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lunafb.c revision 1.43
      1 /* $NetBSD: lunafb.c,v 1.43 2021/08/07 16:18:57 thorpej Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2000 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Tohru Nishimura.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
     33 
     34 __KERNEL_RCSID(0, "$NetBSD: lunafb.c,v 1.43 2021/08/07 16:18:57 thorpej Exp $");
     35 
     36 #include <sys/param.h>
     37 #include <sys/systm.h>
     38 #include <sys/conf.h>
     39 #include <sys/device.h>
     40 #include <sys/ioctl.h>
     41 #include <sys/kmem.h>
     42 #include <sys/mman.h>
     43 #include <sys/proc.h>
     44 #include <sys/tty.h>
     45 #include <sys/errno.h>
     46 #include <sys/buf.h>
     47 
     48 #include <uvm/uvm_extern.h>
     49 
     50 #include <dev/wscons/wsconsio.h>
     51 #include <dev/wscons/wsdisplayvar.h>
     52 #include <dev/rasops/rasops.h>
     53 
     54 #include <machine/cpu.h>
     55 #include <machine/autoconf.h>
     56 
     57 #include <arch/luna68k/dev/omrasopsvar.h>
     58 
     59 #include "ioconf.h"
     60 
     61 struct bt454 {
     62 	volatile uint8_t bt_addr;	/* map address register */
     63 	volatile uint8_t bt_cmap;	/* colormap data register */
     64 };
     65 
     66 struct bt458 {
     67 	volatile uint8_t bt_addr;	/* map address register */
     68 	uint8_t          pad0[3];
     69 	volatile uint8_t bt_cmap;	/* colormap data register */
     70 	uint8_t          pad1[3];
     71 	volatile uint8_t bt_ctrl;	/* control register */
     72 	uint8_t          pad2[3];
     73 	volatile uint8_t bt_omap;	/* overlay (cursor) map register */
     74 	uint8_t          pad3[3];
     75 };
     76 
     77 #define	OMFB_RFCNT	BMAP_RFCNT	/* video h-origin/v-origin */
     78 #define	OMFB_RAMDAC	BMAP_PALLET2	/* Bt454/Bt458 RAMDAC */
     79 
     80 #define	OMFB_SIZE	(BMAP_FN0 - BMAP_BMP + PAGE_SIZE)
     81 
     82 struct hwcmap {
     83 #define CMAP_SIZE 256
     84 	uint8_t r[CMAP_SIZE];
     85 	uint8_t g[CMAP_SIZE];
     86 	uint8_t b[CMAP_SIZE];
     87 };
     88 
     89 static const struct {
     90 	uint8_t r;
     91 	uint8_t g;
     92 	uint8_t b;
     93 } ansicmap[16] = {
     94 	{    0,    0,    0},
     95 	{ 0x80,    0,    0},
     96 	{    0, 0x80,    0},
     97 	{ 0x80, 0x80,    0},
     98 	{    0,    0, 0x80},
     99 	{ 0x80,    0, 0x80},
    100 	{    0, 0x80, 0x80},
    101 	{ 0xc0, 0xc0, 0xc0},
    102 	{ 0x80, 0x80, 0x80},
    103 	{ 0xff,    0,    0},
    104 	{    0, 0xff,    0},
    105 	{ 0xff, 0xff,    0},
    106 	{    0,    0, 0xff},
    107 	{ 0xff,    0, 0xff},
    108 	{    0, 0xff, 0xff},
    109 	{ 0xff, 0xff, 0xff},
    110 };
    111 
    112 struct om_hwdevconfig {
    113 	int	dc_wid;			/* width of frame buffer */
    114 	int	dc_ht;			/* height of frame buffer */
    115 	int	dc_depth;		/* depth, bits per pixel */
    116 	int	dc_rowbytes;		/* bytes in a FB scan line */
    117 	int	dc_cmsize;		/* colormap size */
