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

#include <fcntl.h>
#include <sys/mman.h>
#include "sigsegv.h"
#include "vm_alloc.h"

#ifdef ENABLE_MON
# include "mon.h"
#endif

// Variables for Video on SEGV support
static uint8 *the_host_buffer;  // Host frame buffer in VOSF mode
static uint32 the_buffer_size;  // Size of allocated the_buffer

struct ScreenPageInfo {
    int top, bottom;                    // Mapping between this virtual page and Mac scanlines
};

struct ScreenInfo {
    uintptr memBase;                    // Real start address 
    uintptr memStart;                   // Start address aligned to page boundary
    uintptr memEnd;                             // Address of one-past-the-end of the screen
    uint32 memLength;                   // Length of the memory addressed by the screen pages
    
    uint32 pageSize;                    // Size of a page
    int pageBits;                               // Shift count to get the page number
    uint32 pageCount;                   // Number of pages allocated to the screen
    
        bool dirty;                                     // Flag: set if the frame buffer was touched
    char * dirtyPages;                  // Table of flags set if page was altered
    ScreenPageInfo * pageInfo;  // Table of mappings page -> Mac scanlines
};

static ScreenInfo mainBuffer;

#define PFLAG_SET_VALUE                 0x00
#define PFLAG_CLEAR_VALUE               0x01
#define PFLAG_SET_VALUE_4               0x00000000
#define PFLAG_CLEAR_VALUE_4             0x01010101
#define PFLAG_SET(page)                 mainBuffer.dirtyPages[page] = PFLAG_SET_VALUE
#define PFLAG_CLEAR(page)               mainBuffer.dirtyPages[page] = PFLAG_CLEAR_VALUE
#define PFLAG_ISSET(page)               (mainBuffer.dirtyPages[page] == PFLAG_SET_VALUE)
#define PFLAG_ISCLEAR(page)             (mainBuffer.dirtyPages[page] != PFLAG_SET_VALUE)

#ifdef UNALIGNED_PROFITABLE
# define PFLAG_ISSET_4(page)    (*((uint32 *)(mainBuffer.dirtyPages + (page))) == PFLAG_SET_VALUE_4)
# define PFLAG_ISCLEAR_4(page)  (*((uint32 *)(mainBuffer.dirtyPages + (page))) == PFLAG_CLEAR_VALUE_4)
#else
# define PFLAG_ISSET_4(page) \
                PFLAG_ISSET(page  ) && PFLAG_ISSET(page+1) \
        &&      PFLAG_ISSET(page+2) && PFLAG_ISSET(page+3)
# define PFLAG_ISCLEAR_4(page) \
                PFLAG_ISCLEAR(page  ) && PFLAG_ISCLEAR(page+1) \
        &&      PFLAG_ISCLEAR(page+2) && PFLAG_ISCLEAR(page+3)
#endif

// Set the selected page range [ first_page, last_page [ into the SET state
#define PFLAG_SET_RANGE(first_page, last_page) \
        memset(mainBuffer.dirtyPages + (first_page), PFLAG_SET_VALUE, \
                (last_page) - (first_page))

// Set the selected page range [ first_page, last_page [ into the CLEAR state
#define PFLAG_CLEAR_RANGE(first_page, last_page) \
        memset(mainBuffer.dirtyPages + (first_page), PFLAG_CLEAR_VALUE, \
                (last_page) - (first_page))

#define PFLAG_SET_ALL do { \
        PFLAG_SET_RANGE(0, mainBuffer.pageCount); \
        mainBuffer.dirty = true; \
} while (0)

#define PFLAG_CLEAR_ALL do { \
        PFLAG_CLEAR_RANGE(0, mainBuffer.pageCount); \
        mainBuffer.dirty = false; \
} while (0)

