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1/*␊
2 * Copyright (c) 1999-2003 Apple Computer, Inc. All rights reserved.␊
3 *␊
4 * @APPLE_LICENSE_HEADER_START@␊
5 * ␊
6 * Portions Copyright (c) 1999-2003 Apple Computer, Inc. All Rights␊
7 * Reserved. This file contains Original Code and/or Modifications of␊
8 * Original Code as defined in and that are subject to the Apple Public␊
9 * Source License Version 2.0 (the "License"). You may not use this file␊
10 * except in compliance with the License. Please obtain a copy of the␊
11 * License at http://www.apple.com/publicsource and read it before using␊
12 * this file.␊
13 * ␊
14 * The Original Code and all software distributed under the License are␊
15 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER␊
16 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,␊
17 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,␊
18 * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT. Please see the␊
19 * License for the specific language governing rights and limitations␊
20 * under the License.␊
21 * ␊
22 * @APPLE_LICENSE_HEADER_END@␊
23 */␊
24/*␊
25 * Copyright 1993 NeXT, Inc.␊
26 * All rights reserved.␊
27 */␊
28␊
29#include "libsaio.h"␊
30#include "vbe.h"␊
31␊
32/*␊
33 * Globals␊
34 */␊
35static biosBuf_t bb;␊
36␊
37int getVBEInfo( void * infoBlock )␊
38{␊
39 bb.intno = 0x10;␊
40 bb.eax.rr = funcGetControllerInfo;␊
41 bb.es = SEG( infoBlock );␊
42 bb.edi.rr = OFF( infoBlock );␊
43 bios( &bb );␊
44 return(bb.eax.r.h);␊
45}␊
46␊
47int getVBEModeInfo( int mode, void * minfo_p )␊
48{␊
49 bb.intno = 0x10;␊
50 bb.eax.rr = funcGetModeInfo;␊
51 bb.ecx.rr = mode;␊
52 bb.es = SEG(minfo_p);␊
53 bb.edi.rr = OFF(minfo_p);␊
54 bios(&bb);␊
55 return(bb.eax.r.h);␊
56}␊
57#if UNUSED␊
58int getVBEDACFormat(unsigned char *format)␊
59{␊
60 bb.intno = 0x10;␊
61 bb.eax.rr = funcGetSetPaletteFormat;␊
62 bb.ebx.r.l = subfuncGet;␊
63 bios(&bb);␊
64 *format = bb.ebx.r.h;␊
65 return(bb.eax.r.h);␊
66}␊
67␊
68int setVBEDACFormat(unsigned char format)␊
69{␊
70 bb.intno = 0x10;␊
71 bb.eax.rr = funcGetSetPaletteFormat;␊
72 bb.ebx.r.l = subfuncSet;␊
73 bb.ebx.r.h = format;␊
74 bios(&bb);␊
75 return(bb.eax.r.h);␊
76}␊
77#endif␊
78␊
79#if UNUSED␊
80␊
81int getEDID( void * edidBlock, UInt8 block)␊
82{␊
83␉bzero(&bb, sizeof(biosBuf_t));␊
84 bb.intno = 0x10;␊
85 bb.eax.rr = funcGetEDID;␊
86␉bb.ebx.r.l= 0x01;␊
87␉bb.edx.rr = block;␊
88␉␊
89 bb.es = SEG( edidBlock );␊
90 bb.edi.rr = OFF( edidBlock );␊
91␉␊
92 bios( &bb );␊
93 return(bb.eax.r.h);␊
94}␊
95␊
96␊
97␊
98/*␊
99 * Default GTF parameter values.␊
100 */␊
101#define kCellGranularity 8.0 // character cell granularity␊
102#define kMinVSyncPlusBP 550.0 // min VSync + BP interval (us)␊
103#define kMinFrontPorch 1.0 // minimum front porch in lines(V)/cells(H)␊
104#define kVSyncLines 3.0 // width of VSync in lines␊
105#define kHSyncWidth 8.0 // HSync as a percent of total line width␊
106#define kC 30.0 // C = (C'-J) * (K/256) + J␊
107#define kM 300.0 // M = K/256 * M'␊
108␊
