->switch_callout, 0);
126
127 /*
128 * a lock to serialize access to the framebuffer.
129 * when switching screens we need to make sure there's no rasops
130 * operation in progress
131 */
132 #ifdef DIAGNOSTIC
133 vd->switch_poll_count = 0;
134 #endif
135 return 0;
136 }
137
138 static void
139 vcons_lock(struct vcons_screen *scr)
140 {
141 #ifdef VCONS_PARANOIA
142 int s;
143
144 s = splhigh();
145 #endif
146 SCREEN_BUSY(scr);
147 #ifdef VCONS_PARANOIA
148 splx(s);
149 #endif
150 }
151
152 static void
153 vcons_unlock(struct vcons_screen *scr)
154 {
155 #ifdef VCONS_PARANOIA
156 int s;
157
158 s = splhigh();
159 #endif
160 SCREEN_IDLE(scr);
161 #ifdef VCONS_PARANOIA
162 splx(s);
163 #endif
164 }
165
166 static void
167 vcons_dummy_init_screen(void *cookie,
168 struct vcons_screen *scr, int exists,
169 long *defattr)
170 {
171
172 /*
173 * default init_screen() method.
174 * Needs to be overwritten so we bitch and whine in case anyone ends
175 * up in here.
176 */
177 printf("vcons_init_screen: dummy function called. Your driver is "
178 "supposed to supply a replacement for proper operation\n");
179 }
180
181 int
182 vcons_init_screen(struct vcons_data *vd, struct vcons_screen *scr,
183 int existing, long *defattr)
184 {
185 struct rasops_info *ri = &scr->scr_ri;
186 int cnt, i;
187
188 scr->scr_cookie = vd->cookie;
189 scr->scr_vd = scr->scr_origvd = vd;
190 SCREEN_IDLE(scr);
191
192 /*
193 * call the driver-supplied init_screen function which is expected
194 * to set up rasops_info, override cursor() and probably others
195 */
196 vd->init_screen(vd->cookie, scr, existing, defattr);
197
198 /*
199 * save the non virtual console aware rasops and replace them with
200 * our wrappers
201 */
202 vd->eraserows = ri->ri_ops.eraserows;
203 vd->copyrows = ri->ri_ops.copyrows;
204 vd->erasecols = ri->ri_ops.erasecols;
205 vd->copycols = ri->ri_ops.copycols;
206 vd->putchar = ri->ri_ops.putchar;
207 vd->cursor = ri->ri_ops.cursor;
208
209 ri->ri_ops.eraserows = vcons_eraserows;
210 ri->ri_ops.copyrows = vcons_copyrows;
211 ri->ri_ops.erasecols = vcons_erasecols;
212 ri->ri_ops.copycols = vcons_copycols;
213 ri->ri_ops.putchar = vcons_putchar;
214 ri->ri_ops.cursor = vcons_cursor;
215 ri->ri_hw = scr;
216
217 /*
218 * we allocate both chars and attributes in one chunk, attributes first
219 * because they have the (potentially) bigger alignment
220 */
221 cnt = ri->ri_rows * ri->ri_cols;
222 scr->scr_attrs = (long *)malloc(cnt * (sizeof(long) +
223 sizeof(uint16_t)), M_DEVBUF, M_WAITOK);
224 if (scr->scr_attrs == NULL)
225 return ENOMEM;
226
227 scr->scr_chars = (uint16_t *)&scr->scr_attrs[cnt];
228
229 ri->ri_ops.allocattr(ri, WS_DEFAULT_FG, WS_DEFAULT_BG, 0, defattr);