// Set the following macro definition to 1 if your system
// provides a really fast strchr() implementation
//#define HAVE_FAST_STRCHR 0

static inline int find_next_page_set(int page)
{
#if HAVE_FAST_STRCHR
        char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_SET_VALUE);
        return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
#else
        while (PFLAG_ISCLEAR_4(page))
                page += 4;
        while (PFLAG_ISCLEAR(page))
                page++;
        return page;
#endif
}

static inline int find_next_page_clear(int page)
{
#if HAVE_FAST_STRCHR
        char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_CLEAR_VALUE);
        return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
#else
        while (PFLAG_ISSET_4(page))
                page += 4;
        while (PFLAG_ISSET(page))
                page++;
        return page;
#endif
}

#ifdef HAVE_PTHREADS
static pthread_mutex_t vosf_lock = PTHREAD_MUTEX_INITIALIZER;   // Mutex to protect frame buffer (dirtyPages in fact)
#define LOCK_VOSF pthread_mutex_lock(&vosf_lock);
#define UNLOCK_VOSF pthread_mutex_unlock(&vosf_lock);
#else
#define LOCK_VOSF
#define UNLOCK_VOSF
#endif

static int log_base_2(uint32 x)
{
        uint32 mask = 0x80000000;
        int l = 31;
        while (l >= 0 && (x & mask) == 0) {
                mask >>= 1;
                l--;
        }
        return l;
}

// 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;
}


/*
 *  Initialize mainBuffer structure
 */

static bool video_init_buffer(void)
{
        if (use_vosf) {
                const uint32 page_size  = getpagesize();
                const uint32 page_mask  = page_size - 1;
                
                mainBuffer.memBase      = (uintptr) the_buffer;
                // Round up frame buffer base to page boundary
                mainBuffer.memStart             = (uintptr)((((unsigned long) the_buffer) + page_mask) & ~page_mask);
                mainBuffer.memLength    = the_buffer_size;
                mainBuffer.memEnd       = mainBuffer.memStart + mainBuffer.memLength;

                mainBuffer.pageSize     = page_size;
                mainBuffer.pageCount    = (mainBuffer.memLength + page_mask)/mainBuffer.pageSize;
                mainBuffer.pageBits     = log_base_2(mainBuffer.pageSize);

                if (mainBuffer.dirtyPages) {
                        free(mainBuffer.dirtyPages);
                        mainBuffer.dirtyPages = NULL;
                }

                mainBuffer.dirtyPages = (char *) malloc(mainBuffer.pageCount + 2);

                if (mainBuffer.pageInfo) {
                        free(mainBuffer.pageInfo);
                        mainBuffer.pageInfo = NULL;
                }

                mainBuffer.pageInfo = (ScreenPageInfo *) malloc(mainBuffer.pageCount * sizeof(ScreenPageInfo));

                if ((mainBuffer.dirtyPages == 0) || (mainBuffer.pageInfo == 0))
                        return false;
                
                mainBuffer.dirty = false;

                PFLAG_CLEAR_ALL;
                // Safety net to insure the loops in the update routines will terminate
                // See "How can we deal with array overrun conditions ?" hereunder for further details
                PFLAG_CLEAR(mainBuffer.pageCount);
                PFLAG_SET(mainBuffer.pageCount+1);

                uint32 a = 0;
                for (int i = 0; i < mainBuffer.pageCount; i++) {
                        int y1 = a / VideoMonitor.mode.bytes_per_row;
                        if (y1 >= VideoMonitor.mode.y)
                                y1 = VideoMonitor.mode.y - 1;

                        int y2 = (a + mainBuffer.pageSize) / VideoMonitor.mode.bytes_per_row;
                        if (y2 >= VideoMonitor.mode.y)
                                y2 = VideoMonitor.mode.y - 1;

                        mainBuffer.pageInfo[i].top = y1;
                        mainBuffer.pageInfo[i].bottom = y2;

                        a += mainBuffer.pageSize;
                        if (a > mainBuffer.memLength)
                                a = mainBuffer.memLength;
                }
                
                // We can now write-protect the frame buffer
                if (vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ) != 0)
                        return false;
        }
        return true;
}