109static int Round(double f)␊
110{␊
111␉return (int)(f + 0.5);␊
112}␊
113␊
114/*␊
115 * from http://www.azillionmonkeys.com/qed/sqroot.html␊
116 */␊
117double Sqrt( double y )␊
118{␊
119␉double x, z, tempf;␊
120␉unsigned long *tfptr = ((unsigned long *)&tempf) + 1;␊
121␉␊
122␉tempf = y;␊
123␉*tfptr = (0xbfcdd90a - *tfptr)>>1; /* estimate of 1/sqrt(y) */␊
124␉x = tempf;␊
125␉z = y*0.5; /* hoist out the “/2” */␊
126␉x = (1.5*x) - (x*x)*(x*z); /* iteration formula */␊
127␉x = (1.5*x) - (x*x)*(x*z);␊
128␉x = (1.5*x) - (x*x)*(x*z);␊
129␉x = (1.5*x) - (x*x)*(x*z);␊
130␉x = (1.5*x) - (x*x)*(x*z);␊
131␉return x*y;␊
132}␊
133␊
134int generateCRTCTiming( unsigned short width,␊
135 unsigned short height,␊
136 unsigned long paramValue, ␊
137 int paramType,␊
138 VBECRTCInfoBlock * timing )␊
139{␊
140 double h_period_est, h_freq, h_period, h_total_pixels, h_sync_pixels;␊
141 double h_active_pixels, h_ideal_duty_cycle, h_blank_pixels, pixel_freq = 0;␊
142 double v_sync_plus_bp = 0, v_total_lines = 0, v_field_rate_est, v_frame_rate = 0;␊
143 const double h_pixels = (double) width;␊
144 const double v_lines = (double) height;␊
145␊
146 enum {␊
147 left_margin_pixels = 0,␊
148 right_margin_pixels = 0,␊
149 top_margin_lines = 0,␊
150 bot_margin_lines = 0,␊
151 interlace = 0␊
152 };␊
153␊
154 // Total number of active pixels in image and both margins␊
155 h_active_pixels = h_pixels + left_margin_pixels + right_margin_pixels;␊
156␊
157 if (paramType == kCRTCParamPixelClock)␊
158 {␊
159 // Pixel clock provided in MHz␊
160 pixel_freq = (double) paramValue / 1000000;␊
161␊
162 // Ideal horizontal period from the blanking duty cycle equation␊
163 h_period = ((kC - 100) + (Sqrt(((100 - kC) * (100 - kC)) + (0.4 * kM *␊
164 (h_active_pixels + right_margin_pixels + left_margin_pixels) /␊
165 pixel_freq)))) / 2.0 / kM * 1000;␊
166 }␊
167 else /* kCRTCParamRefreshRate */␊
168 {␊
169 double v_field_rate_in = (double) paramValue;␊
170␊
171 // Estimate the horizontal period␊
172 h_period_est = ((1 / v_field_rate_in) - kMinVSyncPlusBP / 1000000) /␊
173 (v_lines + (2 * top_margin_lines) + kMinFrontPorch + interlace) * ␊
174 1000000;␊
175␊
176 // Number of lines in Vsync + back porch␊
177 v_sync_plus_bp = Round(kMinVSyncPlusBP / h_period_est);␊
178␊
179 // Total number of lines in Vetical field period␊
180 v_total_lines = v_lines + top_margin_lines + bot_margin_lines +␊
181 v_sync_plus_bp + interlace + kMinFrontPorch;␊
182␊
183 // Estimate the vertical field frequency␊
184 v_field_rate_est = 1 / h_period_est / v_total_lines * 1000000;␊
185␊
186 // Find the actual horizontal period␊
187 h_period = h_period_est / (v_field_rate_in / v_field_rate_est);␊
188␊
189 // Find the vertical frame rate (no interlace)␊
190 v_frame_rate = 1 / h_period / v_total_lines * 1000000;␊
191 }␊
192␊
193 // Ideal blanking duty cycle from the blanking duty cycle equation␊
194 h_ideal_duty_cycle = kC - (kM * h_period / 1000);␊
195␊
196 // Number of pixels in the blanking time to the nearest double character cell␊
