hw/syborg_fb.c - qemu - Git at Google

 /*
  * Syborg Framebuffer
  *
  * Copyright (c) 2009 CodeSourcery
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include "sysbus.h"
 #include "console.h"
 #include "syborg.h"
 #include "framebuffer.h"

 //#define DEBUG_SYBORG_FB

 #ifdef DEBUG_SYBORG_FB
 #define DPRINTF(fmt, ...) \
 do { printf("syborg_fb: " fmt , ## __VA_ARGS__); } while (0)
 #define BADF(fmt, ...) \
 do { fprintf(stderr, "syborg_fb: error: " fmt , ## __VA_ARGS__); \
     exit(1);} while (0)
 #else
 #define DPRINTF(fmt, ...) do {} while(0)
 #define BADF(fmt, ...) \
 do { fprintf(stderr, "syborg_fb: error: " fmt , ## __VA_ARGS__);} while (0)
 #endif

 enum {
     FB_ID               = 0,
     FB_BASE             = 1,
     FB_HEIGHT           = 2,
     FB_WIDTH            = 3,
     FB_ORIENTATION      = 4,
     FB_BLANK            = 5,
     FB_INT_MASK         = 6,
     FB_INTERRUPT_CAUSE  = 7,
     FB_BPP              = 8,
     FB_COLOR_ORDER      = 9,
     FB_BYTE_ORDER       = 10,
     FB_PIXEL_ORDER      = 11,
     FB_ROW_PITCH        = 12,
     FB_ENABLED          = 13,
     FB_PALETTE_START    = 0x400 >> 2,
     FB_PALETTE_END   = FB_PALETTE_START+256-1,
 };

 #define FB_INT_VSYNC            (1U << 0)
 #define FB_INT_BASE_UPDATE_DONE (1U << 1)

 typedef struct {
     SysBusDevice busdev;
     DisplayState *ds;
     /*QEMUConsole *console;*/
     uint32_t need_update : 1;
     uint32_t need_int : 1;
     uint32_t enabled : 1;
     uint32_t int_status;
     uint32_t int_enable;
     qemu_irq irq;

     uint32_t base;
     uint32_t pitch;
     uint32_t rows;
     uint32_t cols;
     int blank;
     int bpp;
     int rgb; /* 0 = BGR, 1 = RGB */
     int endian; /* 0 = Little, 1 = Big */
     uint32_t raw_palette[256];
     uint32_t palette[256];
 } SyborgFBState;

 enum {
     BPP_SRC_1,
     BPP_SRC_2,
     BPP_SRC_4,
     BPP_SRC_8,
     BPP_SRC_16,
     BPP_SRC_32,
     /* TODO: Implement these.  */
     BPP_SRC_15 = -1,
     BPP_SRC_24 = -2
 };

 #include "pixel_ops.h"

 #define BITS 8
 #include "pl110_template.h"
 #define BITS 15
 #include "pl110_template.h"
 #define BITS 16
 #include "pl110_template.h"
 #define BITS 24
 #include "pl110_template.h"
 #define BITS 32
 #include "pl110_template.h"

 /* Update interrupts.  */
 static void syborg_fb_update(SyborgFBState *s)
 {
     if ((s->int_status & s->int_enable) != 0) {
         DPRINTF("Raise IRQ\n");
         qemu_irq_raise(s->irq);
     } else {
         DPRINTF("Lower IRQ\n");
         qemu_irq_lower(s->irq);
     }
 }

 static int syborg_fb_enabled(const SyborgFBState *s)
 {
     return s->enabled;
 }

 static void syborg_fb_update_palette(SyborgFBState *s)
 {
     int n, i;
     uint32_t raw;
     unsigned int r, g, b;

     switch (s->bpp) {
     case BPP_SRC_1: n = 2; break;
     case BPP_SRC_2: n = 4; break;
     case BPP_SRC_4: n = 16; break;
     case BPP_SRC_8: n = 256; break;
     default: return;
     }

     for (i = 0; i < n; i++) {
         raw = s->raw_palette[i];
         r = (raw >> 16) & 0xff;
         g = (raw >> 8) & 0xff;
         b = raw & 0xff;
         switch (ds_get_bits_per_pixel(s->ds)) {
         case 8:
             s->palette[i] = rgb_to_pixel8(r, g, b);
             break;
         case 15:
             s->palette[i] = rgb_to_pixel15(r, g, b);
             break;
         case 16:
             s->palette[i] = rgb_to_pixel16(r, g, b);
             break;
         case 24:
         case 32:
             s->palette[i] = rgb_to_pixel32(r, g, b);
             break;
         default:
             abort();
         }
     }

