src/Unix/video_vosf.h

/*
 *  video_vosf.h - Video/graphics emulation, video on SEGV signals support
 *
 *  Basilisk II (C) 1997-2001 Christian Bauer
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef VIDEO_VOSF_H
#define VIDEO_VOSF_H

// Note: this file is #include'd in video_x.cpp
#ifdef ENABLE_VOSF

/*
 *  Page-aligned memory allocation
 */

// Extend size to page boundary
static uint32 page_extend(uint32 size)
{
        const uint32 page_size = getpagesize();
        const uint32 page_mask = page_size - 1;
        return (size + page_mask) & ~page_mask;
}

// Screen fault handler
static bool screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction)
{
        D(bug("screen_fault_handler: ADDR=0x%08X from IP=0x%08X\n", fault_address, fault_instruction));
        const uintptr addr = (uintptr)fault_address;
        
        /* Someone attempted to write to the frame buffer. Make it writeable
         * now so that the data could actually be written. It will be made
         * read-only back in one of the screen update_*() functions.
         */
        if ((addr >= mainBuffer.memStart) && (addr < mainBuffer.memEnd)) {
                const int page  = (addr - mainBuffer.memStart) >> mainBuffer.pageBits;
                caddr_t page_ad = (caddr_t)(addr & -mainBuffer.pageSize);
                LOCK_VOSF;
                PFLAG_SET(page);
                vm_protect((char *)page_ad, mainBuffer.pageSize, VM_PAGE_READ | VM_PAGE_WRITE);
                mainBuffer.dirty = true;
                UNLOCK_VOSF;
                return true;
        }
        
        /* Otherwise, we don't know how to handle the fault, let it crash */
        fprintf(stderr, "do_handle_screen_fault: unhandled address 0x%08X", addr);
        if (fault_instruction != SIGSEGV_INVALID_PC)
                fprintf(stderr, " [IP=0x%08X]", fault_instruction);
        fprintf(stderr, "\n");
        return false;
}

/*
 *      Update display for Windowed mode and VOSF
 */

// From video_blit.cpp
extern void (*Screen_blit)(uint8 * dest, const uint8 * source, uint32 length);
extern bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order);

/*      How can we deal with array overrun conditions ?
        
        The state of the framebuffer pages that have been touched are maintained
        in the dirtyPages[] table. That table is (pageCount + 2) bytes long.

Terminology
        
        "Last Page" denotes the pageCount-nth page, i.e. dirtyPages[pageCount - 1].
        "CLEAR Page Guard" refers to the page following the Last Page but is always
        in the CLEAR state. "SET Page Guard" refers to the page following the CLEAR
        Page Guard but is always in the SET state.

Rough process
        
        The update routines must determine which pages have to be blitted to the
        screen. This job consists in finding the first_page that was touched.
        i.e. find the next page that is SET. Then, finding how many pages were
        touched starting from first_page. i.e. find the next page that is CLEAR.

There are two cases to check:

        - Last Page is CLEAR: find_next_page_set() will reach the SET Page Guard
        but it is beyond the valid pageCount value. Therefore, we exit from the
        update routine.
        
        - Last Page is SET: first_page equals (pageCount - 1) and
        find_next_page_clear() will reach the CLEAR Page Guard. We blit the last
        page to the screen. On the next iteration, page equals pageCount and
        find_next_page_set() will reach the SET Page Guard. We still safely exit
        from the update routine because the SET Page Guard position is greater
        than pageCount.
*/

static inline void update_display_window_vosf(void)
{
        int page = 0;
        for (;;) {
                const int first_page = find_next_page_set(page);
                if (first_page >= mainBuffer.pageCount)
                        break;

                page = find_next_page_clear(first_page);
                PFLAG_CLEAR_RANGE(first_page, page);

                // Make the dirty pages read-only again
                const int32 offset  = first_page << mainBuffer.pageBits;
                const uint32 length = (page - first_page) << mainBuffer.pageBits;
                vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
                
                // There is at least one line to update
                const int y1 = mainBuffer.pageInfo[first_page].top;
                const int y2 = mainBuffer.pageInfo[page - 1].bottom;
                const int height = y2 - y1 + 1;
                
                const int bytes_per_row = VideoMonitor.bytes_per_row;
                const int bytes_per_pixel = VideoMonitor.bytes_per_row / VideoMonitor.x;
                int i = y1 * bytes_per_row, j;
                
                if (depth == 1) {

                        // Update the_host_buffer and copy of the_buffer
                        for (j = y1; j <= y2; j++) {
                                Screen_blit(the_host_buffer + i, the_buffer + i, VideoMonitor.x >> 3);
                                i += bytes_per_row;
                        }

