/////////////////////////////////////////////////////////////////////////
// $Id: svga_cirrus.cc,v 1.5 2004-11-06 17:03:43 vruppert Exp $
/////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2004 Makoto Suzuki (suzu)
//                    Volker Ruppert (vruppert)
//                    Robin Kay (komadori)
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//
//  This library 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
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
//
// limited PCI/ISA CLGD5446 support for Bochs
//
// there are still many unimplemented features:
//
// - 1bpp/4bpp
// - transparent compare not complete
// - some bitblt functions
// - ???
//
// some codes are copied from vga.cc and modified.
// some codes are ported from the cirrus emulation in qemu
//   (http://savannah.nongnu.org/projects/qemu).
//

#define BX_PLUGGABLE

#include "iodev.h"

#if BX_SUPPORT_CLGD54XX

// Only reference the array if the tile numbers are within the bounds
// of the array.  If out of bounds, do nothing.
#define SET_TILE_UPDATED(xtile,ytile,value)                              \
  do {                                                                   \
    if (((xtile) < BX_NUM_X_TILES) && ((ytile) < BX_NUM_Y_TILES))        \
      BX_CIRRUS_THIS s.vga_tile_updated[(xtile)][(ytile)] = value;          \
  } while (0)
// Only reference the array if the tile numbers are within the bounds
// of the array.  If out of bounds, return 1.
#define GET_TILE_UPDATED(xtile,ytile)                                    \
  ((((xtile) < BX_NUM_X_TILES) && ((ytile) < BX_NUM_Y_TILES))?           \
     BX_CIRRUS_THIS s.vga_tile_updated[(xtile)][(ytile)]                    \
     : 1)

#define LOG_THIS BX_CIRRUS_THIS

#if BX_USE_CIRRUS_SMF
#define VGA_READ(addr,len)       bx_vga_c::read_handler(theSvga,addr,len)
#define VGA_WRITE(addr,val,len)  bx_vga_c::write_handler(theSvga,addr,val,len)
#define SVGA_READ(addr,len)      svga_read_handler(theSvga,addr,len)
#define SVGA_WRITE(addr,val,len) svga_write_handler(theSvga,addr,val,len)
#else
#define VGA_READ(addr,len)       bx_vga_c::read(addr,len)
#define VGA_WRITE(addr,val,len)  bx_vga_c::write(addr,val,len)
#define SVGA_READ(addr,len)      svga_read(addr,len)
#define SVGA_WRITE(addr,val,len) svga_write(addr,val,len)
#endif // BX_USE_CIRRUS_SMF

#define ID_CLGD5428  (0x26<<2)
#define ID_CLGD5430  (0x28<<2)
#define ID_CLGD5434  (0x2A<<2)
#define ID_CLGD5446  (0x2E<<2)

// sequencer 0x07
#define CIRRUS_SR7_BPP_VGA            0x00
#define CIRRUS_SR7_BPP_SVGA           0x01
#define CIRRUS_SR7_BPP_MASK           0x0e
#define CIRRUS_SR7_BPP_8              0x00
#define CIRRUS_SR7_BPP_16_DOUBLEVCLK  0x02
#define CIRRUS_SR7_BPP_24             0x04
#define CIRRUS_SR7_BPP_16             0x06
#define CIRRUS_SR7_BPP_32             0x08
#define CIRRUS_SR7_ISAADDR_MASK       0xe0

// sequencer 0x0f
#define CIRRUS_MEMSIZE_512k        0x08
#define CIRRUS_MEMSIZE_1M          0x10
#define CIRRUS_MEMSIZE_2M          0x18
#define CIRRUS_MEMFLAGS_BANKSWITCH 0x80 // bank switching is enabled.