230 scr->scr_defattr = *defattr;
231
232 /*
233 * fill the attribute buffer with *defattr, chars with 0x20
234 * since we don't know if the driver tries to mimic firmware output or
235 * reset everything we do nothing to VRAM here, any driver that feels
236 * the need to clear screen or something will have to do it on its own
237 * Additional screens will start out in the background anyway so
238 * cleaning or not only really affects the initial console screen
239 */
240 for (i = 0; i < cnt; i++) {
241 scr->scr_attrs[i] = *defattr;
242 scr->scr_chars[i] = 0x20;
243 }
244
245 if(vd->active == NULL) {
246 vd->active = scr;
247 SCREEN_VISIBLE(scr);
248 }
249
250 if (existing) {
251 SCREEN_VISIBLE(scr);
252 vd->active = scr;
253 } else {
254 SCREEN_INVISIBLE(scr);
255 }
256
257 LIST_INSERT_HEAD(&vd->screens, scr, next);
258 return 0;
259 }
260
261 static void
262 vcons_do_switch(struct vcons_data *vd)
263 {
264 struct vcons_screen *scr, *oldscr;
265
266 scr = vd->wanted;
267 if (!scr) {
268 printf("vcons_switch_screen: disappeared\n");
269 vd->switch_cb(vd->switch_cb_arg, EIO, 0);
270 return;
271 }
272 oldscr = vd->active; /* can be NULL! */
273
274 /*
275 * if there's an old, visible screen we mark it invisible and wait
276 * until it's not busy so we can safely switch
277 */
278 if (oldscr != NULL) {
279 SCREEN_INVISIBLE(oldscr);
280 if (SCREEN_IS_BUSY(oldscr)) {
281 callout_reset(&vd->switch_callout, 1,
282 (void(*)(void *))vcons_do_switch, vd);
283 #ifdef DIAGNOSTIC
284 /* bitch if we wait too long */
285 vd->switch_poll_count++;
286 if (vd->switch_poll_count > 100) {
287 panic("vcons: screen still busy");
288 }
289 #endif
290 return;
291 }
292 /* invisible screen -> no visible cursor image */
293 oldscr->scr_ri.ri_flg &= ~RI_CURSOR;
294 #ifdef DIAGNOSTIC
295 vd->switch_poll_count = 0;
296 #endif
297 }
298
299 if (scr == oldscr)
300 return;
301
302 #ifdef DIAGNOSTIC
303 if (SCREEN_IS_VISIBLE(scr))
304 panic("vcons_switch_screen: already active");
305 #endif
306
307 #ifdef notyet
308 if (vd->currenttype != type) {
309 vcons_set_screentype(vd, type);
310 vd->currenttype = type;
311 }
312 #endif
313
314 SCREEN_VISIBLE(scr);
315 vd->active = scr;
316 vd->wanted = NULL;
317
318 if (vd->show_screen_cb != NULL)
319 vd->show_screen_cb(scr);
320
321 if ((scr->scr_flags & VCONS_NO_REDRAW) == 0)
322 vcons_redraw_screen(scr);
323
324 if (vd->switch_cb)
325 vd->switch_cb(vd->switch_cb_arg, 0, 0);
326 }
327
328 void
329 vcons_redraw_screen(struct vcons_screen *scr)
330 {
331 uint16_t *charptr = scr->scr_chars;
332 long *attrptr = scr->scr_attrs;
333 struct rasops_info *ri = &scr->scr_ri;
334 int i, j, offset;
335
336 vcons_lock(scr);
337 if (SCREEN_IS_VISIBLE(scr) && SCREEN_CAN_DRAW(scr)) {