                } else {

                        // Update the_host_buffer and copy of the_buffer
                        for (j = y1; j <= y2; j++) {
                                Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * VideoMonitor.x);
                                i += bytes_per_row;
                        }
                }

                if (have_shm)
                        XShmPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.x, height, 0);
                else
                        XPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.x, height);
        }

        mainBuffer.dirty = false;
}


/*
 *      Update display for DGA mode and VOSF
 *      (only in Direct Addressing mode)
 */

#if REAL_ADDRESSING || DIRECT_ADDRESSING
static inline void update_display_dga_vosf(void)
{
        int page = 0;
        for (;;) {
                const int first_page = find_next_page_set(page);
                if (first_page >= mainBuffer.pageCount)
                        break;

                page = find_next_page_clear(first_page);
                PFLAG_CLEAR_RANGE(first_page, page);

                // Make the dirty pages read-only again
                const int32 offset  = first_page << mainBuffer.pageBits;
                const uint32 length = (page - first_page) << mainBuffer.pageBits;
                vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
                
                // I am sure that y2 >= y1 and depth != 1
                const int y1 = mainBuffer.pageInfo[first_page].top;
                const int y2 = mainBuffer.pageInfo[page - 1].bottom;
                
                const int bytes_per_row = VideoMonitor.bytes_per_row;
                const int bytes_per_pixel = VideoMonitor.bytes_per_row / VideoMonitor.x;
                int i, j;
                
                // Check for first column from left and first column
                // from right that have changed
                int x1 = VideoMonitor.x * bytes_per_pixel - 1;
                for (j = y1; j <= y2; j++) {
                        uint8 * const p1 = &the_buffer[j * bytes_per_row];
                        uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
                        for (i = 0; i < x1; i++) {
                                if (p1[i] != p2[i]) {
                                        x1 = i;
                                        break;
                                }
                        }
                }
                x1 /= bytes_per_pixel;
                
                int x2 = x1 * bytes_per_pixel;
                for (j = y2; j >= y1; j--) {
                        uint8 * const p1 = &the_buffer[j * bytes_per_row];
                        uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
                        for (i = VideoMonitor.x * bytes_per_pixel - 1; i > x2; i--) {
                                if (p1[i] != p2[i]) {
                                        x2 = i;
                                        break;
                                }
                        }
                }
                x2 /= bytes_per_pixel;
                
                // Update the_host_buffer and copy of the_buffer
                // There should be at least one pixel to copy
                const int width = x2 - x1 + 1;
                i = y1 * bytes_per_row + x1 * bytes_per_pixel;
                for (j = y1; j <= y2; j++) {
                        Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width);
                        memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width);
                        i += bytes_per_row;
                }
        }
        mainBuffer.dirty = false;
}
#endif