// sequencer 0x12
#define CIRRUS_CURSOR_SHOW         0x01
#define CIRRUS_CURSOR_HIDDENPEL    0x02
#define CIRRUS_CURSOR_LARGE        0x04 // 64x64 if set, 32x32 if clear

// sequencer 0x17
#define CIRRUS_BUSTYPE_VLBFAST   0x10
#define CIRRUS_BUSTYPE_PCI       0x20
#define CIRRUS_BUSTYPE_VLBSLOW   0x30
#define CIRRUS_BUSTYPE_ISA       0x38
#define CIRRUS_MMIO_ENABLE       0x04
#define CIRRUS_MMIO_USE_PCIADDR  0x40  // 0xb8000 if cleared.
#define CIRRUS_MEMSIZEEXT_DOUBLE 0x80

// control 0x0b
#define CIRRUS_BANKING_DUAL             0x01
#define CIRRUS_BANKING_GRANULARITY_16K  0x20  // set:16k, clear:4k

// control 0x30
#define CIRRUS_BLTMODE_BACKWARDS        0x01
#define CIRRUS_BLTMODE_MEMSYSDEST       0x02
#define CIRRUS_BLTMODE_MEMSYSSRC        0x04
#define CIRRUS_BLTMODE_TRANSPARENTCOMP  0x08
#define CIRRUS_BLTMODE_PATTERNCOPY      0x40
#define CIRRUS_BLTMODE_COLOREXPAND      0x80
#define CIRRUS_BLTMODE_PIXELWIDTHMASK   0x30
#define CIRRUS_BLTMODE_PIXELWIDTH8      0x00
#define CIRRUS_BLTMODE_PIXELWIDTH16     0x10
#define CIRRUS_BLTMODE_PIXELWIDTH24     0x20
#define CIRRUS_BLTMODE_PIXELWIDTH32     0x30

// control 0x31
#define CIRRUS_BLT_BUSY                 0x01
#define CIRRUS_BLT_START                0x02
#define CIRRUS_BLT_RESET                0x04
#define CIRRUS_BLT_FIFOUSED             0x10
#define CIRRUS_BLT_AUTOSTART            0x80

// control 0x32
#define CIRRUS_ROP_0                    0x00
#define CIRRUS_ROP_SRC_AND_DST          0x05
#define CIRRUS_ROP_NOP                  0x06
#define CIRRUS_ROP_SRC_AND_NOTDST       0x09
#define CIRRUS_ROP_NOTDST               0x0b
#define CIRRUS_ROP_SRC                  0x0d
#define CIRRUS_ROP_1                    0x0e
#define CIRRUS_ROP_NOTSRC_AND_DST       0x50
#define CIRRUS_ROP_SRC_XOR_DST          0x59
#define CIRRUS_ROP_SRC_OR_DST           0x6d
#define CIRRUS_ROP_NOTSRC_OR_NOTDST     0x90
#define CIRRUS_ROP_SRC_NOTXOR_DST       0x95
#define CIRRUS_ROP_SRC_OR_NOTDST        0xad
#define CIRRUS_ROP_NOTSRC               0xd0
#define CIRRUS_ROP_NOTSRC_OR_DST        0xd6
#define CIRRUS_ROP_NOTSRC_AND_NOTDST    0xda

// control 0x33
#define CIRRUS_BLTMODEEXT_SOLIDFILL        0x04
#define CIRRUS_BLTMODEEXT_COLOREXPINV      0x02
#define CIRRUS_BLTMODEEXT_DWORDGRANULARITY 0x01