 }

 static void syborg_fb_update_display(void *opaque)
 {
     SyborgFBState *s = (SyborgFBState *)opaque;
     drawfn* fntable;
     drawfn fn;
     int dest_width;
     int src_width;
     int bpp_offset;
     int first;
     int last;

     if (!syborg_fb_enabled(s))
         return;

     switch (ds_get_bits_per_pixel(s->ds)) {
     case 0:
         return;
     case 8:
         fntable = pl110_draw_fn_8;
         dest_width = 1;
         break;
     case 15:
         fntable = pl110_draw_fn_15;
         dest_width = 2;
         break;
     case 16:
         fntable = pl110_draw_fn_16;
         dest_width = 2;
         break;
     case 24:
         fntable = pl110_draw_fn_24;
         dest_width = 3;
         break;
     case 32:
         fntable = pl110_draw_fn_32;
         dest_width = 4;
         break;
     default:
         fprintf(stderr, "syborg_fb: Bad color depth\n");
         exit(1);
     }

     if (s->need_int) {
         s->int_status |= FB_INT_BASE_UPDATE_DONE;
         syborg_fb_update(s);
         s->need_int = 0;
     }

     if (s->rgb) {
         bpp_offset = 18;
     } else {
         bpp_offset = 0;
     }
     if (s->endian) {
         bpp_offset += 6;
     }

     fn = fntable[s->bpp + bpp_offset];

     if (s->pitch) {
         src_width = s->pitch;
     } else {
         src_width = s->cols;
         switch (s->bpp) {
         case BPP_SRC_1:
             src_width >>= 3;
             break;
         case BPP_SRC_2:
             src_width >>= 2;
             break;
         case BPP_SRC_4:
             src_width >>= 1;
             break;
         case BPP_SRC_8:
             break;
         case BPP_SRC_15:
         case BPP_SRC_16:
             src_width <<= 1;
             break;
         case BPP_SRC_24:
             src_width *= 3;
             break;
         case BPP_SRC_32:
             src_width <<= 2;
             break;
         }
     }
     dest_width *= s->cols;
     first = 0;
     /* TODO: Implement blanking.  */
     if (!s->blank) {
         if (s->need_update && s->bpp <= BPP_SRC_8) {
             syborg_fb_update_palette(s);
         }
         framebuffer_update_display(s->ds,
                                    s->base, s->cols, s->rows,
                                    src_width, dest_width, 0,
                                    s->need_update,
                                    fn, s->palette,
                                    &first, &last);
         if (first >= 0) {
             dpy_update(s->ds, 0, first, s->cols, last - first + 1);
         }

         s->int_status |= FB_INT_VSYNC;
         syborg_fb_update(s);
     }

     s->need_update = 0;
 }

 static void syborg_fb_invalidate_display(void * opaque)
 {
     SyborgFBState *s = (SyborgFBState *)opaque;
     s->need_update = 1;
 }

 static uint32_t syborg_fb_read(void *opaque, target_phys_addr_t offset)
 {
     SyborgFBState *s = opaque;

     DPRINTF("read reg %d\n", (int)offset);
     offset &= 0xfff;
     switch (offset >> 2) {
     case FB_ID:
         return SYBORG_ID_FRAMEBUFFER;

     case FB_BASE:
         return s->base;

     case FB_HEIGHT:
         return s->rows;

     case FB_WIDTH:
         return s->cols;

     case FB_ORIENTATION:
         return 0;

     case FB_BLANK:
         return s->blank;

     case FB_INT_MASK:
         return s->int_enable;

     case FB_INTERRUPT_CAUSE:
         return s->int_status;

     case FB_BPP:
         switch (s->bpp) {
         case BPP_SRC_1: return 1;
         case BPP_SRC_2: return 2;
         case BPP_SRC_4: return 4;
         case BPP_SRC_8: return 8;
         case BPP_SRC_15: return 15;
         case BPP_SRC_16: return 16;
         case BPP_SRC_24: return 24;
         case BPP_SRC_32: return 32;
         default: return 0;
         }