#endif /* ENABLE_VOSF */

#endif /* VIDEO_VOSF_H */
Revision:	1.17
Committed:	2001-06-26T22:35:41Z (23 years, 4 months ago) by gbeauche
Content type:	text/plain
Branch:	MAIN
Changes since 1.16:	+6 -13 lines
Log Message:	- added SIGSEGV support for Linux/Alpha (to be checked), Darwin/PPC - added uniform virtual memory allocation (supports mmap(), vm_allocate(), or fallbacks to malloc()/free()) - cleaned up memory allocation in main_unix.cpp
#	User	Rev	Content
1	gbeauche	1.1	/*
2			* video_vosf.h - Video/graphics emulation, video on SEGV signals support
3			*
4	gbeauche	1.13	* Basilisk II (C) 1997-2001 Christian Bauer
5	gbeauche	1.1	*
6			* This program is free software; you can redistribute it and/or modify
7			* it under the terms of the GNU General Public License as published by
8			* the Free Software Foundation; either version 2 of the License, or
9			* (at your option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the GNU General Public License
17			* along with this program; if not, write to the Free Software
18			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19			*/
20
21			#ifndef VIDEO_VOSF_H
22			#define VIDEO_VOSF_H
23
24			// Note: this file is #include'd in video_x.cpp
25			#ifdef ENABLE_VOSF
26
27			/*
28			* Page-aligned memory allocation
29			*/
30
31	gbeauche	1.17	// Extend size to page boundary
32			static uint32 page_extend(uint32 size)
33	gbeauche	1.1	{
34			const uint32 page_size = getpagesize();
35			const uint32 page_mask = page_size - 1;
36			return (size + page_mask) & ~page_mask;
37			}
38
39	gbeauche	1.16	// Screen fault handler
40			static bool screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction)
41	gbeauche	1.1	{
42	gbeauche	1.16	D(bug("screen_fault_handler: ADDR=0x%08X from IP=0x%08X\n", fault_address, fault_instruction));
43			const uintptr addr = (uintptr)fault_address;
44
45	gbeauche	1.11	/* Someone attempted to write to the frame buffer. Make it writeable
46			* now so that the data could actually be written. It will be made
47			* read-only back in one of the screen update_*() functions.
48			*/
49			if ((addr >= mainBuffer.memStart) && (addr < mainBuffer.memEnd)) {
50			const int page = (addr - mainBuffer.memStart) >> mainBuffer.pageBits;
51	gbeauche	1.17	caddr_t page_ad = (caddr_t)(addr & -mainBuffer.pageSize);
52	gbeauche	1.11	LOCK_VOSF;
53			PFLAG_SET(page);
54	gbeauche	1.17	vm_protect((char *)page_ad, mainBuffer.pageSize, VM_PAGE_READ \| VM_PAGE_WRITE);
55	gbeauche	1.13	mainBuffer.dirty = true;
56	gbeauche	1.11	UNLOCK_VOSF;
57	gbeauche	1.16	return true;
58	gbeauche	1.1	}
59
60	gbeauche	1.11	/* Otherwise, we don't know how to handle the fault, let it crash */
61			fprintf(stderr, "do_handle_screen_fault: unhandled address 0x%08X", addr);
62	gbeauche	1.16	if (fault_instruction != SIGSEGV_INVALID_PC)
63			fprintf(stderr, " [IP=0x%08X]", fault_instruction);
64	gbeauche	1.11	fprintf(stderr, "\n");
65	gbeauche	1.16	return false;
66	gbeauche	1.1	}
67
68			/*
69			* Update display for Windowed mode and VOSF
70			*/
71
72	gbeauche	1.13	// From video_blit.cpp
73			extern void (Screen_blit)(uint8 dest, const uint8 * source, uint32 length);
74			extern bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order);
75
76	gbeauche	1.12	/* How can we deal with array overrun conditions ?
77
78			The state of the framebuffer pages that have been touched are maintained
79			in the dirtyPages[] table. That table is (pageCount + 2) bytes long.
80
81			Terminology
82
83			"Last Page" denotes the pageCount-nth page, i.e. dirtyPages[pageCount - 1].
84			"CLEAR Page Guard" refers to the page following the Last Page but is always
85			in the CLEAR state. "SET Page Guard" refers to the page following the CLEAR
86			Page Guard but is always in the SET state.
87
88			Rough process
89
90	gbeauche	1.13	The update routines must determine which pages have to be blitted to the
91	gbeauche	1.12	screen. This job consists in finding the first_page that was touched.
92			i.e. find the next page that is SET. Then, finding how many pages were
93			touched starting from first_page. i.e. find the next page that is CLEAR.
94
95	gbeauche	1.13	There are two cases to check:
96	gbeauche	1.12
97			- Last Page is CLEAR: find_next_page_set() will reach the SET Page Guard
98			but it is beyond the valid pageCount value. Therefore, we exit from the
99			update routine.
100
101			- Last Page is SET: first_page equals (pageCount - 1) and
102			find_next_page_clear() will reach the CLEAR Page Guard. We blit the last
103			page to the screen. On the next iteration, page equals pageCount and