#define CLGD543x_MMIO_BLTBGCOLOR    0x00 // dword
#define CLGD543x_MMIO_BLTFGCOLOR    0x04 // dword
#define CLGD543x_MMIO_BLTWIDTH      0x08 // word
#define CLGD543x_MMIO_BLTHEIGHT     0x0a // word
#define CLGD543x_MMIO_BLTDESTPITCH  0x0c // word
#define CLGD543x_MMIO_BLTSRCPITCH   0x0e // word
#define CLGD543x_MMIO_BLTDESTADDR   0x10 // dword
#define CLGD543x_MMIO_BLTSRCADDR    0x14 // dword
#define CLGD543x_MMIO_BLTWRITEMASK  0x17 // byte
#define CLGD543x_MMIO_BLTMODE       0x18 // byte
#define CLGD543x_MMIO_BLTROP        0x1a // byte
#define CLGD543x_MMIO_BLTMODEEXT    0x1b // byte
#define CLGD543x_MMIO_BLTTRANSPARENTCOLOR 0x1c // word?
#define CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK 0x20 // word?
#define CLGD543x_MMIO_BLTSTATUS     0x40 // byte

// PCI 0x00: vendor, 0x02: device
#define PCI_VENDOR_CIRRUS             0x1013
#define PCI_DEVICE_CLGD5430           0x00a0 // CLGD5430 or CLGD5440
#define PCI_DEVICE_CLGD5434           0x00a8
#define PCI_DEVICE_CLGD5436           0x00ac
#define PCI_DEVICE_CLGD5446           0x00b8
#define PCI_DEVICE_CLGD5462           0x00d0
#define PCI_DEVICE_CLGD5465           0x00d6
// PCI 0x04: command(word), 0x06(word): status
#define PCI_COMMAND_IOACCESS                0x0001
#define PCI_COMMAND_MEMACCESS               0x0002
#define PCI_COMMAND_BUSMASTER               0x0004
#define PCI_COMMAND_SPECIALCYCLE            0x0008
#define PCI_COMMAND_MEMWRITEINVALID         0x0010
#define PCI_COMMAND_PALETTESNOOPING         0x0020
#define PCI_COMMAND_PARITYDETECTION         0x0040
#define PCI_COMMAND_ADDRESSDATASTEPPING     0x0080
#define PCI_COMMAND_SERR                    0x0100
#define PCI_COMMAND_BACKTOBACKTRANS         0x0200
// PCI 0x08, 0xff000000 (0x09-0x0b:class,0x08:rev)
#define PCI_CLASS_BASE_DISPLAY        0x03
// PCI 0x08, 0x00ff0000
#define PCI_CLASS_SUB_VGA             0x00
// PCI 0x0c, 0x00ff0000 (0x0c:cacheline,0x0d:latency,0x0e:headertype,0x0f:Built-in self test)
#define PCI_CLASS_HEADERTYPE_00h  0x00
// 0x10-0x3f (headertype 00h)
// PCI 0x10,0x14,0x18,0x1c,0x20,0x24: base address mapping registers
//   0x10: MEMBASE, 0x14: IOBASE(hard-coded in XFree86 3.x)
#define PCI_MAP_MEM                 0x0
#define PCI_MAP_IO                  0x1
#define PCI_MAP_MEM_ADDR_MASK       (~0xf)
#define PCI_MAP_IO_ADDR_MASK        (~0x3)
#define PCI_MAP_MEMFLAGS_32BIT      0x0
#define PCI_MAP_MEMFLAGS_32BIT_1M   0x1
#define PCI_MAP_MEMFLAGS_64BIT      0x4
#define PCI_MAP_MEMFLAGS_CACHEABLE  0x8
// PCI 0x28: cardbus CIS pointer
// PCI 0x2c: subsystem vendor id, 0x2e: subsystem id
// PCI 0x30: expansion ROM base address
// PCI 0x34: 0xffffff00=reserved, 0x000000ff=capabilities pointer
// PCI 0x38: reserved
// PCI 0x3c: 0x3c=int-line, 0x3d=int-pin, 0x3e=min-gnt, 0x3f=maax-lat
// PCI 0x40-0xff: device dependent fields

