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, 3 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
#	Content
1	/*
2	* video_vosf.h - Video/graphics emulation, video on SEGV signals support
3	*
4	* Basilisk II (C) 1997-2001 Christian Bauer
5	*
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	// Extend size to page boundary
32	static uint32 page_extend(uint32 size)
33	{
34	const uint32 page_size = getpagesize();
35	const uint32 page_mask = page_size - 1;
36	return (size + page_mask) & ~page_mask;
37	}
38
39	// Screen fault handler
40	static bool screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction)
41	{
42	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	/* 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	caddr_t page_ad = (caddr_t)(addr & -mainBuffer.pageSize);
52	LOCK_VOSF;
53	PFLAG_SET(page);
54	vm_protect((char *)page_ad, mainBuffer.pageSize, VM_PAGE_READ \| VM_PAGE_WRITE);
55	mainBuffer.dirty = true;
56	UNLOCK_VOSF;
57	return true;
58	}
59
60	/* 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	if (fault_instruction != SIGSEGV_INVALID_PC)
63	fprintf(stderr, " [IP=0x%08X]", fault_instruction);
64	fprintf(stderr, "\n");
65	return false;
66	}
67
68	/*
69	* Update display for Windowed mode and VOSF
70	*/
71
72	// 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	/* 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	The update routines must determine which pages have to be blitted to the
91	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	There are two cases to check:
96
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	static inline void update_display_window_vosf(void)
110	{
111	int page = 0;
112	for (;;) {
113	const int first_page = find_next_page_set(page);
114	if (first_page >= mainBuffer.pageCount)
115	break;
116
117	page = find_next_page_clear(first_page);
118	PFLAG_CLEAR_RANGE(first_page, page);
119
120	// 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	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
124
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	int i = y1 * bytes_per_row, j;
133
134	if (depth == 1) {
135
136	// Update the_host_buffer and copy of the_buffer
137	for (j = y1; j <= y2; j++) {
138	Screen_blit(the_host_buffer + i, the_buffer + i, VideoMonitor.x >> 3);
139	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	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * VideoMonitor.x);
147	i += bytes_per_row;
148	}
149	}
150
151	if (have_shm)
152	XShmPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.x, height, 0);
153	else
154	XPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.x, height);
155	}
156
157	mainBuffer.dirty = false;
158	}
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	const int first_page = find_next_page_set(page);
172	if (first_page >= mainBuffer.pageCount)
173	break;
174
175	page = find_next_page_clear(first_page);
176	PFLAG_CLEAR_RANGE(first_page, page);
177
178	// 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	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
182
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	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width);
225	memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width);
226	i += bytes_per_row;
227	}
228	}
229	mainBuffer.dirty = false;
230	}
231	#endif
232
233	#endif /* ENABLE_VOSF */
234
235	#endif /* VIDEO_VOSF_H */