/*
 * 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 to. 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");
#if EMULATED_68K
        uaecptr nextpc;
        extern void m68k_dumpstate(uaecptr *nextpc);
        m68k_dumpstate(&nextpc);
#endif
#ifdef ENABLE_MON
        char *arg[4] = {"mon", "-m", "-r", NULL};
        mon(3, arg);
        QuitEmulator();
#endif
        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.mode.bytes_per_row;
                const int bytes_per_pixel = VideoMonitor.mode.bytes_per_row / VideoMonitor.mode.x;
                int i = y1 * bytes_per_row, j;
                
                if (VideoMonitor.mode.depth == VDEPTH_1BIT) {

                        // 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.mode.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.mode.x);
                                i += bytes_per_row;
                        }
                }

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


/*
 *      Update display for DGA mode and VOSF
 *      (only in Real or 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.mode.bytes_per_row;
                const int bytes_per_pixel = VideoMonitor.mode.bytes_per_row / VideoMonitor.mode.x;
                int i, j;
                
                // Check for first column from left and first column
                // from right that have changed
                int x1 = VideoMonitor.mode.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.mode.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:	1.20
Committed:	2001-06-28T22:06:18Z (23 years, 4 months ago) by gbeauche
Content type:	text/plain
Branch:	MAIN
Changes since 1.19:	+16 -19 lines
Log Message:	zero_fd is not longer used since vm_alloc.cpp should handle that correctly. However, vm_init() and vm_exit() are called in main_unix.cpp to ensure proper initialization of the internal zero_fd descriptor, if needed. i.e. no anonymous mapping for mmap()-based memory allocation.
#	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	cebix	1.19	#include <fcntl.h>
28			#include <sys/mman.h>
29			#include "sigsegv.h"
30			#include "vm_alloc.h"
31
32			#ifdef ENABLE_MON
33			# include "mon.h"
34			#endif
35
36			// Variables for Video on SEGV support
37	gbeauche	1.20	static uint8 *the_host_buffer; // Host frame buffer in VOSF mode
38			static uint32 the_buffer_size; // Size of allocated the_buffer
39	cebix	1.19
40			struct ScreenPageInfo {
41			int top, bottom; // Mapping between this virtual page and Mac scanlines
42			};
43
44			struct ScreenInfo {
45			uintptr memBase; // Real start address
46			uintptr memStart; // Start address aligned to page boundary
47			uintptr memEnd; // Address of one-past-the-end of the screen
48			uint32 memLength; // Length of the memory addressed by the screen pages
49
50			uint32 pageSize; // Size of a page
51			int pageBits; // Shift count to get the page number
52			uint32 pageCount; // Number of pages allocated to the screen
53
54			bool dirty; // Flag: set if the frame buffer was touched
55			char * dirtyPages; // Table of flags set if page was altered
56			ScreenPageInfo * pageInfo; // Table of mappings page -> Mac scanlines
57			};
58
59			static ScreenInfo mainBuffer;
60
61			#define PFLAG_SET_VALUE 0x00
62			#define PFLAG_CLEAR_VALUE 0x01
63			#define PFLAG_SET_VALUE_4 0x00000000
64			#define PFLAG_CLEAR_VALUE_4 0x01010101
65			#define PFLAG_SET(page) mainBuffer.dirtyPages[page] = PFLAG_SET_VALUE