// To implement the following stuffs, memory PnP is required!
// default PnP memory address (FIXME - can't relocate!)
#define CIRRUS_PNPMEM_BASE_ADDRESS  0xe0000000
#define CIRRUS_PNPMEM_SIZE          CIRRUS_VIDEO_MEMORY_BYTES
// default PnP memory-mapped I/O address (FIXME - can't relocate!)
#define CIRRUS_PNPMMIO_BASE_ADDRESS (CIRRUS_PNPMEM_BASE_ADDRESS + CIRRUS_PNPMEM_SIZE)
#define CIRRUS_PNPMMIO_SIZE         0x1000

#define BX_MAX(a,b) ((a) > (b) ? (a) : (b))
#define BX_MIN(a,b) ((a) < (b) ? (a) : (b))

static bx_svga_cirrus_c *theSvga = NULL;

  int
libvga_LTX_plugin_init(plugin_t *plugin, plugintype_t type, int argc, char *argv[])
{
  theSvga = new bx_svga_cirrus_c ();
  libvga_set_smf_pointer(theSvga);
  bx_devices.pluginVgaDevice = theSvga;
  BX_REGISTER_DEVICE_DEVMODEL(plugin, type, theSvga, BX_PLUGIN_VGA);
  return(0); // Success
}

  void
libvga_LTX_plugin_fini(void)
{
}


bx_svga_cirrus_c::bx_svga_cirrus_c(void) :
  bx_vga_c ()
{
  put("CLVGA");
  vidmem = NULL;
  tilemem = NULL;
}

bx_svga_cirrus_c::~bx_svga_cirrus_c()
{
  if (vidmem != NULL) {
    delete [] vidmem;
    }
  if (tilemem != NULL) {
    delete [] tilemem;
    }
}

  void
bx_svga_cirrus_c::init(void)
{
  // initialize VGA stuffs.
  BX_CIRRUS_THIS bx_vga_c::init();
  BX_CIRRUS_THIS bx_vga_c::init_iohandlers(
      svga_read_handler, svga_write_handler);
  BX_CIRRUS_THIS bx_vga_c::init_systemtimer(
      svga_timer_handler);

  // initialize SVGA stuffs.
#if BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI
  BX_CIRRUS_THIS pci_enabled = DEV_is_pci_device("cirrus");
#endif
  BX_CIRRUS_THIS svga_init_members();
#if BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI
  if (BX_CIRRUS_THIS pci_enabled) {
    BX_CIRRUS_THIS svga_init_pcihandlers();
  }
#endif
}

  void
bx_svga_cirrus_c::svga_init_members()
{
  unsigned i;

  // clear all registers.
  BX_CIRRUS_THIS sequencer.index = CIRRUS_SEQENCER_MAX + 1;
  for (i = 0; i <= CIRRUS_SEQENCER_MAX; i++)
    BX_CIRRUS_THIS sequencer.reg[i] = 0x00;
  BX_CIRRUS_THIS control.index = CIRRUS_CONTROL_MAX + 1;
  for (i = 0; i <= CIRRUS_CONTROL_MAX; i++)
    BX_CIRRUS_THIS control.reg[i] = 0x00;
  BX_CIRRUS_THIS control.shadow_reg0 = 0x00;
  BX_CIRRUS_THIS control.shadow_reg1 = 0x00;
  BX_CIRRUS_THIS crtc.index = CIRRUS_CRTC_MAX + 1;
  for (i = 0; i <= CIRRUS_CRTC_MAX; i++)
    BX_CIRRUS_THIS crtc.reg[i] = 0x00;
  BX_CIRRUS_THIS hidden_dac.lockindex = 0;
  BX_CIRRUS_THIS hidden_dac.data = 0x00;

  BX_CIRRUS_THIS svga_unlock_special = false;
  BX_CIRRUS_THIS svga_needs_update_tile = true;
  BX_CIRRUS_THIS svga_needs_update_dispentire = true;
  BX_CIRRUS_THIS svga_needs_update_mode = false;