338
339 /*
340 * only clear the screen when RI_FULLCLEAR is set since we're
341 * going to overwrite every single character cell anyway
342 */
343 if (ri->ri_flg & RI_FULLCLEAR) {
344 scr->scr_vd->eraserows(ri, 0, ri->ri_rows,
345 scr->scr_defattr);
346 }
347
348 /* redraw the screen */
349 offset = 0;
350 for (i = 0; i < ri->ri_rows; i++) {
351 for (j = 0; j < ri->ri_cols; j++) {
352 /*
353 * no need to use the wrapper function - we
354 * don't change any characters or attributes
355 * and we already made sure the screen we're
356 * working on is visible
357 */
358 scr->scr_vd->putchar(ri, i, j,
359 charptr[offset], attrptr[offset]);
360 offset++;
361 }
362 }
363 ri->ri_flg &= ~RI_CURSOR;
364 scr->scr_vd->cursor(ri, 1, ri->ri_crow, ri->ri_ccol);
365 }
366 vcons_unlock(scr);
367 }
368
369 static int
370 vcons_ioctl(void *v, void *vs, u_long cmd, void *data, int flag,
371 struct lwp *l)
372 {
373 struct vcons_data *vd = v;
374 int error;
375
376 switch (cmd) {
377 case WSDISPLAYIO_GETWSCHAR:
378 error = vcons_getwschar((struct vcons_screen *)vs,
379 (struct wsdisplay_char *)data);
380 break;
381
382 case WSDISPLAYIO_PUTWSCHAR:
383 error = vcons_putwschar((struct vcons_screen *)vs,
384 (struct wsdisplay_char *)data);
385 break;
386
387 default:
388 if (vd->ioctl != NULL)
389 error = (*vd->ioctl)(v, vs, cmd, data, flag, l);
390 else
391 error = EPASSTHROUGH;
392 }
393
394 return error;
395 }
396
397 static int
398 vcons_alloc_screen(void *v, const struct wsscreen_descr *type, void **cookiep,
399 int *curxp, int *curyp, long *defattrp)
400 {
401 struct vcons_data *vd = v;
402 struct vcons_screen *scr;
403 int ret;
404
405 scr = malloc(sizeof(struct vcons_screen), M_DEVBUF, M_WAITOK | M_ZERO);
406 if (scr == NULL)
407 return ENOMEM;
408
409 scr->scr_flags = 0;
410 scr->scr_status = 0;
411 scr->scr_busy = 0;
412 scr->scr_type = type;
413
414 ret = vcons_init_screen(vd, scr, 0, defattrp);
415 if (ret != 0) {
416 free(scr, M_DEVBUF);
417 return ret;
418 }
419
420 if (vd->active == NULL) {
421 SCREEN_VISIBLE(scr);
422 vd->active = scr;
423 vd->currenttype = type;
424 }
425
426 *cookiep = scr;
427 *curxp = scr->scr_ri.ri_ccol;
428 *curyp = scr->scr_ri.ri_crow;
429 return 0;
430 }
431
432 static void
433 vcons_free_screen(void *v, void *cookie)
434 {
435 struct vcons_data *vd = v;
436 struct vcons_screen *scr = cookie;
437
438 vcons_lock(scr);
439 /* there should be no rasops activity here */
440
441 LIST_REMOVE(scr, next);
442
443 if ((scr->scr_flags & VCONS_SCREEN_IS_STATIC) == 0) {
444 free(scr->scr_attrs, M_DEVBUF);
445 free(scr, M_DEVBUF);
446 } else {
447 /*
448 * maybe we should just restore the old rasops_info methods
449 * and free the character/attribute buffer here?