    118 	struct hwcmap dc_cmap;		/* software copy of colormap */
    119 	vaddr_t	dc_videobase;		/* base of flat frame buffer */
    120 	struct rasops_info dc_ri;	/* raster blitter variables */
    121 };
    122 
    123 struct omfb_softc {
    124 	device_t sc_dev;		/* base device */
    125 	struct om_hwdevconfig *sc_dc;	/* device configuration */
    126 	int sc_nscreens;
    127 	int sc_mode;
    128 };
    129 
    130 static int  omgetcmap(struct omfb_softc *, struct wsdisplay_cmap *);
    131 static int  omsetcmap(struct omfb_softc *, struct wsdisplay_cmap *);
    132 
    133 static struct om_hwdevconfig omfb_console_dc;
    134 static void omfb_resetcmap(struct om_hwdevconfig *);
    135 static void omfb_getdevconfig(paddr_t, struct om_hwdevconfig *);
    136 
    137 static struct wsscreen_descr omfb_stdscreen = {
    138 	.name = "std"
    139 };
    140 
    141 static const struct wsscreen_descr *_omfb_scrlist[] = {
    142 	&omfb_stdscreen,
    143 };
    144 
    145 static const struct wsscreen_list omfb_screenlist = {
    146 	sizeof(_omfb_scrlist) / sizeof(struct wsscreen_descr *), _omfb_scrlist
    147 };
    148 
    149 static int   omfbioctl(void *, void *, u_long, void *, int, struct lwp *);
    150 static paddr_t omfbmmap(void *, void *, off_t, int);
    151 static int   omfb_alloc_screen(void *, const struct wsscreen_descr *,
    152 			       void **, int *, int *, long *);
    153 static void  omfb_free_screen(void *, void *);
    154 static int   omfb_show_screen(void *, void *, int,
    155 			      void (*) (void *, int, int), void *);
    156 
    157 static const struct wsdisplay_accessops omfb_accessops = {
    158 	.ioctl        = omfbioctl,
    159 	.mmap         = omfbmmap,
    160 	.alloc_screen = omfb_alloc_screen,
    161 	.free_screen  = omfb_free_screen,
    162 	.show_screen  = omfb_show_screen,
    163 	.load_font    = NULL,
    164 	.pollc        = NULL,
    165 	.scroll       = NULL
    166 };
    167 
    168 static int  omfbmatch(device_t, cfdata_t, void *);
    169 static void omfbattach(device_t, device_t, void *);
    170 
    171 CFATTACH_DECL_NEW(fb, sizeof(struct omfb_softc),
    172     omfbmatch, omfbattach, NULL, NULL);
    173 
    174 extern int hwplanemask;	/* hardware planemask; retrieved at boot */
    175 
    176 static int omfb_console;
    177 int  omfb_cnattach(void);
    178 
    179 static int
    180 omfbmatch(device_t parent, cfdata_t cf, void *aux)
    181 {
    182 	struct mainbus_attach_args *ma = aux;
    183 
    184 	if (strcmp(ma->ma_name, fb_cd.cd_name))
    185 		return 0;
    186 #if 0	/* XXX badaddr() bombs if no framebuffer is installed */
    187 	if (badaddr((void *)ma->ma_addr, 4))
    188 		return 0;
    189 #else
    190 	if (hwplanemask == 0)
    191 		return 0;
    192 #endif
    193 	return 1;
    194 }
    195 
    196 static void
    197 omfbattach(device_t parent, device_t self, void *args)
    198 {
    199 	struct omfb_softc *sc = device_private(self);