  BX_CIRRUS_THIS svga_xres = 640;
  BX_CIRRUS_THIS svga_yres = 480;
  BX_CIRRUS_THIS svga_bpp = 8;
  BX_CIRRUS_THIS svga_pitch = 640;
  BX_CIRRUS_THIS bank_base[0] = 0;
  BX_CIRRUS_THIS bank_base[1] = 0;
  BX_CIRRUS_THIS bank_limit[0] = 0;
  BX_CIRRUS_THIS bank_limit[1] = 0;

  svga_reset_bitblt();

  BX_CIRRUS_THIS hw_cursor.x = 0;
  BX_CIRRUS_THIS hw_cursor.y = 0;
  BX_CIRRUS_THIS hw_cursor.size = 0;

  // memory allocation.
  BX_CIRRUS_THIS vidmem = new Bit8u[CIRRUS_VIDEO_MEMORY_BYTES];
  BX_CIRRUS_THIS tilemem = new Bit8u[X_TILESIZE * Y_TILESIZE * 4];

  // set some registers.

  BX_CIRRUS_THIS sequencer.reg[0x06] = 0x0f;
  BX_CIRRUS_THIS sequencer.reg[0x07] = 0x00; // 0xf0:linearbase(0x00 if disabled)
#if BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI
  if (BX_CIRRUS_THIS pci_enabled) {
    BX_CIRRUS_THIS crtc.reg[0x27] = ID_CLGD5446;
    BX_CIRRUS_THIS sequencer.reg[0x1F] = 0x2d; // MemClock
    BX_CIRRUS_THIS control.reg[0x18] = 0x0f;
    BX_CIRRUS_THIS sequencer.reg[0x0F] = 0x98;
    BX_CIRRUS_THIS sequencer.reg[0x17] = CIRRUS_BUSTYPE_PCI;
    BX_CIRRUS_THIS sequencer.reg[0x15] = 0x04; // memory size 4MB
    BX_CIRRUS_THIS memsize = (4 << 20);
  } else
#endif
  {
    BX_CIRRUS_THIS crtc.reg[0x27] = ID_CLGD5430;
    BX_CIRRUS_THIS sequencer.reg[0x1F] = 0x22; // MemClock
    BX_CIRRUS_THIS sequencer.reg[0x0F] = CIRRUS_MEMSIZE_2M;
    BX_CIRRUS_THIS sequencer.reg[0x17] = CIRRUS_BUSTYPE_ISA;
    BX_CIRRUS_THIS sequencer.reg[0x15] = 0x03; // memory size 2MB
    BX_CIRRUS_THIS memsize = (2 << 20);
  }

  BX_CIRRUS_THIS hidden_dac.lockindex = 5;
  BX_CIRRUS_THIS hidden_dac.data = 0;

  memset(BX_CIRRUS_THIS vidmem, 0xff, CIRRUS_VIDEO_MEMORY_BYTES);
  BX_CIRRUS_THIS disp_ptr = BX_CIRRUS_THIS vidmem;

#if BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI
  if (BX_CIRRUS_THIS pci_enabled) {
    // This should be done by the PCI BIOS
    WriteHostDWordToLittleEndian(
      &BX_CIRRUS_THIS pci_conf[0x10],
      (PCI_MAP_MEM | PCI_MAP_MEMFLAGS_32BIT | PCI_MAP_MEMFLAGS_CACHEABLE |
      CIRRUS_PNPMEM_BASE_ADDRESS));
    WriteHostDWordToLittleEndian(
      &BX_CIRRUS_THIS pci_conf[0x14],
      (PCI_MAP_MEM | PCI_MAP_MEMFLAGS_32BIT |
      CIRRUS_PNPMMIO_BASE_ADDRESS));
    DEV_pci_set_base_mem(BX_CIRRUS_THIS_PTR, cirrus_mem_read_handler,
                         cirrus_mem_write_handler,
                         &BX_CIRRUS_THIS pci_memaddr,
                         &BX_CIRRUS_THIS pci_conf[0x10],
                         CIRRUS_PNPMEM_SIZE);
    DEV_pci_set_base_mem(BX_CIRRUS_THIS_PTR, cirrus_mem_read_handler,
                         cirrus_mem_write_handler,
                         &BX_CIRRUS_THIS pci_mmioaddr,
                         &BX_CIRRUS_THIS pci_conf[0x14],
                         CIRRUS_PNPMMIO_SIZE);
  }
#endif
}

  void
bx_svga_cirrus_c::reset(unsigned type)
{
  // reset VGA stuffs.
  BX_CIRRUS_THIS bx_vga_c::reset(type);