450 */
451 #ifdef VCONS_DEBUG
452 panic("vcons_free_screen: console");
453 #else
454 printf("vcons_free_screen: console\n");
455 #endif
456 }
457
458 if (vd->active == scr)
459 vd->active = NULL;
460 }
461
462 static int
463 vcons_show_screen(void *v, void *cookie, int waitok,
464 void (*cb)(void *, int, int), void *cb_arg)
465 {
466 struct vcons_data *vd = v;
467 struct vcons_screen *scr;
468
469 scr = cookie;
470 if (scr == vd->active)
471 return 0;
472
473 vd->wanted = scr;
474 vd->switch_cb = cb;
475 vd->switch_cb_arg = cb_arg;
476 if (cb) {
477 callout_reset(&vd->switch_callout, 0,
478 (void(*)(void *))vcons_do_switch, vd);
479 return EAGAIN;
480 }
481
482 vcons_do_switch(vd);
483 return 0;
484 }
485
486 /* wrappers for rasops_info methods */
487
488 static void
489 vcons_copycols_buffer(void *cookie, int row, int srccol, int dstcol, int ncols)
490 {
491 struct rasops_info *ri = cookie;
492 struct vcons_screen *scr = ri->ri_hw;
493 int from = srccol + row * ri->ri_cols;
494 int to = dstcol + row * ri->ri_cols;
495
496 memmove(&scr->scr_attrs[to], &scr->scr_attrs[from],
497 ncols * sizeof(long));
498 memmove(&scr->scr_chars[to], &scr->scr_chars[from],
499 ncols * sizeof(uint16_t));
500 }
501
502 static void
503 vcons_copycols(void *cookie, int row, int srccol, int dstcol, int ncols)
504 {
505 struct rasops_info *ri = cookie;
506 struct vcons_screen *scr = ri->ri_hw;
507
508 vcons_copycols_buffer(cookie, row, srccol, dstcol, ncols);
509
510 vcons_lock(scr);
511 if (SCREEN_IS_VISIBLE(scr) && SCREEN_CAN_DRAW(scr)) {
512 scr->scr_vd->copycols(cookie, row, srccol, dstcol, ncols);
513 }
514 vcons_unlock(scr);
515 }
516
517 static void
518 vcons_erasecols_buffer(void *cookie, int row, int startcol, int ncols, long fillattr)
519 {
520 struct rasops_info *ri = cookie;
521 struct vcons_screen *scr = ri->ri_hw;
522 int start = startcol + row * ri->ri_cols;
523 int end = start + ncols, i;
524
525 for (i = start; i < end; i++) {
526 scr->scr_attrs[i] = fillattr;
527 scr->scr_chars[i] = 0x20;
528 }
529 }
530
531 static void
532 vcons_erasecols(void *cookie, int row, int startcol, int ncols, long fillattr)
533 {
534 struct rasops_info *ri = cookie;
535 struct vcons_screen *scr = ri->ri_hw;
536
537 vcons_erasecols_buffer(cookie, row, startcol, ncols, fillattr);
538
539 vcons_lock(scr);
540 if (SCREEN_IS_VISIBLE(scr) && SCREEN_CAN_DRAW(scr)) {
541 scr->scr_vd->erasecols(cookie, row, startcol, ncols,
542 fillattr);
543 }
544 vcons_unlock(scr);
545 }
546
547 static void
548 vcons_copyrows_buffer(void *cookie, int srcrow, int dstrow, int nrows)
549 {
550 struct rasops_info *ri = cookie;
551 struct vcons_screen *scr = ri->ri_hw;
552 int from, to, len;
553
554 from = ri->ri_cols * srcrow;
555 to = ri->ri_cols * dstrow;
556 len = ri->ri_cols * nrows;
557
558 memmove(&scr->scr_attrs[to], &scr->scr_attrs[from],
559 len * sizeof(long));
560 memmove(&scr->scr_chars[to], &scr->scr_chars[from],
561 len * sizeof(uint16_t));
562 }
563
564 static void
565 vcons_copyrows(void *cookie, int srcrow, int dstrow, int nrows)
566 {
567 struct rasops_info *ri = cookie;
568 struct vcons_screen *scr = ri->ri_hw;
569
570 vcons_copyrows_buffer(cookie, srcrow, dstrow, nrows);
571
572 vcons_lock(scr);
573 if (SCREEN_IS_VISIBLE(scr) && SCREEN_CAN_DRAW(scr)) {
574 scr->scr_vd->copyrows(cookie, srcrow, dstrow, nrows);