66			#define PFLAG_CLEAR(page) mainBuffer.dirtyPages[page] = PFLAG_CLEAR_VALUE
67			#define PFLAG_ISSET(page) (mainBuffer.dirtyPages[page] == PFLAG_SET_VALUE)
68			#define PFLAG_ISCLEAR(page) (mainBuffer.dirtyPages[page] != PFLAG_SET_VALUE)
69
70			#ifdef UNALIGNED_PROFITABLE
71			# define PFLAG_ISSET_4(page) (((uint32 )(mainBuffer.dirtyPages + (page))) == PFLAG_SET_VALUE_4)
72			# define PFLAG_ISCLEAR_4(page) (((uint32 )(mainBuffer.dirtyPages + (page))) == PFLAG_CLEAR_VALUE_4)
73			#else
74			# define PFLAG_ISSET_4(page) \
75			PFLAG_ISSET(page ) && PFLAG_ISSET(page+1) \
76			&& PFLAG_ISSET(page+2) && PFLAG_ISSET(page+3)
77			# define PFLAG_ISCLEAR_4(page) \
78			PFLAG_ISCLEAR(page ) && PFLAG_ISCLEAR(page+1) \
79			&& PFLAG_ISCLEAR(page+2) && PFLAG_ISCLEAR(page+3)
80			#endif
81
82			// Set the selected page range [ first_page, last_page [ into the SET state
83			#define PFLAG_SET_RANGE(first_page, last_page) \
84			memset(mainBuffer.dirtyPages + (first_page), PFLAG_SET_VALUE, \
85			(last_page) - (first_page))
86
87			// Set the selected page range [ first_page, last_page [ into the CLEAR state
88			#define PFLAG_CLEAR_RANGE(first_page, last_page) \
89			memset(mainBuffer.dirtyPages + (first_page), PFLAG_CLEAR_VALUE, \
90			(last_page) - (first_page))
91
92			#define PFLAG_SET_ALL do { \
93			PFLAG_SET_RANGE(0, mainBuffer.pageCount); \
94			mainBuffer.dirty = true; \
95			} while (0)
96
97			#define PFLAG_CLEAR_ALL do { \
98			PFLAG_CLEAR_RANGE(0, mainBuffer.pageCount); \
99			mainBuffer.dirty = false; \
100			} while (0)
101
102			// Set the following macro definition to 1 if your system
103			// provides a really fast strchr() implementation
104			//#define HAVE_FAST_STRCHR 0
105
106			static inline int find_next_page_set(int page)
107			{
108			#if HAVE_FAST_STRCHR
109			char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_SET_VALUE);
110			return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
111			#else
112			while (PFLAG_ISCLEAR_4(page))
113			page += 4;
114			while (PFLAG_ISCLEAR(page))
115			page++;
116			return page;
117			#endif
118			}
119
120			static inline int find_next_page_clear(int page)
121			{
122			#if HAVE_FAST_STRCHR
123			char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_CLEAR_VALUE);
124			return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
125			#else
126			while (PFLAG_ISSET_4(page))
127			page += 4;
128			while (PFLAG_ISSET(page))
129			page++;
130			return page;
131			#endif
132			}
133
134			#ifdef HAVE_PTHREADS
135			static pthread_mutex_t vosf_lock = PTHREAD_MUTEX_INITIALIZER; // Mutex to protect frame buffer (dirtyPages in fact)
136			#define LOCK_VOSF pthread_mutex_lock(&vosf_lock);
137			#define UNLOCK_VOSF pthread_mutex_unlock(&vosf_lock);
138			#else
139			#define LOCK_VOSF
140			#define UNLOCK_VOSF
141			#endif
142
143			static int log_base_2(uint32 x)
144			{
145			uint32 mask = 0x80000000;
146			int l = 31;
147			while (l >= 0 && (x & mask) == 0) {
148			mask >>= 1;
149			l--;
150			}
151			return l;
152			}
153
154	gbeauche	1.20	// Extend size to page boundary
155			static uint32 page_extend(uint32 size)
156			{
157			const uint32 page_size = getpagesize();
158			const uint32 page_mask = page_size - 1;
159			return (size + page_mask) & ~page_mask;
160			}
161
162	cebix	1.19
163			/*
164			* Initialize mainBuffer structure
165			*/
166
167			static bool video_init_buffer(void)
168			{
169			if (use_vosf) {
170			const uint32 page_size = getpagesize();