  // reset SVGA stuffs.
  BX_CIRRUS_THIS svga_init_members();
}


  void
bx_svga_cirrus_c::redraw_area(unsigned x0, unsigned y0, 
                              unsigned width, unsigned height)
{
  unsigned xi, yi, x1, y1, xmax, ymax;

  if ((BX_CIRRUS_THIS sequencer.reg[0x07] & 0x01) == CIRRUS_SR7_BPP_VGA) {
    BX_CIRRUS_THIS bx_vga_c::redraw_area(x0,y0,width,height);
    return;
    }

  if (BX_CIRRUS_THIS svga_needs_update_mode) {
    return;
    }

  BX_CIRRUS_THIS svga_needs_update_tile = true;

  x1 = x0 + width  - 1;
  y1 = y0 + height - 1;
  xmax = BX_CIRRUS_THIS svga_xres;
  ymax = BX_CIRRUS_THIS svga_yres;
  for (yi=0; yi<ymax; yi+=Y_TILESIZE) {
    for (xi=0; xi<xmax; xi+=X_TILESIZE) {
      // is redraw rectangle outside x boundaries of this tile?
      if (x1 < xi) continue;
      if (x0 > (xi+X_TILESIZE-1)) continue;

      // is redraw rectangle outside y boundaries of this tile?
      if (y1 < yi) continue;
      if (y0 > (yi+Y_TILESIZE-1)) continue;

      unsigned xti = xi/X_TILESIZE;
      unsigned yti = yi/Y_TILESIZE;
      SET_TILE_UPDATED (xti, yti, 1);
      }
    }
}

  void
bx_svga_cirrus_c::mem_write_mode4and5_8bpp(Bit8u mode, Bit32u offset, Bit8u value)
{
  int x;
  Bit8u val = value;
  Bit8u *dst;

  dst = BX_CIRRUS_THIS vidmem + offset;
  for (x = 0; x < 8; x++) {
    if (val & 0x80) {
      *dst++ = BX_CIRRUS_THIS control.shadow_reg1;
    } else if (mode == 5) {
      *dst++ = BX_CIRRUS_THIS control.shadow_reg0;
    }
    val <<= 1;
  }
}

  void
bx_svga_cirrus_c::mem_write_mode4and5_16bpp(Bit8u mode, Bit32u offset, Bit8u value)
{
  int x;
  Bit8u val = value;
  Bit8u *dst;

  dst = BX_CIRRUS_THIS vidmem + offset;
  for (x = 0; x < 8; x++) {
    if (val & 0x80) {
      *dst++ = BX_CIRRUS_THIS control.shadow_reg1;
      *dst++ = BX_CIRRUS_THIS control.reg[0x11];
    } else if (mode == 5) {
      *dst++ = BX_CIRRUS_THIS control.shadow_reg0;
      *dst++ = BX_CIRRUS_THIS control.reg[0x10];
    }
    val <<= 1;
  }
}

#if BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI
  bx_bool
bx_svga_cirrus_c::cirrus_mem_read_handler(unsigned long addr, unsigned long len,
                                          void *data, void *param)
{
  Bit8u *data_ptr;