     case FB_COLOR_ORDER:
         return s->rgb;

     case FB_BYTE_ORDER:
         return s->endian;

     case FB_PIXEL_ORDER:
         return 0;

     case FB_ROW_PITCH:
         return s->pitch;

     case FB_ENABLED:
         return s->enabled;

     default:
         if ((offset >> 2) >= FB_PALETTE_START
             && (offset >> 2) <= FB_PALETTE_END) {
             return s->raw_palette[(offset >> 2) - FB_PALETTE_START];
         } else {
             cpu_abort (cpu_single_env, "syborg_fb_read: Bad offset %x\n",
                          (int)offset);
         }
         return 0;
     }
 }

 static void syborg_fb_write(void *opaque, target_phys_addr_t offset,
                             uint32_t val)
 {
     SyborgFBState *s = opaque;

     DPRINTF("write reg %d = %d\n", (int)offset, val);
     s->need_update = 1;
     offset &= 0xfff;
     switch (offset >> 2) {
     case FB_BASE:
         s->base = val;
         s->need_int = 1;
         s->need_update = 1;
         syborg_fb_update(s);
         break;

     case FB_HEIGHT:
         s->rows = val;
         break;

     case FB_WIDTH:
         s->cols = val;
         break;

     case FB_ORIENTATION:
         /* TODO: Implement rotation.  */
         break;

     case FB_BLANK:
         s->blank = val & 1;
         break;

     case FB_INT_MASK:
         s->int_enable = val;
         syborg_fb_update(s);
         break;

     case FB_INTERRUPT_CAUSE:
         s->int_status &= ~val;
         syborg_fb_update(s);
         break;

     case FB_BPP:
         switch (val) {
         case 1: val = BPP_SRC_1; break;
         case 2: val = BPP_SRC_2; break;
         case 4: val = BPP_SRC_4; break;
         case 8: val = BPP_SRC_8; break;
         /* case 15: val = BPP_SRC_15; break; */
         case 16: val = BPP_SRC_16; break;
         /* case 24: val = BPP_SRC_24; break; */
         case 32: val = BPP_SRC_32; break;
         default: val = s->bpp; break;
         }
         s->bpp = val;
         break;

     case FB_COLOR_ORDER:
         s->rgb = (val != 0);
         break;

     case FB_BYTE_ORDER:
         s->endian = (val != 0);
         break;

     case FB_PIXEL_ORDER:
         /* TODO: Implement this.  */
         break;

     case FB_ROW_PITCH:
         s->pitch = val;
         break;

     case FB_ENABLED:
         s->enabled = val;
         break;

     default:
         if ((offset >> 2) >= FB_PALETTE_START
             && (offset >> 2) <= FB_PALETTE_END) {
             s->raw_palette[(offset >> 2) - FB_PALETTE_START] = val;
         } else {
             cpu_abort (cpu_single_env, "syborg_fb_write: Bad offset %x\n",
                       (int)offset);
         }
         break;
     }
 }

 static CPUReadMemoryFunc * const syborg_fb_readfn[] = {
     syborg_fb_read,
     syborg_fb_read,
     syborg_fb_read
 };

 static CPUWriteMemoryFunc * const syborg_fb_writefn[] = {
     syborg_fb_write,
     syborg_fb_write,
     syborg_fb_write
 };

 static void syborg_fb_save(QEMUFile *f, void *opaque)
 {
     SyborgFBState *s = opaque;
     int i;

     qemu_put_be32(f, s->need_int);
     qemu_put_be32(f, s->int_status);
     qemu_put_be32(f, s->int_enable);
     qemu_put_be32(f, s->enabled);
     qemu_put_be32(f, s->base);
     qemu_put_be32(f, s->pitch);
     qemu_put_be32(f, s->rows);
     qemu_put_be32(f, s->cols);
     qemu_put_be32(f, s->bpp);
     qemu_put_be32(f, s->rgb);
     for (i = 0; i < 256; i++) {
         qemu_put_be32(f, s->raw_palette[i]);
     }
 }

 static int syborg_fb_load(QEMUFile *f, void *opaque, int version_id)
 {
     SyborgFBState *s = opaque;
     int i;

     if (version_id != 1)
         return -EINVAL;