171			const uint32 page_mask = page_size - 1;
172
173			mainBuffer.memBase = (uintptr) the_buffer;
174	gbeauche	1.20	// Round up frame buffer base to page boundary
175	cebix	1.19	mainBuffer.memStart = (uintptr)((((unsigned long) the_buffer) + page_mask) & ~page_mask);
176			mainBuffer.memLength = the_buffer_size;
177			mainBuffer.memEnd = mainBuffer.memStart + mainBuffer.memLength;
178
179			mainBuffer.pageSize = page_size;
180			mainBuffer.pageCount = (mainBuffer.memLength + page_mask)/mainBuffer.pageSize;
181			mainBuffer.pageBits = log_base_2(mainBuffer.pageSize);
182
183			if (mainBuffer.dirtyPages) {
184			free(mainBuffer.dirtyPages);
185			mainBuffer.dirtyPages = NULL;
186			}
187
188			mainBuffer.dirtyPages = (char *) malloc(mainBuffer.pageCount + 2);
189
190			if (mainBuffer.pageInfo) {
191			free(mainBuffer.pageInfo);
192			mainBuffer.pageInfo = NULL;
193			}
194
195			mainBuffer.pageInfo = (ScreenPageInfo ) malloc(mainBuffer.pageCount sizeof(ScreenPageInfo));
196
197			if ((mainBuffer.dirtyPages == 0) \|\| (mainBuffer.pageInfo == 0))
198			return false;
199
200			mainBuffer.dirty = false;
201
202			PFLAG_CLEAR_ALL;
203			// Safety net to insure the loops in the update routines will terminate
204	gbeauche	1.20	// See "How can we deal with array overrun conditions ?" hereunder for further details
205	cebix	1.19	PFLAG_CLEAR(mainBuffer.pageCount);
206			PFLAG_SET(mainBuffer.pageCount+1);
207
208			uint32 a = 0;
209			for (int i = 0; i < mainBuffer.pageCount; i++) {
210			int y1 = a / VideoMonitor.mode.bytes_per_row;
211			if (y1 >= VideoMonitor.mode.y)
212			y1 = VideoMonitor.mode.y - 1;
213
214			int y2 = (a + mainBuffer.pageSize) / VideoMonitor.mode.bytes_per_row;
215			if (y2 >= VideoMonitor.mode.y)
216			y2 = VideoMonitor.mode.y - 1;
217
218			mainBuffer.pageInfo[i].top = y1;
219			mainBuffer.pageInfo[i].bottom = y2;
220
221			a += mainBuffer.pageSize;
222			if (a > mainBuffer.memLength)
223			a = mainBuffer.memLength;
224			}
225
226			// We can now write-protect the frame buffer
227			if (vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ) != 0)
228			return false;
229			}
230			return true;
231			}
232
233
234	gbeauche	1.1	/*
235	gbeauche	1.20	* Screen fault handler
236	gbeauche	1.1	*/
237
238	gbeauche	1.16	static bool screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction)
239	gbeauche	1.1	{
240	gbeauche	1.16	D(bug("screen_fault_handler: ADDR=0x%08X from IP=0x%08X\n", fault_address, fault_instruction));
241			const uintptr addr = (uintptr)fault_address;
242
243	gbeauche	1.11	/* Someone attempted to write to the frame buffer. Make it writeable
244	gbeauche	1.20	* now so that the data could actually be written to. It will be made
245	gbeauche	1.11	* read-only back in one of the screen update_*() functions.
246			*/
247			if ((addr >= mainBuffer.memStart) && (addr < mainBuffer.memEnd)) {
248			const int page = (addr - mainBuffer.memStart) >> mainBuffer.pageBits;
249	gbeauche	1.17	caddr_t page_ad = (caddr_t)(addr & -mainBuffer.pageSize);
250	gbeauche	1.11	LOCK_VOSF;
251			PFLAG_SET(page);
252	gbeauche	1.17	vm_protect((char *)page_ad, mainBuffer.pageSize, VM_PAGE_READ \| VM_PAGE_WRITE);
253	gbeauche	1.13	mainBuffer.dirty = true;
254	gbeauche	1.11	UNLOCK_VOSF;
255	gbeauche	1.16	return true;
256	gbeauche	1.1	}
257
258	gbeauche	1.11	/* Otherwise, we don't know how to handle the fault, let it crash */
259			fprintf(stderr, "do_handle_screen_fault: unhandled address 0x%08X", addr);
