xref: /haiku/src/add-ons/kernel/drivers/graphics/vesa/patch.cpp (revision 52f7c9389475e19fc21487b38064b4390eeb6fea)
1 /*
2  * Copyright 2021, Adrien Destugues, pulkomandy@pulkomandy.tk
3  * Distributed under the terms of the MIT License.
4  */
5 
6 
7 #include "vesa_private.h"
8 #include "vesa.h"
9 
10 #include <SupportDefs.h>
11 
12 #define _GNU_SOURCE
13 #include <string.h>
14 
15 #include "atombios.h"
16 #include "driver.h"
17 #include "edid_raw.h"
18 #include "utility.h"
19 #include "vesa_info.h"
20 
21 
22 extern bios_module_info* sBIOSModule;
23 
24 
25 status_t
26 vbe_patch_intel_bios(bios_state* state, display_mode& mode)
27 {
28 	edid1_detailed_timing_raw timing;
29 
30 	timing.pixel_clock = mode.timing.pixel_clock / 10;
31 
32 	timing.h_active = mode.timing.h_display & 0xFF;
33 	timing.h_active_high = (mode.timing.h_display >> 8) & 0xF;
34 
35 	uint16 h_blank = mode.timing.h_total - mode.timing.h_display;
36 	timing.h_blank = h_blank & 0xff;
37 	timing.h_blank_high = (h_blank >> 8) & 0xF;
38 
39 	timing.v_active = mode.timing.v_display & 0xFF;
40 	timing.v_active_high = (mode.timing.v_display >> 8) & 0xF;
41 
42 	uint16 v_blank = mode.timing.v_total - mode.timing.v_display;
43 	timing.v_blank = v_blank & 0xff;
44 	timing.v_blank_high = (v_blank >> 8) & 0xF;
45 
46 	uint16 h_sync_off = mode.timing.h_sync_start - mode.timing.h_display;
47 	timing.h_sync_off = h_sync_off & 0xFF;
48 	timing.h_sync_off_high = (h_sync_off >> 8) & 0x3;
49 
50 	uint16 h_sync_width = mode.timing.h_sync_end - mode.timing.h_sync_start;
51 	timing.h_sync_width = h_sync_width & 0xFF;
52 	timing.h_sync_width_high = (h_sync_width >> 8) & 0x3;
53 
54 	uint16 v_sync_off = mode.timing.v_sync_start - mode.timing.v_display;
55 	timing.v_sync_off = v_sync_off & 0xF;
56 	timing.v_sync_off_high = (v_sync_off >> 4) & 0x3;
57 
58 	uint16 v_sync_width = mode.timing.v_sync_end - mode.timing.v_sync_start;
59 	timing.v_sync_width = v_sync_width & 0xF;
60 	timing.v_sync_width_high = (v_sync_width >> 4) & 0x3;
61 
62 	timing.h_size = 0;
63 	timing.v_size = 0;
64 	timing.h_size_high = 0;
65 	timing.v_size_high = 0;
66 	timing.h_border = 0;
67 	timing.v_border = 0;
68 	timing.interlaced = 0;
69 	timing.stereo = 0;
70 	timing.sync = 3;
71 	timing.misc = 0;
72 	timing.stereo_il = 0;
73 
74 	static const uint8 knownMode[] = { 0x64, 0x19, 0x00, 0x40, 0x41, 0x00, 0x26, 0x30, 0x18,
75 		0x88, 0x36, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x18};
76 		// This is the EDID description for a standard 1024x768 timing. We will find and replace
77 		// all occurences of it in the BIOS with our custom mode.
78 
79 	// Get a pointer to the BIOS
80 	const uintptr_t kBiosBase = 0xc0000;
81 	const size_t kBiosSize = 0x10000;
82 	uint8_t* bios = (uint8_t*)sBIOSModule->virtual_address(state, kBiosBase);
83 	uint8_t* biosEnd = bios + kBiosSize;
84 
85 	int replacementCount = 0;
86 	while (bios < biosEnd) {
87 		bios = (uint8_t*)memmem(bios, biosEnd - bios, knownMode, sizeof(knownMode));
88 		if (bios == NULL)
89 			break;
90 		memcpy(bios, &timing, sizeof(timing));
91 		bios += sizeof(timing);
92 		replacementCount++;
93 	}
94 
95 	dprintf(DEVICE_NAME ": patched custom mode in %d locations\n", replacementCount);
96 
97 	// Did we manage to find a mode descriptor to replace?