    200 	struct wsemuldisplaydev_attach_args waa;
    201 
    202 	sc->sc_dev = self;
    203 
    204 	if (omfb_console) {
    205 		sc->sc_dc = &omfb_console_dc;
    206 		sc->sc_nscreens = 1;
    207 	} else {
    208 		sc->sc_dc = kmem_zalloc(sizeof(struct om_hwdevconfig),
    209 		    KM_SLEEP);
    210 		omfb_getdevconfig(OMFB_FB_WADDR, sc->sc_dc);
    211 	}
    212 	aprint_normal(": %d x %d, %dbpp\n", sc->sc_dc->dc_wid, sc->sc_dc->dc_ht,
    213 	    sc->sc_dc->dc_depth);
    214 
    215 	sc->sc_mode = WSDISPLAYIO_MODE_EMUL;
    216 	waa.console = omfb_console;
    217 	waa.scrdata = &omfb_screenlist;
    218 	waa.accessops = &omfb_accessops;
    219 	waa.accesscookie = sc;
    220 
    221 	config_found(self, &waa, wsemuldisplaydevprint, CFARGS_NONE);
    222 }
    223 
    224 /* EXPORT */ int
    225 omfb_cnattach(void)
    226 {
    227 	struct om_hwdevconfig *dc = &omfb_console_dc;
    228 	struct rasops_info *ri = &dc->dc_ri;
    229 	long defattr;
    230 
    231 	omfb_getdevconfig(OMFB_FB_WADDR, dc);
    232 	(*ri->ri_ops.allocattr)(ri, 0, 0, 0, &defattr);
    233 	wsdisplay_cnattach(&omfb_stdscreen, ri, 0, 0, defattr);
    234 	omfb_console = 1;
    235 	return 0;
    236 }
    237 
    238 static int
    239 omfbioctl(void *v, void *vs, u_long cmd, void *data, int flag, struct lwp *l)
    240 {
    241 	struct omfb_softc *sc = v;
    242 	struct om_hwdevconfig *dc = sc->sc_dc;
    243 	int new_mode;
    244 
    245 	switch (cmd) {
    246 	case WSDISPLAYIO_GTYPE:
    247 		*(u_int *)data = WSDISPLAY_TYPE_LUNA;
    248 		return 0;
    249 
    250 	case WSDISPLAYIO_GINFO:
    251 #define	wsd_fbip ((struct wsdisplay_fbinfo *)data)
    252 		wsd_fbip->height = dc->dc_ht;
    253 		wsd_fbip->width = dc->dc_wid;
    254 		wsd_fbip->depth = dc->dc_depth;
    255 		wsd_fbip->cmsize = dc->dc_cmsize;
    256 #undef fbt
    257 		return 0;
    258 
    259 	case WSDISPLAYIO_LINEBYTES:
    260 		*(u_int *)data = dc->dc_rowbytes;
    261 		return 0;
    262 
    263 	case WSDISPLAYIO_GETCMAP:
    264 		return omgetcmap(sc, (struct wsdisplay_cmap *)data);
    265 
    266 	case WSDISPLAYIO_PUTCMAP:
    267 		return omsetcmap(sc, (struct wsdisplay_cmap *)data);
    268 
    269 	case WSDISPLAYIO_SMODE:
    270 		new_mode = *(int *)data;
    271 		if (new_mode != sc->sc_mode) {
    272 			sc->sc_mode = new_mode;
    273 			if (new_mode == WSDISPLAYIO_MODE_EMUL)
    274 				omfb_resetcmap(dc);
    275 		}
    276 		return 0;
    277 
    278 	case WSDISPLAYIO_SVIDEO:
    279 	case WSDISPLAYIO_GVIDEO:
    280 	case WSDISPLAYIO_GCURPOS:
    281 	case WSDISPLAYIO_SCURPOS:
    282 	case WSDISPLAYIO_GCURMAX:
    283 	case WSDISPLAYIO_GCURSOR:
    284 	case WSDISPLAYIO_SCURSOR:
    285 		break;
    286 	}
    287 	return EPASSTHROUGH;
    288 }
    289 
    290 /*
    291  * Return the address that would map the given device at the given
    292  * offset, allowing for the given protection, or return -1 for error.