260	gbeauche	1.16	if (fault_instruction != SIGSEGV_INVALID_PC)
261			fprintf(stderr, " [IP=0x%08X]", fault_instruction);
262	gbeauche	1.11	fprintf(stderr, "\n");
263	cebix	1.19	#if EMULATED_68K
264			uaecptr nextpc;
265			extern void m68k_dumpstate(uaecptr *nextpc);
266			m68k_dumpstate(&nextpc);
267			#endif
268			#ifdef ENABLE_MON
269			char *arg[4] = {"mon", "-m", "-r", NULL};
270			mon(3, arg);
271			QuitEmulator();
272			#endif
273	gbeauche	1.16	return false;
274	gbeauche	1.1	}
275
276	gbeauche	1.20
277	gbeauche	1.1	/*
278			* Update display for Windowed mode and VOSF
279			*/
280
281	gbeauche	1.13	// From video_blit.cpp
282			extern void (Screen_blit)(uint8 dest, const uint8 * source, uint32 length);
283			extern bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order);
284
285	gbeauche	1.12	/* How can we deal with array overrun conditions ?
286
287			The state of the framebuffer pages that have been touched are maintained
288			in the dirtyPages[] table. That table is (pageCount + 2) bytes long.
289
290			Terminology
291
292			"Last Page" denotes the pageCount-nth page, i.e. dirtyPages[pageCount - 1].
293			"CLEAR Page Guard" refers to the page following the Last Page but is always
294			in the CLEAR state. "SET Page Guard" refers to the page following the CLEAR
295			Page Guard but is always in the SET state.
296
297			Rough process
298
299	gbeauche	1.13	The update routines must determine which pages have to be blitted to the
300	gbeauche	1.12	screen. This job consists in finding the first_page that was touched.
301			i.e. find the next page that is SET. Then, finding how many pages were
302			touched starting from first_page. i.e. find the next page that is CLEAR.
303
304	gbeauche	1.13	There are two cases to check:
305	gbeauche	1.12
306			- Last Page is CLEAR: find_next_page_set() will reach the SET Page Guard
307			but it is beyond the valid pageCount value. Therefore, we exit from the
308			update routine.
309
310			- Last Page is SET: first_page equals (pageCount - 1) and
311			find_next_page_clear() will reach the CLEAR Page Guard. We blit the last
312			page to the screen. On the next iteration, page equals pageCount and
313			find_next_page_set() will reach the SET Page Guard. We still safely exit
314			from the update routine because the SET Page Guard position is greater
315			than pageCount.
316			*/
317
318	gbeauche	1.1	static inline void update_display_window_vosf(void)
319			{
320			int page = 0;
321			for (;;) {
322	gbeauche	1.11	const int first_page = find_next_page_set(page);
323			if (first_page >= mainBuffer.pageCount)
324	gbeauche	1.1	break;
325	gbeauche	1.11
326			page = find_next_page_clear(first_page);
327			PFLAG_CLEAR_RANGE(first_page, page);
328	cebix	1.7
329	gbeauche	1.1	// Make the dirty pages read-only again
330			const int32 offset = first_page << mainBuffer.pageBits;
331			const uint32 length = (page - first_page) << mainBuffer.pageBits;
332	gbeauche	1.17	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
333	gbeauche	1.1
334			// There is at least one line to update
335			const int y1 = mainBuffer.pageInfo[first_page].top;
336			const int y2 = mainBuffer.pageInfo[page - 1].bottom;
337			const int height = y2 - y1 + 1;
338
339	cebix	1.18	const int bytes_per_row = VideoMonitor.mode.bytes_per_row;
340			const int bytes_per_pixel = VideoMonitor.mode.bytes_per_row / VideoMonitor.mode.x;
341	cebix	1.15	int i = y1 * bytes_per_row, j;
342	gbeauche	1.1
343	cebix	1.19	if (VideoMonitor.mode.depth == VDEPTH_1BIT) {