98 	if (replacementCount == 0)
99 		return B_NOT_SUPPORTED;
100 	return B_OK;
101 }
102 
103 
104 status_t
105 vbe_patch_nvidia_bios(bios_state* state, display_mode& mode)
106 {
107 	struct nvidia_mode {
108 		uint32 width;
109 		uint32 height;
110 		uint8 patch0[17];
111 		uint8 patch1[9];
112 		uint8 patch2[13];
113 		uint8 patch3[5];
114 	};
115 
116 	static const nvidia_mode allowedModes[] = {
117 		{1280,  720, {0x16, 0xCB, 0x9F, 0x9F, 0x8F, 0xA7, 0x17, 0xEA, 0xD2, 0xCF, 0xCF, 0xEB, 0x47,
118 				0xE0, 0xC0, 0x00, 0x01},
119 			{0x00, 0x05, 0xD0, 0x02, 0xA0, 0x2C, 0x10, 0x07, 0x05},
120 			{0x7B, 0x01, 0x03, 0x7B, 0x01, 0x08, 0x01, 0x20, 0x80, 0x02, 0xFF, 0xFF, 0x20},
121 			{0x00, 0x05, 0xBA, 0xD0, 0x02}},
122 		{1280,  800, {0x12, 0xCD, 0x9F, 0x9F, 0x91, 0xA9, 0x1A, 0x3A, 0x21, 0x1F, 0x1F, 0x3B, 0x44,
123 				0xFE, 0xC0, 0x00, 0x01},
124 			{0x00, 0x05, 0x20, 0x03, 0xA0, 0x32, 0x10, 0x23, 0x05},
125 			{0x61, 0x01, 0x03, 0x61, 0x01, 0x08, 0x01, 0x20, 0x80, 0x02, 0xFF, 0xFF, 0x20},
126 			{0x00, 0x05, 0xBA, 0x20, 0x03}},
127 		{1360,  768, {0x16, 0xB9, 0xA9, 0x9F, 0x8F, 0xB2, 0x16, 0x14, 0x01, 0xFF, 0xCF, 0xEB, 0x46,
128 				0xEA, 0xC0, 0x00, 0x01},
129 			{0x50, 0x05, 0x00, 0x03, 0xAA, 0x2F, 0x10, 0x07, 0x05},
130 			{0x4D, 0x01, 0x03, 0x4D, 0x01, 0x08, 0x01, 0x20, 0xA8, 0x02, 0xFF, 0xFF, 0x20},
131 			{0x50, 0x05, 0xBA, 0x00, 0x03}},
132 		{1400, 1050, {0x12, 0xE6, 0xAE, 0xAE, 0x8A, 0xBB, 0x8E, 0x3D, 0x1B, 0x19, 0x19, 0x3E, 0x0E,
133 				0x00, 0xC0, 0x24, 0x12},
134 			{0x78, 0x05, 0x1A, 0x04, 0xAF, 0x4A, 0x0E, 0x21, 0x05},
135 			{0x49, 0x01, 0x03, 0x49, 0x01, 0x08, 0x01, 0x20, 0xBC, 0x02, 0xFF, 0xFF, 0x20},
136 			{0x78, 0x05, 0xBA, 0x1A, 0x04}},
137 		{1440,  900, {0x12, 0xE9, 0xB3, 0xB3, 0x8D, 0xBF, 0x92, 0xA3, 0x85, 0x83, 0x83, 0xA4, 0x48,
138 				0xFE, 0xC0, 0x00, 0x00},
139 			{0xA0, 0x05, 0x84, 0x03, 0xB4, 0x38, 0x10, 0x24, 0x05},
140 			{0x65, 0x01, 0x03, 0x65, 0x01, 0x08, 0x01, 0x20, 0xD0, 0x02, 0xFF, 0xFF, 0x20},
141 			{0xA0, 0x05, 0xBA, 0x84, 0x03}},
142 		{1600,  900, {0x1A, 0xD7, 0xC7, 0xC7, 0x9B, 0xCD, 0x11, 0x9C, 0x86, 0x83, 0x83, 0x9D, 0x4B,
143 				0xFE, 0xC0, 0x00, 0x00},
144 			{0x40, 0x06, 0x84, 0x03, 0xC8, 0x38, 0x10, 0x27, 0x05},
145 			{0x67, 0x01, 0x03, 0x67, 0x01, 0x08, 0x01, 0x20, 0x20, 0x03, 0xFF, 0xFF, 0x20},
146 			{0x40, 0x06, 0xBA, 0x84, 0x03}},
147 		{1600, 1200, {0x12, 0x03, 0xC7, 0xC7, 0x87, 0xD1, 0x09, 0xE0, 0xB1, 0xAF, 0xAF, 0xE1, 0x04,
148 				0x00, 0x01, 0x24, 0x13},
149 			{0x40, 0x06, 0xB0, 0x04, 0xC8, 0x4A, 0x10, 0x19, 0x05},
150 			{0x4A, 0x01, 0x03, 0x4A, 0x01, 0x08, 0x01, 0x20, 0x20, 0x03, 0xFF, 0xFF, 0x20},
151 			{0x40, 0x06, 0xBA, 0xB0, 0x04}},
152 		{1680, 1050, {0x12, 0x15, 0xD1, 0xD1, 0x99, 0xE0, 0x17, 0x3D, 0x1B, 0x19, 0x19, 0x3E, 0x0E,
153 				0x00, 0x01, 0x24, 0x13},
154 			{0x90, 0x06, 0x1A, 0x04, 0xD2, 0x41, 0x10, 0x25, 0x05},