     s->need_int = qemu_get_be32(f);
     s->int_status = qemu_get_be32(f);
     s->int_enable = qemu_get_be32(f);
     s->enabled = qemu_get_be32(f);
     s->base = qemu_get_be32(f);
     s->pitch = qemu_get_be32(f);
     s->rows = qemu_get_be32(f);
     s->cols = qemu_get_be32(f);
     s->bpp = qemu_get_be32(f);
     s->rgb = qemu_get_be32(f);
     for (i = 0; i < 256; i++) {
         s->raw_palette[i] = qemu_get_be32(f);
     }
     s->need_update = 1;

     return 0;
 }

 static int syborg_fb_init(SysBusDevice *dev)
 {
     SyborgFBState *s = FROM_SYSBUS(SyborgFBState, dev);
     int iomemtype;

     sysbus_init_irq(dev, &s->irq);
     iomemtype = cpu_register_io_memory(syborg_fb_readfn,
                                        syborg_fb_writefn, s);
     sysbus_init_mmio(dev, 0x1000, iomemtype);

     s->ds = graphic_console_init(syborg_fb_update_display,
                                  syborg_fb_invalidate_display,
                                  NULL, NULL, s);

     if (s->cols != 0 && s->rows != 0) {
         qemu_console_resize(s->ds, s->cols, s->rows);
     }

     if (!s->cols)
         s->cols = ds_get_width(s->ds);
     if (!s->rows)
         s->rows = ds_get_height(s->ds);

     register_savevm(&dev->qdev, "syborg_framebuffer", -1, 1,
                     syborg_fb_save, syborg_fb_load, s);
     return 0;
 }

 static SysBusDeviceInfo syborg_fb_info = {
     .init = syborg_fb_init,
     .qdev.name  = "syborg,framebuffer",
     .qdev.size  = sizeof(SyborgFBState),
     .qdev.props = (Property[]) {
         DEFINE_PROP_UINT32("width",  SyborgFBState, cols, 0),
         DEFINE_PROP_UINT32("height", SyborgFBState, rows, 0),
         DEFINE_PROP_END_OF_LIST(),
     }
 };

 static void syborg_fb_register_devices(void)
 {
     sysbus_register_withprop(&syborg_fb_info);
 }

 device_init(syborg_fb_register_devices)
	/*
	* Syborg Framebuffer
	*
	* Copyright (c) 2009 CodeSourcery
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include "sysbus.h"
	#include "console.h"
	#include "syborg.h"
	#include "framebuffer.h"

	//#define DEBUG_SYBORG_FB

	#ifdef DEBUG_SYBORG_FB
	#define DPRINTF(fmt, ...) \
	do { printf("syborg_fb: " fmt , ## __VA_ARGS__); } while (0)
	#define BADF(fmt, ...) \
	do { fprintf(stderr, "syborg_fb: error: " fmt , ## __VA_ARGS__); \
	exit(1);} while (0)
	#else
	#define DPRINTF(fmt, ...) do {} while(0)
	#define BADF(fmt, ...) \
	do { fprintf(stderr, "syborg_fb: error: " fmt , ## __VA_ARGS__);} while (0)
	#endif

	enum {
	FB_ID = 0,
	FB_BASE = 1,
	FB_HEIGHT = 2,
	FB_WIDTH = 3,
	FB_ORIENTATION = 4,
	FB_BLANK = 5,
	FB_INT_MASK = 6,
	FB_INTERRUPT_CAUSE = 7,
	FB_BPP = 8,
	FB_COLOR_ORDER = 9,
	FB_BYTE_ORDER = 10,
	FB_PIXEL_ORDER = 11,
	FB_ROW_PITCH = 12,
	FB_ENABLED = 13,
	FB_PALETTE_START = 0x400 >> 2,
	FB_PALETTE_END = FB_PALETTE_START+256-1,
	};