104			find_next_page_set() will reach the SET Page Guard. We still safely exit
105			from the update routine because the SET Page Guard position is greater
106			than pageCount.
107			*/
108
109	gbeauche	1.1	static inline void update_display_window_vosf(void)
110			{
111			int page = 0;
112			for (;;) {
113	gbeauche	1.11	const int first_page = find_next_page_set(page);
114			if (first_page >= mainBuffer.pageCount)
115	gbeauche	1.1	break;
116	gbeauche	1.11
117			page = find_next_page_clear(first_page);
118			PFLAG_CLEAR_RANGE(first_page, page);
119	cebix	1.7
120	gbeauche	1.1	// Make the dirty pages read-only again
121			const int32 offset = first_page << mainBuffer.pageBits;
122			const uint32 length = (page - first_page) << mainBuffer.pageBits;
123	gbeauche	1.17	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
124	gbeauche	1.1
125			// There is at least one line to update
126			const int y1 = mainBuffer.pageInfo[first_page].top;
127			const int y2 = mainBuffer.pageInfo[page - 1].bottom;
128			const int height = y2 - y1 + 1;
129
130			const int bytes_per_row = VideoMonitor.bytes_per_row;
131			const int bytes_per_pixel = VideoMonitor.bytes_per_row / VideoMonitor.x;
132	cebix	1.15	int i = y1 * bytes_per_row, j;
133	gbeauche	1.1
134	cebix	1.6	if (depth == 1) {
135
136			// Update the_host_buffer and copy of the_buffer
137			for (j = y1; j <= y2; j++) {
138	cebix	1.15	Screen_blit(the_host_buffer + i, the_buffer + i, VideoMonitor.x >> 3);
139	cebix	1.6	i += bytes_per_row;
140			}
141
142			} else {
143
144			// Update the_host_buffer and copy of the_buffer
145			for (j = y1; j <= y2; j++) {
146	cebix	1.15	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * VideoMonitor.x);
147	cebix	1.6	i += bytes_per_row;
148			}
149	gbeauche	1.1	}
150	cebix	1.15
151	gbeauche	1.1	if (have_shm)
152	cebix	1.15	XShmPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.x, height, 0);
153	gbeauche	1.1	else
154	cebix	1.15	XPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.x, height);
155	gbeauche	1.1	}
156	cebix	1.15
157	gbeauche	1.13	mainBuffer.dirty = false;
158	gbeauche	1.1	}
159
160
161			/*
162			* Update display for DGA mode and VOSF
163			* (only in Direct Addressing mode)
164			*/
165
166			#if REAL_ADDRESSING \|\| DIRECT_ADDRESSING
167			static inline void update_display_dga_vosf(void)
168			{
169			int page = 0;
170			for (;;) {
171	gbeauche	1.11	const int first_page = find_next_page_set(page);
172			if (first_page >= mainBuffer.pageCount)
173	gbeauche	1.1	break;
174	gbeauche	1.11
175			page = find_next_page_clear(first_page);
176			PFLAG_CLEAR_RANGE(first_page, page);
177
178	gbeauche	1.1	// Make the dirty pages read-only again
179			const int32 offset = first_page << mainBuffer.pageBits;
180			const uint32 length = (page - first_page) << mainBuffer.pageBits;
181	gbeauche	1.17	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
182	gbeauche	1.1
183			// I am sure that y2 >= y1 and depth != 1
184			const int y1 = mainBuffer.pageInfo[first_page].top;
185			const int y2 = mainBuffer.pageInfo[page - 1].bottom;
186
187			const int bytes_per_row = VideoMonitor.bytes_per_row;
188			const int bytes_per_pixel = VideoMonitor.bytes_per_row / VideoMonitor.x;
189			int i, j;
190
191			// Check for first column from left and first column
192			// from right that have changed
193			int x1 = VideoMonitor.x * bytes_per_pixel - 1;
194			for (j = y1; j <= y2; j++) {
195			uint8 * const p1 = &the_buffer[j * bytes_per_row];
196			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
197			for (i = 0; i < x1; i++) {
198			if (p1[i] != p2[i]) {
199			x1 = i;
200			break;
201			}
202			}
203			}
204			x1 /= bytes_per_pixel;
205
206			int x2 = x1 * bytes_per_pixel;
207			for (j = y2; j >= y1; j--) {
208			uint8 * const p1 = &the_buffer[j * bytes_per_row];
209			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
210			for (i = VideoMonitor.x * bytes_per_pixel - 1; i > x2; i--) {
211			if (p1[i] != p2[i]) {
212			x2 = i;
213			break;
214			}
215			}
216			}
217			x2 /= bytes_per_pixel;
218
219			// Update the_host_buffer and copy of the_buffer
220			// There should be at least one pixel to copy
221			const int width = x2 - x1 + 1;
222			i = y1 * bytes_per_row + x1 * bytes_per_pixel;
223			for (j = y1; j <= y2; j++) {
224	gbeauche	1.13	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width);
225	gbeauche	1.1	memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width);
226			i += bytes_per_row;
227			}
228			}
229	gbeauche	1.13	mainBuffer.dirty = false;
230	gbeauche	1.1	}
231			#endif
232
233			#endif /* ENABLE_VOSF */
234
235			#endif /* VIDEO_VOSF_H */