    293  */
    294 static paddr_t
    295 omfbmmap(void *v, void *vs, off_t offset, int prot)
    296 {
    297 	struct omfb_softc *sc = v;
    298 	struct om_hwdevconfig *dc = sc->sc_dc;
    299 	paddr_t cookie = -1;
    300 
    301 	switch (sc->sc_mode) {
    302 #if 0
    303 	case WSDISPLAYIO_MODE_MAPPED:
    304 		if (offset >= 0 && offset < OMFB_SIZE)
    305 			cookie = m68k_btop(m68k_trunc_page(dc->dc_videobase) +
    306 			    offset);
    307 		break;
    308 #endif
    309 	case WSDISPLAYIO_MODE_DUMBFB:
    310 		if (offset >= 0 &&
    311 		    offset < m68k_page_offset(OMFB_FB_RADDR) +
    312 		    dc->dc_rowbytes * dc->dc_ht * dc->dc_depth)
    313 			cookie = m68k_btop(m68k_trunc_page(OMFB_FB_RADDR) +
    314 			    offset);
    315 		break;
    316 	}
    317 
    318 	return cookie;
    319 }
    320 
    321 static int
    322 omgetcmap(struct omfb_softc *sc, struct wsdisplay_cmap *p)
    323 {
    324 	u_int index = p->index, count = p->count;
    325 	int cmsize, error;
    326 
    327 	cmsize = sc->sc_dc->dc_cmsize;
    328 	if (index >= cmsize || count > cmsize - index)
    329 		return EINVAL;
    330 
    331 	error = copyout(&sc->sc_dc->dc_cmap.r[index], p->red, count);
    332 	if (error)
    333 		return error;
    334 	error = copyout(&sc->sc_dc->dc_cmap.g[index], p->green, count);
    335 	if (error)
    336 		return error;
    337 	error = copyout(&sc->sc_dc->dc_cmap.b[index], p->blue, count);
    338 	return error;
    339 }
    340 
    341 static int
    342 omsetcmap(struct omfb_softc *sc, struct wsdisplay_cmap *p)
    343 {
    344 	struct hwcmap cmap;
    345 	u_int index = p->index, count = p->count;
    346 	int cmsize, i, error;
    347 
    348 	cmsize = sc->sc_dc->dc_cmsize;
    349 	if (index >= cmsize || count > cmsize - index)
    350 		return EINVAL;
    351 
    352 	error = copyin(p->red, &cmap.r[index], count);
    353 	if (error)
    354 		return error;
    355 	error = copyin(p->green, &cmap.g[index], count);
    356 	if (error)
    357 		return error;
    358 	error = copyin(p->blue, &cmap.b[index], count);
    359 	if (error)
    360 		return error;
    361 
    362 	memcpy(&sc->sc_dc->dc_cmap.r[index], &cmap.r[index], count);
    363 	memcpy(&sc->sc_dc->dc_cmap.g[index], &cmap.g[index], count);
    364 	memcpy(&sc->sc_dc->dc_cmap.b[index], &cmap.b[index], count);
    365 	if (hwplanemask == 0x0f) {
    366 		struct bt454 *odac = (struct bt454 *)OMFB_RAMDAC;
    367 		odac->bt_addr = index;
    368 		for (i = index; i < index + count; i++) {
    369 			odac->bt_cmap = sc->sc_dc->dc_cmap.r[i];
    370 			odac->bt_cmap = sc->sc_dc->dc_cmap.g[i];
    371 			odac->bt_cmap = sc->sc_dc->dc_cmap.b[i];
    372 		}
    373 	} else if (hwplanemask == 0xff) {
    374 		struct bt458 *ndac = (struct bt458 *)OMFB_RAMDAC;
    375 		ndac->bt_addr = index;
    376 		for (i = index; i < index + count; i++) {
    377 			ndac->bt_cmap = sc->sc_dc->dc_cmap.r[i];
    378 			ndac->bt_cmap = sc->sc_dc->dc_cmap.g[i];
    379 			ndac->bt_cmap = sc->sc_dc->dc_cmap.b[i];
    380 		}
    381 	}
    382 	return 0;
    383 }
    384 
    385 static void
    386 omfb_resetcmap(struct om_hwdevconfig *dc)
    387 {
    388 	int i;
    389 
    390 	if (hwplanemask == 0x01) {
    391 		struct bt454 *odac = (struct bt454 *)OMFB_RAMDAC;
    392 
    393 		/*
    394 		 * On 1bpp framebuffer, only plane P0 has framebuffer memory
    395 		 * and other planes seems pulled up, i.e. always 1.