#ifdef BX_LITTLE_ENDIAN
  data_ptr = (Bit8u *) data;
#else // BX_BIG_ENDIAN
  data_ptr = (Bit8u *) data + (len - 1);
#endif
  for (unsigned i = 0; i < len; i++) {
    *data_ptr = BX_CIRRUS_THIS mem_read(addr);
    addr++;
#ifdef BX_LITTLE_ENDIAN
    data_ptr++;
#else // BX_BIG_ENDIAN
    data_ptr--;
#endif
  }
  return 1;
}
#endif

  Bit8u
bx_svga_cirrus_c::mem_read(Bit32u addr)
{
  if ((BX_CIRRUS_THIS sequencer.reg[0x07] & 0x01) == CIRRUS_SR7_BPP_VGA) {
    return BX_CIRRUS_THIS bx_vga_c::mem_read(addr);
    }

#if BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI
  if (BX_CIRRUS_THIS pci_enabled) {
    if ((addr >= BX_CIRRUS_THIS pci_memaddr) &&
        (addr < (BX_CIRRUS_THIS pci_memaddr + CIRRUS_PNPMEM_SIZE - 256))) {
      Bit8u *ptr;
      Bit32u offset;

      // video-to-cpu BLT
      if (BX_CIRRUS_THIS bitblt.memdst_needed != 0) {
        ptr = BX_CIRRUS_THIS bitblt.memdst_ptr;
        if (ptr != BX_CIRRUS_THIS bitblt.memdst_endptr) {
          BX_CIRRUS_THIS bitblt.memdst_ptr ++;
          return *ptr;
        }
        if (!svga_asyncbitblt_next()) {
          ptr = BX_CIRRUS_THIS bitblt.memdst_ptr;
          BX_CIRRUS_THIS bitblt.memdst_ptr ++;
          return *ptr;
        }
      }

      ptr = BX_CIRRUS_THIS vidmem;
      offset = addr - BX_CIRRUS_THIS pci_memaddr;
      if ((BX_CIRRUS_THIS control.reg[0x0b] & 0x14) == 0x14) {
        offset <<= 4;
      } else if (BX_CIRRUS_THIS control.reg[0x0b] & 0x02) {
        offset <<= 3;
      }
      return *(ptr + offset);
    } else if ((addr >= (BX_CIRRUS_THIS pci_memaddr + CIRRUS_PNPMEM_SIZE - 256)) &&
               (addr < (BX_CIRRUS_THIS pci_memaddr + CIRRUS_PNPMEM_SIZE))) {
      Bit32u offset = addr - (BX_CIRRUS_THIS pci_memaddr + CIRRUS_PNPMEM_SIZE - 256);
      return svga_mmio_blt_read(offset & 0xff);
    } else if ((addr >= BX_CIRRUS_THIS pci_mmioaddr) &&
      (addr < (BX_CIRRUS_THIS pci_mmioaddr + CIRRUS_PNPMMIO_SIZE))) {
      Bit32u offset;

      offset = addr - BX_CIRRUS_THIS pci_mmioaddr;
      if (offset >= 0x100) {
        return svga_mmio_blt_read(offset - 0x100);
      } else {
        return svga_mmio_vga_read(offset);
      }
    }
  }
#endif // BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI

  if (addr >= 0xA0000 && addr <= 0xAFFFF)
  {
    Bit32u bank;
    Bit32u offset;
    Bit8u *ptr;

    // video-to-cpu BLT
    if (BX_CIRRUS_THIS bitblt.memdst_needed != 0) {
      ptr = BX_CIRRUS_THIS bitblt.memdst_ptr;
      if (ptr != BX_CIRRUS_THIS bitblt.memdst_endptr) {
        BX_CIRRUS_THIS bitblt.memdst_ptr ++;
        return *ptr;
        }
      if (!svga_asyncbitblt_next()) {
        ptr = BX_CIRRUS_THIS bitblt.memdst_ptr;
        BX_CIRRUS_THIS bitblt.memdst_ptr ++;
        return *ptr;
        }
      }