	#define FB_INT_VSYNC (1U << 0)
	#define FB_INT_BASE_UPDATE_DONE (1U << 1)

	typedef struct {
	SysBusDevice busdev;
	DisplayState *ds;
	/QEMUConsole console;*/
	uint32_t need_update : 1;
	uint32_t need_int : 1;
	uint32_t enabled : 1;
	uint32_t int_status;
	uint32_t int_enable;
	qemu_irq irq;

	uint32_t base;
	uint32_t pitch;
	uint32_t rows;
	uint32_t cols;
	int blank;
	int bpp;
	int rgb; /* 0 = BGR, 1 = RGB */
	int endian; /* 0 = Little, 1 = Big */
	uint32_t raw_palette[256];
	uint32_t palette[256];
	} SyborgFBState;

	enum {
	BPP_SRC_1,
	BPP_SRC_2,
	BPP_SRC_4,
	BPP_SRC_8,
	BPP_SRC_16,
	BPP_SRC_32,
	/* TODO: Implement these. */
	BPP_SRC_15 = -1,
	BPP_SRC_24 = -2
	};

	#include "pixel_ops.h"

	#define BITS 8
	#include "pl110_template.h"
	#define BITS 15
	#include "pl110_template.h"
	#define BITS 16
	#include "pl110_template.h"
	#define BITS 24
	#include "pl110_template.h"
	#define BITS 32
	#include "pl110_template.h"

	/* Update interrupts. */
	static void syborg_fb_update(SyborgFBState *s)
	{
	if ((s->int_status & s->int_enable) != 0) {
	DPRINTF("Raise IRQ\n");
	qemu_irq_raise(s->irq);
	} else {
	DPRINTF("Lower IRQ\n");
	qemu_irq_lower(s->irq);
	}
	}

	static int syborg_fb_enabled(const SyborgFBState *s)
	{
	return s->enabled;
	}

	static void syborg_fb_update_palette(SyborgFBState *s)
	{
	int n, i;
	uint32_t raw;
	unsigned int r, g, b;

	switch (s->bpp) {
	case BPP_SRC_1: n = 2; break;
	case BPP_SRC_2: n = 4; break;
	case BPP_SRC_4: n = 16; break;
	case BPP_SRC_8: n = 256; break;
	default: return;
	}

	for (i = 0; i < n; i++) {
	raw = s->raw_palette[i];
	r = (raw >> 16) & 0xff;
	g = (raw >> 8) & 0xff;
	b = raw & 0xff;
	switch (ds_get_bits_per_pixel(s->ds)) {
	case 8:
	s->palette[i] = rgb_to_pixel8(r, g, b);
	break;
	case 15:
	s->palette[i] = rgb_to_pixel15(r, g, b);
	break;
	case 16:
	s->palette[i] = rgb_to_pixel16(r, g, b);
	break;
	case 24:
	case 32:
	s->palette[i] = rgb_to_pixel32(r, g, b);
	break;
	default:
	abort();
	}
	}

	}

	static void syborg_fb_update_display(void *opaque)
	{
	SyborgFBState s = (SyborgFBState )opaque;
	drawfn* fntable;
	drawfn fn;
	int dest_width;
	int src_width;
	int bpp_offset;
	int first;
	int last;

	if (!syborg_fb_enabled(s))
	return;

	switch (ds_get_bits_per_pixel(s->ds)) {
	case 0:
	return;
	case 8:
	fntable = pl110_draw_fn_8;
	dest_width = 1;
	break;
	case 15:
	fntable = pl110_draw_fn_15;
	dest_width = 2;
	break;
	case 16:
	fntable = pl110_draw_fn_16;
	dest_width = 2;
	break;
	case 24:
	fntable = pl110_draw_fn_24;
	dest_width = 3;
	break;
	case 32:
	fntable = pl110_draw_fn_32;
	dest_width = 4;
	break;
	default:
	fprintf(stderr, "syborg_fb: Bad color depth\n");
	exit(1);
	}

	if (s->need_int) {
	s->int_status \|= FB_INT_BASE_UPDATE_DONE;
	syborg_fb_update(s);
	s->need_int = 0;
	}

	if (s->rgb) {
	bpp_offset = 18;
	} else {
	bpp_offset = 0;
	}
	if (s->endian) {
	bpp_offset += 6;
	}

	fn = fntable[s->bpp + bpp_offset];