155 			{0x69, 0x01, 0x03, 0x69, 0x01, 0x08, 0x01, 0x20, 0x48, 0x03, 0xFF, 0xFF, 0x20},
156 			{0x90, 0x06, 0xBA, 0x1A, 0x04}},
157 		{1920, 1080, {0x16, 0x0E, 0xEF, 0x9F, 0x8F, 0xFD, 0x02, 0x63, 0x3B, 0x37, 0xCF, 0xEB, 0x40,
158 				0x00, 0xC1, 0x24, 0x02},
159 			{0x80, 0x07, 0x38, 0x04, 0xF0, 0x42, 0x10, 0x07, 0x05},
160 			{0x4D, 0x01, 0x03, 0x4D, 0x01, 0x08, 0x01, 0x20, 0xC0, 0x03, 0xFF, 0xFF, 0x20},
161 			{0x80, 0x07, 0xBA, 0x38, 0x04}},
162 		{1920, 1200, {0x12, 0x3F, 0xEF, 0xEF, 0x83, 0x01, 0x1B, 0xD8, 0xB1, 0xAF, 0xAF, 0xD9, 0x04,
163 				0x00, 0x41, 0x25, 0x12},
164 			{0x80, 0x07, 0xB0, 0x04, 0xF0, 0x4B, 0x10, 0x26, 0x05},
165 			{0x7D, 0x01, 0x03, 0x7D, 0x01, 0x08, 0x01, 0x20, 0xC0, 0x03, 0xFF, 0xFF, 0x20},
166 			{0x80, 0x07, 0xBA, 0xB0, 0x04}},
167 		{2048, 1536, {0x12, 0x63, 0xFF, 0xFF, 0x9D, 0x12, 0x0E, 0x34, 0x01, 0x00, 0x00, 0x35, 0x44,
168 				0xE0, 0x41, 0x25, 0x13},
169 			{0x00, 0x08, 0x00, 0x06, 0x00, 0x60, 0x10, 0x22, 0x05},
170 			{0x7A, 0x01, 0x03, 0x52, 0x01, 0x08, 0x01, 0x20, 0x00, 0x04, 0xFF, 0xFF, 0x20},
171 			{0x00, 0x08, 0xBA, 0x00, 0x06}}
172 	};
173 
174 	static const nvidia_mode knownMode = { 0, 0,
175 		{0x34, 0x2d, 0x27, 0x28, 0x90, 0x2b, 0xa0, 0xbf, 0x9c, 0x8f, 0x96, 0xb9, 0x8e, 0x1f, 0x00,
176 			0x00, 0x00},
177 		{0x28, 0x00, 0x19, 0x00, 0x28, 0x18, 0x08, 0x08, 0x05},
178 		{0x82, 0x0f, 0x03, 0x01, 0x00, 0x00, 0x08, 0x04, 0x14, 0x00, 0x00, 0x08, 0x17},
179 		{0x40, 0x06, 0xba, 0xb0, 0x04}
180 	};
181 
182 	size_t i;
183 	for (i = 0; i < B_COUNT_OF(allowedModes); i++) {
184 		if (allowedModes[i].width == mode.timing.h_display
185 			&& allowedModes[i].height == mode.timing.v_display) {
186 			break;
187 		}
188 	}
189 
190 	if (i >= B_COUNT_OF(allowedModes))
191 		return B_BAD_VALUE;
192 
193 	// Get a pointer to the BIOS
194 	const uintptr_t kBiosBase = 0xc0000;
195 	const size_t kBiosSize = 0x10000;
196 	uint8_t* biosBase = (uint8_t*)sBIOSModule->virtual_address(state, kBiosBase);
197 	uint8_t* biosEnd = biosBase + kBiosSize;
198 
199 	int replacementCount = 0;
200 	uint8_t* bios = biosBase;
201 	while (bios < biosEnd) {
202 		bios = (uint8_t*)memmem(bios, biosEnd - bios, knownMode.patch0, sizeof(knownMode.patch0));
203 		if (bios == NULL)
204 			break;
205 		memcpy(bios, allowedModes[i].patch0, sizeof(allowedModes[i].patch0));
206 		bios += sizeof(knownMode.patch0);
207 		replacementCount++;
208 	}
209 	dprintf(DEVICE_NAME ": applied patch0 in %d locations\n", replacementCount);
210 
211 	replacementCount = 0;
212 	bios = biosBase;
213 	while (bios < biosEnd) {
214 		bios = (uint8_t*)memmem(bios, biosEnd - bios, knownMode.patch1, sizeof(knownMode.patch1));
215 		if (bios == NULL)
216 			break;
217 		memcpy(bios, allowedModes[i].patch1, sizeof(allowedModes[i].patch1));
218 		bios += sizeof(knownMode.patch1);