    396 		 * Set white only for a palette (P0,P1,P2,P3) = (1,1,1,1).
    397 		 */
    398 		odac->bt_addr = 0;
    399 		for (i = 0; i < 15; i++) {
    400 			odac->bt_cmap = dc->dc_cmap.r[i] = 0;
    401 			odac->bt_cmap = dc->dc_cmap.g[i] = 0;
    402 			odac->bt_cmap = dc->dc_cmap.b[i] = 0;
    403 		}
    404 		/*
    405 		 * The B/W video connector is connected to IOG of Bt454,
    406 		 * and IOR and IOB are unused.
    407 		 */
    408 		odac->bt_cmap = dc->dc_cmap.r[15] = 0;
    409 		odac->bt_cmap = dc->dc_cmap.g[15] = 255;
    410 		odac->bt_cmap = dc->dc_cmap.b[15] = 0;
    411 	} else if (hwplanemask == 0x0f) {
    412 		struct bt454 *odac = (struct bt454 *)OMFB_RAMDAC;
    413 
    414 		odac->bt_addr = 0;
    415 		for (i = 0; i < 16; i++) {
    416 			odac->bt_cmap = dc->dc_cmap.r[i] = ansicmap[i].r;
    417 			odac->bt_cmap = dc->dc_cmap.g[i] = ansicmap[i].g;
    418 			odac->bt_cmap = dc->dc_cmap.b[i] = ansicmap[i].b;
    419 		}
    420 	} else if (hwplanemask == 0xff) {
    421 		struct bt458 *ndac = (struct bt458 *)OMFB_RAMDAC;
    422 
    423 		/*
    424 		 * Initialize the Bt458.  When we write to control registers,
    425 		 * the address is not incremented automatically. So we specify
    426 		 * it ourselves for each control register.
    427 		 */
    428 		ndac->bt_addr = 0x04;
    429 		ndac->bt_ctrl = 0xff; /* all planes will be read */
    430 		ndac->bt_addr = 0x05;
    431 		ndac->bt_ctrl = 0x00; /* all planes have non-blink */
    432 		ndac->bt_addr = 0x06;
    433 		ndac->bt_ctrl = 0x40; /* pallete enabled, ovly plane disabled */
    434 		ndac->bt_addr = 0x07;
    435 		ndac->bt_ctrl = 0x00; /* no test mode */
    436 
    437 		/*
    438 		 * Set ANSI 16 colors.  We only supports 4bpp console right
    439 		 * now, repeat 16 colors in 256 colormap.