	if (s->pitch) {
	src_width = s->pitch;
	} else {
	src_width = s->cols;
	switch (s->bpp) {
	case BPP_SRC_1:
	src_width >>= 3;
	break;
	case BPP_SRC_2:
	src_width >>= 2;
	break;
	case BPP_SRC_4:
	src_width >>= 1;
	break;
	case BPP_SRC_8:
	break;
	case BPP_SRC_15:
	case BPP_SRC_16:
	src_width <<= 1;
	break;
	case BPP_SRC_24:
	src_width *= 3;
	break;
	case BPP_SRC_32:
	src_width <<= 2;
	break;
	}
	}
	dest_width *= s->cols;
	first = 0;
	/* TODO: Implement blanking. */
	if (!s->blank) {
	if (s->need_update && s->bpp <= BPP_SRC_8) {
	syborg_fb_update_palette(s);
	}
	framebuffer_update_display(s->ds,
	s->base, s->cols, s->rows,
	src_width, dest_width, 0,
	s->need_update,
	fn, s->palette,
	&first, &last);
	if (first >= 0) {
	dpy_update(s->ds, 0, first, s->cols, last - first + 1);
	}

	s->int_status \|= FB_INT_VSYNC;
	syborg_fb_update(s);
	}

	s->need_update = 0;
	}

	static void syborg_fb_invalidate_display(void * opaque)
	{
	SyborgFBState s = (SyborgFBState )opaque;
	s->need_update = 1;
	}

	static uint32_t syborg_fb_read(void *opaque, target_phys_addr_t offset)
	{
	SyborgFBState *s = opaque;

	DPRINTF("read reg %d\n", (int)offset);
	offset &= 0xfff;
	switch (offset >> 2) {
	case FB_ID:
	return SYBORG_ID_FRAMEBUFFER;

	case FB_BASE:
	return s->base;

	case FB_HEIGHT:
	return s->rows;

	case FB_WIDTH:
	return s->cols;

	case FB_ORIENTATION:
	return 0;

	case FB_BLANK:
	return s->blank;

	case FB_INT_MASK:
	return s->int_enable;

	case FB_INTERRUPT_CAUSE:
	return s->int_status;

	case FB_BPP:
	switch (s->bpp) {
	case BPP_SRC_1: return 1;
	case BPP_SRC_2: return 2;
	case BPP_SRC_4: return 4;
	case BPP_SRC_8: return 8;
	case BPP_SRC_15: return 15;
	case BPP_SRC_16: return 16;
	case BPP_SRC_24: return 24;
	case BPP_SRC_32: return 32;
	default: return 0;
	}

	case FB_COLOR_ORDER:
	return s->rgb;

	case FB_BYTE_ORDER:
	return s->endian;

	case FB_PIXEL_ORDER:
	return 0;

	case FB_ROW_PITCH:
	return s->pitch;

	case FB_ENABLED:
	return s->enabled;

	default:
	if ((offset >> 2) >= FB_PALETTE_START
	&& (offset >> 2) <= FB_PALETTE_END) {
	return s->raw_palette[(offset >> 2) - FB_PALETTE_START];
	} else {
	cpu_abort (cpu_single_env, "syborg_fb_read: Bad offset %x\n",
	(int)offset);
	}
	return 0;
	}
	}

	static void syborg_fb_write(void *opaque, target_phys_addr_t offset,
	uint32_t val)
	{
	SyborgFBState *s = opaque;

	DPRINTF("write reg %d = %d\n", (int)offset, val);
	s->need_update = 1;
	offset &= 0xfff;
	switch (offset >> 2) {
	case FB_BASE:
	s->base = val;
	s->need_int = 1;
	s->need_update = 1;
	syborg_fb_update(s);
	break;

	case FB_HEIGHT:
	s->rows = val;
	break;

	case FB_WIDTH:
	s->cols = val;
	break;

	case FB_ORIENTATION:
	/* TODO: Implement rotation. */
	break;

	case FB_BLANK:
	s->blank = val & 1;
	break;

	case FB_INT_MASK:
	s->int_enable = val;
	syborg_fb_update(s);
	break;

	case FB_INTERRUPT_CAUSE:
	s->int_status &= ~val;
	syborg_fb_update(s);
	break;

	case FB_BPP:
	switch (val) {
	case 1: val = BPP_SRC_1; break;
	case 2: val = BPP_SRC_2; break;
	case 4: val = BPP_SRC_4; break;
	case 8: val = BPP_SRC_8; break;
	/* case 15: val = BPP_SRC_15; break; */
	case 16: val = BPP_SRC_16; break;
	/* case 24: val = BPP_SRC_24; break; */
	case 32: val = BPP_SRC_32; break;
	default: val = s->bpp; break;
	}
	s->bpp = val;
	break;