219 		replacementCount++;
220 	}
221 	dprintf(DEVICE_NAME ": applied patch1 in %d locations\n", replacementCount);
222 
223 	replacementCount = 0;
224 	bios = biosBase;
225 	while (bios < biosEnd) {
226 		bios = (uint8_t*)memmem(bios, biosEnd - bios, knownMode.patch2, sizeof(knownMode.patch2));
227 		if (bios == NULL)
228 			break;
229 		memcpy(bios, allowedModes[i].patch2, sizeof(allowedModes[i].patch2));
230 		bios += sizeof(knownMode.patch2);
231 		replacementCount++;
232 	}
233 	dprintf(DEVICE_NAME ": applied patch2 in %d locations\n", replacementCount);
234 
235 	replacementCount = 0;
236 	bios = biosBase;
237 	while (bios < biosEnd) {
238 		bios = (uint8_t*)memmem(bios, biosEnd - bios, knownMode.patch3, sizeof(knownMode.patch3));
239 		if (bios == NULL)
240 			break;
241 		memcpy(bios, allowedModes[i].patch3, sizeof(allowedModes[i].patch3));
242 		bios += sizeof(knownMode.patch3);
243 		replacementCount++;
244 	}
245 	dprintf(DEVICE_NAME ": applied patch3 in %d locations\n", replacementCount);
246 
247 	if ((biosBase[0x34] & 0x8F) == 0x80)
248 		biosBase[0x34] |= 0x01;
249 
250 	return B_OK;
251 }
252 
253 
254 status_t
255 vbe_patch_atom1_bios(vesa_info& info, bios_state* state, display_mode& mode)
256 {
257 	// Get a pointer to the BIOS
258 	const uintptr_t kBiosBase = 0xc0000;
259 	uint8_t* bios = (uint8_t*)sBIOSModule->virtual_address(state, kBiosBase);
260 
261 	ATOM_MODE_TIMING* timing = (ATOM_MODE_TIMING*)(bios + info.shared_info->mode_table_offset);
262 	dprintf(DEVICE_NAME ": patching ATOM mode timing (overwriting mode %dx%d)\n",
263 		timing->usCRTC_H_Disp, timing->usCRTC_V_Disp);
264 
265 	timing->usCRTC_H_Total = mode.timing.h_total;
266 	timing->usCRTC_H_Disp = mode.timing.h_display;
267 	timing->usCRTC_H_SyncStart = mode.timing.h_sync_start;
268 	timing->usCRTC_H_SyncWidth = mode.timing.h_sync_end - mode.timing.h_sync_start;
269 
270 	timing->usCRTC_V_Total = mode.timing.v_total;
271 	timing->usCRTC_V_Disp = mode.timing.v_display;
272 	timing->usCRTC_V_SyncStart = mode.timing.v_sync_start;
273 	timing->usCRTC_V_SyncWidth = mode.timing.v_sync_end - mode.timing.v_sync_start;
274 
275 	timing->usPixelClock = mode.timing.pixel_clock / 10;
276 
277 	return B_OK;
278 }
279 
280 
281 status_t
282 vbe_patch_atom2_bios(vesa_info& info, bios_state* state, display_mode& mode)
283 {
284 	// Get a pointer to the BIOS
285 	const uintptr_t kBiosBase = 0xc0000;
286 	uint8_t* bios = (uint8_t*)sBIOSModule->virtual_address(state, kBiosBase);
287 
288 	ATOM_DTD_FORMAT* timing = (ATOM_DTD_FORMAT*)(bios + info.shared_info->mode_table_offset);
289 	dprintf(DEVICE_NAME ": patching ATOM DTD format (overwriting mode %dx%d)\n",
290 		timing->usHActive, timing->usVActive);
291 
292 	timing->usHBlanking_Time = mode.timing.h_total - mode.timing.h_display;
293 	timing->usHActive = mode.timing.h_display;
