*
* @APPLE_LICENSE_HEADER_START@
*
- * Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
- * Reserved. This file contains Original Code and/or Modifications of
- * Original Code as defined in and that are subject to the Apple Public
- * Source License Version 1.1 (the "License"). You may not use this file
- * except in compliance with the License. Please obtain a copy of the
- * License at http://www.apple.com/publicsource and read it before using
- * this file.
+ * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
*
* The Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
return(bb.eax.r.h);
}
-int setVBEMode(unsigned short mode)
+/*
+ * Default GTF parameter values.
+ */
+#define kCellGranularity 8.0 // character cell granularity
+#define kMinVSyncPlusBP 550.0 // min VSync + BP interval (us)
+#define kMinFrontPorch 1.0 // minimum front porch in lines(V)/cells(H)
+#define kVSyncLines 3.0 // width of VSync in lines
+#define kHSyncWidth 8.0 // HSync as a percent of total line width
+#define kC 30.0 // C = (C'-J) * (K/256) + J
+#define kM 300.0 // M = K/256 * M'
+
+static inline double Round( double f )
{
- bb.intno = 0x10;
+ asm volatile ("frndint" : "=t" (f) : "0" (f));
+ return f;
+}
+
+static inline double Sqrt( double f )
+{
+ asm volatile ("fsqrt" : "=t" (f) : "0" (f));
+ return f;
+}
+
+int generateCRTCTiming( unsigned short width,
+ unsigned short height,
+ unsigned long paramValue,
+ int paramType,
+ VBECRTCInfoBlock * timing )
+{
+ double h_period_est, h_freq, h_period, h_total_pixels, h_sync_pixels;
+ double h_active_pixels, h_ideal_duty_cycle, h_blank_pixels, pixel_freq = 0;
+ double v_sync_plus_bp = 0, v_total_lines = 0, v_field_rate_est, v_frame_rate = 0;
+ const double h_pixels = (double) width;
+ const double v_lines = (double) height;
+
+ enum {
+ left_margin_pixels = 0,
+ right_margin_pixels = 0,
+ top_margin_lines = 0,
+ bot_margin_lines = 0,
+ interlace = 0
+ };
+
+ // Total number of active pixels in image and both margins
+ h_active_pixels = h_pixels + left_margin_pixels + right_margin_pixels;
+
+ if (paramType == kCRTCParamPixelClock)
+ {
+ // Pixel clock provided in MHz
+ pixel_freq = (double) paramValue / 1000000;
+
+ // Ideal horizontal period from the blanking duty cycle equation
+ h_period = ((kC - 100) + (Sqrt(((100 - kC) * (100 - kC)) + (0.4 * kM *
+ (h_active_pixels + right_margin_pixels + left_margin_pixels) /
+ pixel_freq)))) / 2.0 / kM * 1000;
+ }
+ else /* kCRTCParamRefreshRate */
+ {
+ double v_field_rate_in = (double) paramValue;
+
+ // Estimate the horizontal period
+ h_period_est = ((1 / v_field_rate_in) - kMinVSyncPlusBP / 1000000) /
+ (v_lines + (2 * top_margin_lines) + kMinFrontPorch + interlace) *
+ 1000000;
+
+ // Number of lines in Vsync + back porch
+ v_sync_plus_bp = Round(kMinVSyncPlusBP / h_period_est);
+
+ // Total number of lines in Vetical field period
+ v_total_lines = v_lines + top_margin_lines + bot_margin_lines +
+ v_sync_plus_bp + interlace + kMinFrontPorch;
+
+ // Estimate the vertical field frequency
+ v_field_rate_est = 1 / h_period_est / v_total_lines * 1000000;
+
+ // Find the actual horizontal period
+ h_period = h_period_est / (v_field_rate_in / v_field_rate_est);
+
+ // Find the vertical frame rate (no interlace)
+ v_frame_rate = 1 / h_period / v_total_lines * 1000000;
+ }
+
+ // Ideal blanking duty cycle from the blanking duty cycle equation
+ h_ideal_duty_cycle = kC - (kM * h_period / 1000);
+
+ // Number of pixels in the blanking time to the nearest double character cell
+ h_blank_pixels = Round(h_active_pixels * h_ideal_duty_cycle /
+ (100 - h_ideal_duty_cycle) / (2 * kCellGranularity)) *
+ (2 * kCellGranularity);
+
+ // Total number of horizontal pixels
+ h_total_pixels = h_active_pixels + h_blank_pixels;
+
+ if (paramType == kCRTCParamPixelClock)
+ {
+ // Horizontal frequency
+ h_freq = pixel_freq / h_total_pixels * 1000;
+
+ // Number of lines in V sync + back porch
+ v_sync_plus_bp = Round(kMinVSyncPlusBP * h_freq / 1000);
+
+ // Total number of lines in vertical field period
+ v_total_lines = v_lines + top_margin_lines + bot_margin_lines +
+ interlace + v_sync_plus_bp + kMinFrontPorch;
+
+ // Vertical frame frequency
+ v_frame_rate = Round(h_freq / v_total_lines * 1000);
+ }
+ else
+ {
+ // Find pixel clock frequency
+ pixel_freq = Round(h_total_pixels / h_period);
+ }
+
+ h_sync_pixels = Round(h_total_pixels * kHSyncWidth / 100 / kCellGranularity) *
+ kCellGranularity;
+
+ timing->HTotal = h_total_pixels;
+ timing->HSyncStart = h_active_pixels + (h_blank_pixels / 2) - h_sync_pixels;
+ timing->HSyncEnd = timing->HSyncStart + h_sync_pixels;
+ timing->VTotal = v_total_lines;
+ timing->VSyncStart = v_total_lines - v_sync_plus_bp;
+ timing->VSyncEnd = timing->VSyncStart + kVSyncLines;
+ timing->Flags = kCRTCNegativeHorizontalSync;
+ timing->PixelClock = pixel_freq * 1000000;
+ timing->RefreshRate = v_frame_rate * 100;
+
+ return 0;
+}
+
+int setVBEMode(unsigned short mode, const VBECRTCInfoBlock * timing)
+{
+ bb.intno = 0x10;
bb.eax.rr = funcSetMode;
bb.ebx.rr = mode;
+ if (timing) {
+ bb.es = SEG(timing);
+ bb.edi.rr = OFF(timing);
+ }
bios(&bb);
return(bb.eax.r.h);
}
*mode = bb.ebx.rr;
return(bb.eax.r.h);
}
+
+int getVBEPixelClock(unsigned short mode, unsigned long * pixelClock)
+{
+ bb.intno = 0x10;
+ bb.eax.rr = funcGetSetPixelClock;
+ bb.ebx.r.l = 0;
+ bb.ecx.rx = *pixelClock;
+ bb.edx.rr = mode;
+ bios(&bb);
+ *pixelClock = bb.ecx.rx;
+ return(bb.eax.r.h);
+}
projects / apple / boot.git / blobdiff