575 }
576 vcons_unlock(scr);
577 }
578
579 static void
580 vcons_eraserows_buffer(void *cookie, int row, int nrows, long fillattr)
581 {
582 struct rasops_info *ri = cookie;
583 struct vcons_screen *scr = ri->ri_hw;
584 int start, end, i;
585
586 start = ri->ri_cols * row;
587 end = ri->ri_cols * (row + nrows);
588
589 for (i = start; i < end; i++) {
590 scr->scr_attrs[i] = fillattr;
591 scr->scr_chars[i] = 0x20;
592 }
593 }
594
595 static void
596 vcons_eraserows(void *cookie, int row, int nrows, long fillattr)
597 {
598 struct rasops_info *ri = cookie;
599 struct vcons_screen *scr = ri->ri_hw;
600
601 vcons_eraserows_buffer(cookie, row, nrows, fillattr);
602
603 vcons_lock(scr);
604 if (SCREEN_IS_VISIBLE(scr) && SCREEN_CAN_DRAW(scr)) {
605 scr->scr_vd->eraserows(cookie, row, nrows, fillattr);
606 }
607 vcons_unlock(scr);
608 }
609
610 static void
611 vcons_putchar_buffer(void *cookie, int row, int col, u_int c, long attr)
612 {
613 struct rasops_info *ri = cookie;
614 struct vcons_screen *scr = ri->ri_hw;
615 int pos;
616
617 if ((row >= 0) && (row < ri->ri_rows) && (col >= 0) &&
618 (col < ri->ri_cols)) {
619 pos = col + row * ri->ri_cols;
620 scr->scr_attrs[pos] = attr;
621 scr->scr_chars[pos] = c;
622 }
623 }
624
625 static void
626 vcons_putchar(void *cookie, int row, int col, u_int c, long attr)
627 {
628 struct rasops_info *ri = cookie;
629 struct vcons_screen *scr = ri->ri_hw;
630
631 vcons_putchar_buffer(cookie, row, col, c, attr);
632
633 vcons_lock(scr);
634 if (SCREEN_IS_VISIBLE(scr) && SCREEN_CAN_DRAW(scr)) {
635 scr->scr_vd->putchar(cookie, row, col, c, attr);
636 }
637 vcons_unlock(scr);
638 }
639
640 static void
641 vcons_cursor(void *cookie, int on, int row, int col)
642 {
643 struct rasops_info *ri = cookie;
644 struct vcons_screen *scr = ri->ri_hw;
645
646 vcons_lock(scr);
647 if (SCREEN_IS_VISIBLE(scr) && SCREEN_CAN_DRAW(scr)) {
648 scr->scr_vd->cursor(cookie, on, row, col);
649 } else {
650 scr->scr_ri.ri_crow = row;
651 scr->scr_ri.ri_ccol = col;
652 }
653 vcons_unlock(scr);
654 }
655
656 /* methods to read/write characters via ioctl() */
657
658 static int
659 vcons_putwschar(struct vcons_screen *scr, struct wsdisplay_char *wsc)
660 {
661 long attr;
662 struct rasops_info *ri;
663
664 KASSERT(scr != NULL && wsc != NULL);
665
666 ri = &scr->scr_ri;
667
668 if (__predict_false((unsigned int)wsc->col > ri->ri_cols ||
669 (unsigned int)wsc->row > ri->ri_rows))
670 return (EINVAL);
671
672 ri->ri_ops.allocattr(ri, wsc->foreground, wsc->background,
673 wsc->flags, &attr);
674 vcons_putchar(ri, wsc->row, wsc->col, wsc->letter, attr);
675 return 0;
676 }
677
678 static int
679 vcons_getwschar(struct vcons_screen *scr, struct wsdisplay_char *wsc)
680 {
681 int offset;
682 long attr;
683 struct rasops_info *ri;
684
685 KASSERT(scr != NULL && wsc != NULL);
686
687 ri = &scr->scr_ri;
688 offset = ri->ri_cols * wsc->row + wsc->col;
689 wsc->letter = scr->scr_chars[offset];
690 attr = scr->scr_attrs[offset];
691
692 /*
693 * this is ugly. We need to break up an attribute into colours and
694 * flags but there's no rasops method to do that so we must rely on
695 * the 'canonical' encoding.
696 */
697 wsc->foreground = (attr & 0xff000000) >> 24;
698 wsc->background = (attr & 0x00ff0000) >> 16;
699 wsc->flags = (attr & 0x0000ff00) >> 8;
700 return 0;
701 }
702