294 	timing->usHSyncOffset = mode.timing.h_sync_start;
295 	timing->usHSyncWidth = mode.timing.h_sync_end - mode.timing.h_sync_start;
296 
297 	timing->usVBlanking_Time = mode.timing.v_total - mode.timing.v_display;
298 	timing->usVActive = mode.timing.v_display;
299 	timing->usVSyncOffset = mode.timing.v_sync_start;
300 	timing->usVSyncWidth = mode.timing.v_sync_end - mode.timing.v_sync_start;
301 
302 	timing->usPixClk = mode.timing.pixel_clock / 10;
303 
304 	return B_OK;
305 }
306 
307 
308 /*! Identify the BIOS type if it's one of the common ones, and locate where the BIOS store its
309  * allowed video modes table. We can then patch this table to add extra video modes that the
310  * manufacturer didn't allow.
311  */
312 void
313 vesa_identify_bios(bios_state* state, vesa_shared_info* sharedInfo)
314 {
315 	// Get a pointer to the BIOS
316 	const uintptr_t kBiosBase = 0xc0000;
317 	uint8_t* bios = (uint8_t*)sBIOSModule->virtual_address(state, kBiosBase);
318 
319 	const size_t kAtomBiosHeaderOffset = 0x48;
320 	const char kAtomSignature[] = {'A', 'T', 'O', 'M'};
321 
322 	ATOM_ROM_HEADER* atomRomHeader = (ATOM_ROM_HEADER*)(bios + kAtomBiosHeaderOffset);
323 
324 	sharedInfo->bios_type = kUnknownBiosType;
325 
326 	if (*(uint16*)(bios + 0x44) == 0x8086) {
327 		dprintf(DEVICE_NAME ": detected Intel BIOS\n");
328 
329 		// TODO check if we can find the mode table
330 		sharedInfo->bios_type = kIntelBiosType;
331 	} else if (memcmp(atomRomHeader->uaFirmWareSignature,  kAtomSignature, 4) == 0) {
332 		dprintf(DEVICE_NAME ": detected ATOM BIOS\n");
333 
334 		ATOM_MASTER_DATA_TABLE* masterDataTable = (ATOM_MASTER_DATA_TABLE*)(bios
335 			+ atomRomHeader->usMasterDataTableOffset);
336 		dprintf(DEVICE_NAME ": list of data tables: %p", &masterDataTable->ListOfDataTables);
337 		ATOM_ANALOG_TV_INFO* standardVesaTable = (ATOM_ANALOG_TV_INFO*)(bios
338 			+ masterDataTable->ListOfDataTables.StandardVESA_Timing);
339 		dprintf(DEVICE_NAME ": std_vesa: %p", standardVesaTable);
340 		sharedInfo->mode_table_offset = (uint8*)&standardVesaTable->aModeTimings - bios;
341 
342 		size_t tableSize = standardVesaTable->sHeader.usStructureSize
343 			- sizeof(ATOM_COMMON_TABLE_HEADER);
344 		if (tableSize % sizeof(ATOM_MODE_TIMING) == 0)
345 			sharedInfo->bios_type = kAtomBiosType2;
346 		else
347 			sharedInfo->bios_type = kAtomBiosType1;
348 	} else if (memmem(bios, 512, "NVID", 4) != NULL) {
349 		dprintf(DEVICE_NAME ": detected nVidia BIOS\n");
350 
351 		// TODO check if we can find the mode table
352 		sharedInfo->bios_type = kNVidiaBiosType;
353 	} else {
354 		dprintf(DEVICE_NAME ": unknown BIOS type, custom video modes will not be available\n");
355 	}
356 }
357 
358 
359 /*! Set a custom display mode by live patching the VESA BIOS to insert it in the modeline table.