	case FB_COLOR_ORDER:
	s->rgb = (val != 0);
	break;

	case FB_BYTE_ORDER:
	s->endian = (val != 0);
	break;

	case FB_PIXEL_ORDER:
	/* TODO: Implement this. */
	break;

	case FB_ROW_PITCH:
	s->pitch = val;
	break;

	case FB_ENABLED:
	s->enabled = val;
	break;

	default:
	if ((offset >> 2) >= FB_PALETTE_START
	&& (offset >> 2) <= FB_PALETTE_END) {
	s->raw_palette[(offset >> 2) - FB_PALETTE_START] = val;
	} else {
	cpu_abort (cpu_single_env, "syborg_fb_write: Bad offset %x\n",
	(int)offset);
	}
	break;
	}
	}

	static CPUReadMemoryFunc * const syborg_fb_readfn[] = {
	syborg_fb_read,
	syborg_fb_read,
	syborg_fb_read
	};

	static CPUWriteMemoryFunc * const syborg_fb_writefn[] = {
	syborg_fb_write,
	syborg_fb_write,
	syborg_fb_write
	};

	static void syborg_fb_save(QEMUFile f, void opaque)
	{
	SyborgFBState *s = opaque;
	int i;

	qemu_put_be32(f, s->need_int);
	qemu_put_be32(f, s->int_status);
	qemu_put_be32(f, s->int_enable);
	qemu_put_be32(f, s->enabled);
	qemu_put_be32(f, s->base);
	qemu_put_be32(f, s->pitch);
	qemu_put_be32(f, s->rows);
	qemu_put_be32(f, s->cols);
	qemu_put_be32(f, s->bpp);
	qemu_put_be32(f, s->rgb);
	for (i = 0; i < 256; i++) {
	qemu_put_be32(f, s->raw_palette[i]);
	}
	}

	static int syborg_fb_load(QEMUFile f, void opaque, int version_id)
	{
	SyborgFBState *s = opaque;
	int i;

	if (version_id != 1)
	return -EINVAL;

	s->need_int = qemu_get_be32(f);
	s->int_status = qemu_get_be32(f);
	s->int_enable = qemu_get_be32(f);
	s->enabled = qemu_get_be32(f);
	s->base = qemu_get_be32(f);
	s->pitch = qemu_get_be32(f);
	s->rows = qemu_get_be32(f);
	s->cols = qemu_get_be32(f);
	s->bpp = qemu_get_be32(f);
	s->rgb = qemu_get_be32(f);
	for (i = 0; i < 256; i++) {
	s->raw_palette[i] = qemu_get_be32(f);
	}
	s->need_update = 1;

	return 0;
	}

	static int syborg_fb_init(SysBusDevice *dev)
	{
	SyborgFBState *s = FROM_SYSBUS(SyborgFBState, dev);
	int iomemtype;

	sysbus_init_irq(dev, &s->irq);
	iomemtype = cpu_register_io_memory(syborg_fb_readfn,
	syborg_fb_writefn, s);
	sysbus_init_mmio(dev, 0x1000, iomemtype);

	s->ds = graphic_console_init(syborg_fb_update_display,
	syborg_fb_invalidate_display,
	NULL, NULL, s);

	if (s->cols != 0 && s->rows != 0) {
	qemu_console_resize(s->ds, s->cols, s->rows);
	}

	if (!s->cols)
	s->cols = ds_get_width(s->ds);
	if (!s->rows)
	s->rows = ds_get_height(s->ds);

	register_savevm(&dev->qdev, "syborg_framebuffer", -1, 1,
	syborg_fb_save, syborg_fb_load, s);
	return 0;
	}

	static SysBusDeviceInfo syborg_fb_info = {
	.init = syborg_fb_init,
	.qdev.name = "syborg,framebuffer",
	.qdev.size = sizeof(SyborgFBState),
	.qdev.props = (Property[]) {
	DEFINE_PROP_UINT32("width", SyborgFBState, cols, 0),
	DEFINE_PROP_UINT32("height", SyborgFBState, rows, 0),
	DEFINE_PROP_END_OF_LIST(),
	}
	};

	static void syborg_fb_register_devices(void)
	{
	sysbus_register_withprop(&syborg_fb_info);
	}

	device_init(syborg_fb_register_devices)