344	cebix	1.6
345			// Update the_host_buffer and copy of the_buffer
346			for (j = y1; j <= y2; j++) {
347	cebix	1.18	Screen_blit(the_host_buffer + i, the_buffer + i, VideoMonitor.mode.x >> 3);
348	cebix	1.6	i += bytes_per_row;
349			}
350
351			} else {
352
353			// Update the_host_buffer and copy of the_buffer
354			for (j = y1; j <= y2; j++) {
355	cebix	1.18	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * VideoMonitor.mode.x);
356	cebix	1.6	i += bytes_per_row;
357			}
358	gbeauche	1.1	}
359	cebix	1.15
360	gbeauche	1.1	if (have_shm)
361	cebix	1.18	XShmPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.mode.x, height, 0);
362	gbeauche	1.1	else
363	cebix	1.18	XPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.mode.x, height);
364	gbeauche	1.1	}
365	gbeauche	1.13	mainBuffer.dirty = false;
366	gbeauche	1.1	}
367
368
369			/*
370			* Update display for DGA mode and VOSF
371	gbeauche	1.20	* (only in Real or Direct Addressing mode)
372	gbeauche	1.1	*/
373
374			#if REAL_ADDRESSING \|\| DIRECT_ADDRESSING
375			static inline void update_display_dga_vosf(void)
376			{
377			int page = 0;
378			for (;;) {
379	gbeauche	1.11	const int first_page = find_next_page_set(page);
380			if (first_page >= mainBuffer.pageCount)
381	gbeauche	1.1	break;
382	gbeauche	1.11
383			page = find_next_page_clear(first_page);
384			PFLAG_CLEAR_RANGE(first_page, page);
385
386	gbeauche	1.1	// Make the dirty pages read-only again
387			const int32 offset = first_page << mainBuffer.pageBits;
388			const uint32 length = (page - first_page) << mainBuffer.pageBits;
389	gbeauche	1.17	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
390	gbeauche	1.1
391			// I am sure that y2 >= y1 and depth != 1
392			const int y1 = mainBuffer.pageInfo[first_page].top;
393			const int y2 = mainBuffer.pageInfo[page - 1].bottom;
394
395	cebix	1.18	const int bytes_per_row = VideoMonitor.mode.bytes_per_row;
396			const int bytes_per_pixel = VideoMonitor.mode.bytes_per_row / VideoMonitor.mode.x;
397	gbeauche	1.1	int i, j;
398
399			// Check for first column from left and first column
400			// from right that have changed
401	cebix	1.18	int x1 = VideoMonitor.mode.x * bytes_per_pixel - 1;
402	gbeauche	1.1	for (j = y1; j <= y2; j++) {
403			uint8 * const p1 = &the_buffer[j * bytes_per_row];
404			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
405			for (i = 0; i < x1; i++) {
406			if (p1[i] != p2[i]) {
407			x1 = i;
408			break;
409			}
410			}
411			}
412			x1 /= bytes_per_pixel;
413
414			int x2 = x1 * bytes_per_pixel;
415			for (j = y2; j >= y1; j--) {
416			uint8 * const p1 = &the_buffer[j * bytes_per_row];
417			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
418	cebix	1.18	for (i = VideoMonitor.mode.x * bytes_per_pixel - 1; i > x2; i--) {
419	gbeauche	1.1	if (p1[i] != p2[i]) {
420			x2 = i;
421			break;
422			}
423			}
424			}
425			x2 /= bytes_per_pixel;
426
427			// Update the_host_buffer and copy of the_buffer
428			// There should be at least one pixel to copy
429			const int width = x2 - x1 + 1;
430			i = y1 * bytes_per_row + x1 * bytes_per_pixel;
431			for (j = y1; j <= y2; j++) {
432	gbeauche	1.13	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width);
433	gbeauche	1.1	memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width);
434			i += bytes_per_row;
435			}
436			}
437	gbeauche	1.13	mainBuffer.dirty = false;
438	gbeauche	1.1	}
439			#endif
440
441			#endif /* ENABLE_VOSF */
442
443			#endif /* VIDEO_VOSF_H */