197 h_blank_pixels = Round(h_active_pixels * h_ideal_duty_cycle /␊
198 (100 - h_ideal_duty_cycle) / (2 * kCellGranularity)) *␊
199 (2 * kCellGranularity);␊
200␊
201 // Total number of horizontal pixels␊
202 h_total_pixels = h_active_pixels + h_blank_pixels;␊
203␊
204 if (paramType == kCRTCParamPixelClock)␊
205 {␊
206 // Horizontal frequency␊
207 h_freq = pixel_freq / h_total_pixels * 1000;␊
208␊
209 // Number of lines in V sync + back porch␊
210 v_sync_plus_bp = Round(kMinVSyncPlusBP * h_freq / 1000);␊
211␊
212 // Total number of lines in vertical field period␊
213 v_total_lines = v_lines + top_margin_lines + bot_margin_lines +␊
214 interlace + v_sync_plus_bp + kMinFrontPorch;␊
215␊
216 // Vertical frame frequency␊
217 v_frame_rate = Round(h_freq / v_total_lines * 1000);␊
218 }␊
219 else␊
220 {␊
221 // Find pixel clock frequency␊
222 pixel_freq = Round(h_total_pixels / h_period);␊
223 }␊
224␊
225 h_sync_pixels = Round(h_total_pixels * kHSyncWidth / 100 / kCellGranularity) *␊
226 kCellGranularity;␊
227␊
228 timing->HTotal = h_total_pixels;␊
229 timing->HSyncStart = h_active_pixels + (h_blank_pixels / 2) - h_sync_pixels;␊
230 timing->HSyncEnd = timing->HSyncStart + h_sync_pixels;␊
231 timing->VTotal = v_total_lines;␊
232 timing->VSyncStart = v_total_lines - v_sync_plus_bp;␊
233 timing->VSyncEnd = timing->VSyncStart + kVSyncLines;␊
234 timing->Flags = kCRTCNegativeHorizontalSync;␊
235 timing->PixelClock = pixel_freq * 1000000;␊
236 timing->RefreshRate = v_frame_rate * 100;␊
237␊
238 return 0;␊
239}␊
240␊
241#endif ␊
242␊
243int setVBEMode(unsigned short mode, const VBECRTCInfoBlock * timing)␊
244{␊
245 bb.intno = 0x10;␊
246 bb.eax.rr = funcSetMode;␊
247 bb.ebx.rr = mode;␊
248 if (timing) {␊
249 bb.es = SEG(timing);␊
250 bb.edi.rr = OFF(timing);␊
251 }␊
252 bios(&bb);␊
253 return(bb.eax.r.h);␊
254}␊
255␊
256␊
257int setVBEPalette(void *palette)␊
258{␊
259 bb.intno = 0x10;␊
260 bb.eax.rr = funcGetSetPaletteData;␊
261 bb.ebx.r.l = subfuncSet;␊
262 bb.ecx.rr = 256;␊
263 bb.edx.rr = 0;␊
264 bb.es = SEG(palette);␊
265 bb.edi.rr = OFF(palette);␊
266 bios(&bb);␊
267 return(bb.eax.r.h);␊
268}␊
269␊
270#if UNUSED␊
271␊
272int getVBEPalette(void *palette)␊
273{␊
274 bb.intno = 0x10;␊
275 bb.eax.rr = funcGetSetPaletteData;␊
276 bb.ebx.r.l = subfuncGet;␊
277 bb.ecx.rr = 256;␊
278 bb.edx.rr = 0;␊
279 bb.es = SEG(palette);␊
280 bb.edi.rr = OFF(palette);␊
281 bios(&bb);␊
282 return(bb.eax.r.h);␊
283}␊
284␊
285int getVBECurrentMode(unsigned short *mode)␊
286{␊
287 bb.intno = 0x10;␊
288 bb.eax.rr = funcGetCurrentMode;␊
289 bios(&bb);␊
290 *mode = bb.ebx.rr;␊
291 return(bb.eax.r.h);␊
292}␊
293␊
294int getVBEPixelClock(unsigned short mode, unsigned long * pixelClock)␊
295{␊
296 bb.intno = 0x10;␊
297 bb.eax.rr = funcGetSetPixelClock;␊
298 bb.ebx.r.l = 0;␊
299 bb.ecx.rx = *pixelClock;␊
300 bb.edx.rr = mode;␊
301 bios(&bb);␊
302 *pixelClock = bb.ecx.rx;␊
303 return(bb.eax.r.h);␊
304}␊
305#endif␊
306

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