360  *
361  * This is only supported for some video cards, where the format of the mode lines is known.
362  */
363 status_t
364 vesa_set_custom_display_mode(vesa_info& info, display_mode& mode)
365 {
366 	int32 modeIndex = -1;
367 	if (info.shared_info->bios_type == kUnknownBiosType)
368 		return B_NOT_SUPPORTED;
369 
370 	// Prepare BIOS environment
371 	bios_state* state;
372 	status_t status = vbe_call_prepare(&state);
373 	if (status != B_OK)
374 		return status;
375 
376 	// Patch bios to inject custom video mode
377 	switch (info.shared_info->bios_type) {
378 		case kIntelBiosType:
379 			status = vbe_patch_intel_bios(state, mode);
380 			// The patch replaces the 1024x768 modes with our custom resolution. We can then use
381 			// mode 0x118 which is the standard VBE2 mode for 1024x768 at 32 bits per pixel, and
382 			// know it will use our new timings.
383 			break;
384 		case kNVidiaBiosType:
385 			status = vbe_patch_nvidia_bios(state, mode);
386 			break;
387 		case kAtomBiosType1:
388 			status = vbe_patch_atom1_bios(info, state, mode);
389 			break;
390 		case kAtomBiosType2:
391 			status = vbe_patch_atom2_bios(info, state, mode);
392 			break;
393 		default:
394 			status = B_NOT_SUPPORTED;
395 			break;
396 	}
397 
398 	if (status != B_OK)
399 		goto out;
400 
401 	// The patching modified some mode, but we don't know which one. So we need to rescan the mode
402 	// list to find the correct one.
403 	struct vbe_mode_info modeInfo;
404 	for (uint32 i = 0; i < info.shared_info->vesa_mode_count; i++) {
405 		status = vbe_get_mode_info(state, info.modes[i].mode, &modeInfo);
406 		if (status != B_OK) {
407 			// Sometimes the patching prevents us from getting the mode info?
408 			dprintf(DEVICE_NAME ": vesa_set_custom_display_mode(): cannot get mode info for %x\n",
409 				info.modes[i].mode);
410 			// Just ignore modes that turn out to be invalid...
411 			continue;
412 		}
413 
414 		if (modeInfo.width == mode.timing.h_display && modeInfo.height == mode.timing.v_display
415 			&& get_color_space_for_depth(info.modes[i].bits_per_pixel) == mode.space) {
416 			modeIndex = info.modes[i].mode;
417 			break;
418 		}
419 	}
420 
421 	if (modeIndex >= 0) {
422 		dprintf(DEVICE_NAME ": custom mode resolution %dx%d succesfully patched at index %"
423 			B_PRIx32 "\n", modeInfo.width, modeInfo.height, modeIndex);
424 	} else {
425 		dprintf(DEVICE_NAME ": video mode patching failed!\n");
426 		goto out;
427 	}
428 
429 	// Set mode
430 	status = vbe_set_mode(state, modeIndex);
431 	if (status != B_OK) {
432 		dprintf(DEVICE_NAME ": vesa_set_custom_display_mode(): cannot set mode\n");
433 		goto out;
434 	}
435 
436 	if (info.modes[modeIndex].bits_per_pixel <= 8)
437 		vbe_set_bits_per_gun(state, info, 8);
438 
439 	// Map new frame buffer if necessary
440 
441 	status = remap_frame_buffer(info, modeInfo.physical_base, modeInfo.width,
442 		modeInfo.height, modeInfo.bits_per_pixel, modeInfo.bytes_per_row,
443 		false);
444 
445 	if (status == B_OK) {
446 		// Update shared frame buffer information
447 		info.shared_info->current_mode.virtual_width = modeInfo.width;
448 		info.shared_info->current_mode.virtual_height = modeInfo.height;
449 		info.shared_info->current_mode.space = get_color_space_for_depth(
450 			modeInfo.bits_per_pixel);
451 	}
452 
453 out:
454 	vbe_call_finish(state);
455 	return status;
456 }
457 
458 
459