    440 		 */
    441 		ndac->bt_addr = 0;
    442 		for (i = 0; i < 256; i++) {
    443 			ndac->bt_cmap = dc->dc_cmap.r[i] = ansicmap[i % 16].r;
    444 			ndac->bt_cmap = dc->dc_cmap.g[i] = ansicmap[i % 16].g;
    445 			ndac->bt_cmap = dc->dc_cmap.b[i] = ansicmap[i % 16].b;
    446 		}
    447 	}
    448 }
    449 
    450 static void
    451 omfb_getdevconfig(paddr_t paddr, struct om_hwdevconfig *dc)
    452 {
    453 	int bpp, i;
    454 	struct rasops_info *ri;
    455 	union {
    456 		struct { short h, v; } p;
    457 		uint32_t u;
    458 	} rfcnt;
    459 
    460 	switch (hwplanemask) {
    461 	case 0xff:
    462 		bpp = 8;	/* XXX check monochrome bit in DIPSW */
    463 		break;
    464 	default:
    465 	case 0x0f:
    466 		bpp = 4;	/* XXX check monochrome bit in DIPSW */
    467 		break;
    468 	case 1:
    469 		bpp = 1;
    470 		break;
    471 	}
    472 	dc->dc_wid = 1280;
    473 	dc->dc_ht = 1024;
    474 	dc->dc_depth = bpp;
    475 	dc->dc_rowbytes = 2048 / 8;
    476 	dc->dc_cmsize = (bpp == 1) ? 0 : 1 << bpp;
    477 	dc->dc_videobase = paddr;
    478 
    479 	omfb_resetcmap(dc);
    480 
    481 	/* adjust h/v origin on screen */
    482 	rfcnt.p.h = 7;
    483 	rfcnt.p.v = -27;
    484 	/* single write of 0x007ffe6 */
    485 	*(volatile uint32_t *)OMFB_RFCNT = rfcnt.u;
    486 
    487 	/* clear the screen */
    488 	*(volatile uint32_t *)OMFB_PLANEMASK = 0xff;
    489 	((volatile uint32_t *)OMFB_ROPFUNC)[5] = ~0;	/* ROP copy */
    490 	for (i = 0; i < dc->dc_ht * dc->dc_rowbytes / sizeof(uint32_t); i++)
    491 		*((volatile uint32_t *)dc->dc_videobase + i) = 0;
    492 	*(volatile uint32_t *)OMFB_PLANEMASK = 0x01;
    493 
    494 	/* initialize the raster */
    495 	ri = &dc->dc_ri;
    496 	ri->ri_width = dc->dc_wid;
    497 	ri->ri_height = dc->dc_ht;
    498 	ri->ri_depth = 1;       /* since planes are independently addressed */
    499 	ri->ri_stride = dc->dc_rowbytes;
    500 	ri->ri_bits = (void *)dc->dc_videobase;
    501 	ri->ri_flg = RI_CENTER;
    502 	if (dc == &omfb_console_dc)
    503 		ri->ri_flg |= RI_NO_AUTO;
    504 	ri->ri_hw = dc;
    505 
    506 	if (bpp == 4 || bpp == 8)
    507 		omrasops4_init(ri, 34, 80);
    508 	else
    509 		omrasops1_init(ri, 34, 80);
    510 
    511 	omfb_stdscreen.nrows = ri->ri_rows;
    512 	omfb_stdscreen.ncols = ri->ri_cols;
    513 	omfb_stdscreen.textops = &ri->ri_ops;
    514 	omfb_stdscreen.capabilities = ri->ri_caps;
    515 	omfb_stdscreen.fontwidth = ri->ri_font->fontwidth;
    516 	omfb_stdscreen.fontheight = ri->ri_font->fontheight;
    517 }
    518 
    519 static int
    520 omfb_alloc_screen(void *v, const struct wsscreen_descr *type, void **cookiep,
    521     int *curxp, int *curyp, long *attrp)
    522 {
    523 	struct omfb_softc *sc = v;
    524 	struct rasops_info *ri = &sc->sc_dc->dc_ri;
    525 
    526 	if (sc->sc_nscreens > 0)
    527 		return ENOMEM;
    528 
    529 	*cookiep = ri;
    530 	*curxp = 0;
    531 	*curyp = 0;
    532 	(*ri->ri_ops.allocattr)(ri, 0, 0, 0, attrp);
    533 	sc->sc_nscreens++;
    534 	return 0;
    535 }
    536 
    537 static void
    538 omfb_free_screen(void *v, void *cookie)
    539 {
    540 	struct omfb_softc *sc = v;
    541 
    542 	if (sc->sc_dc == &omfb_console_dc)
    543 		panic("omfb_free_screen: console");
    544 
    545 	sc->sc_nscreens--;
    546 }
    547 
    548 static int
    549 omfb_show_screen(void *v, void *cookie, int waitok,
    550     void (*cb)(void *, int, int), void *cbarg)
    551 {
    552 
    553 	return 0;
    554 }
    555