    offset = addr & 0xffff;
    bank = (offset >> 15);
    offset &= 0x7fff;
    if (offset < bank_limit[bank]) {
      offset += bank_base[bank];
      if ((BX_CIRRUS_THIS control.reg[0x0b] & 0x14) == 0x14) {
        offset <<= 4;
      } else if (BX_CIRRUS_THIS control.reg[0x0b] & 0x02) {
        offset <<= 3;
      }
      offset &= (CIRRUS_VIDEO_MEMORY_BYTES - 1);
      return *(BX_CIRRUS_THIS vidmem + offset);
      }
    else {
      return 0xff;
      }
    }
  else if (addr >= 0xB8000 && addr <= 0xBFFFF) {
    // memory-mapped I/O.
    Bit32u offset;

    offset = addr - 0xb8000;
    if ((BX_CIRRUS_THIS sequencer.reg[0x17] & 0x44) == 0x04)
      return svga_mmio_blt_read(offset);
    }
  else {
    BX_ERROR(("mem_read 0x%08x",addr));
    }

  return 0xff;
}

#if BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI
  bx_bool
bx_svga_cirrus_c::cirrus_mem_write_handler(unsigned long addr, unsigned long len,
                                           void *data, void *param)
{
  Bit8u *data_ptr;

#ifdef BX_LITTLE_ENDIAN
  data_ptr = (Bit8u *) data;
#else // BX_BIG_ENDIAN
  data_ptr = (Bit8u *) data + (len - 1);
#endif
  for (unsigned i = 0; i < len; i++) {
    BX_CIRRUS_THIS mem_write(addr, *data_ptr);
    addr++;
#ifdef BX_LITTLE_ENDIAN
    data_ptr++;
#else // BX_BIG_ENDIAN
    data_ptr--;
#endif
  }
  return 1;
}
#endif

  void
bx_svga_cirrus_c::mem_write(Bit32u addr, Bit8u value)
{
  if ((BX_CIRRUS_THIS sequencer.reg[0x07] & 0x01) == CIRRUS_SR7_BPP_VGA) {
    BX_CIRRUS_THIS bx_vga_c::mem_write(addr,value);
    return;
    }

#if BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI
  if (BX_CIRRUS_THIS pci_enabled) {
    if ((addr >= BX_CIRRUS_THIS pci_memaddr) &&
        (addr < (BX_CIRRUS_THIS pci_memaddr + CIRRUS_PNPMEM_SIZE - 256))) {
      Bit32u offset;
      Bit8u mode;

      // cpu-to-video BLT
      if (BX_CIRRUS_THIS bitblt.memsrc_needed != 0) {
        *(BX_CIRRUS_THIS bitblt.memsrc_ptr)++ = (value);
        if (bitblt.memsrc_ptr == BX_CIRRUS_THIS bitblt.memsrc_endptr) {
          svga_asyncbitblt_next();
        }
        return;
      }

      offset = addr - BX_CIRRUS_THIS pci_memaddr;
      // BX_DEBUG(("write offset 0x%08x,value 0x%02x",offset,value));
      if ((BX_CIRRUS_THIS control.reg[0x0b] & 0x14) == 0x14) {
        offset <<= 4;
      } else if (BX_CIRRUS_THIS control.reg[0x0b] & 0x02) {
        offset <<= 3;
      }
      mode = BX_CIRRUS_THIS control.reg[0x05] & 0x07;
      if ((mode < 4) || (mode > 5) || ((BX_CIRRUS_THIS control.reg[0x0b] & 0x4) == 0)) {
        *(BX_CIRRUS_THIS vidmem + offset) = value;
      } else {
        if ((BX_CIRRUS_THIS control.reg[0x0b] & 0x14) != 0x14) {
          mem_write_mode4and5_8bpp(mode, offset, value);
        } else {
          mem_write_mode4and5_16bpp(mode, offset, value);
        }
      }
      BX_CIRRUS_THIS svga_needs_update_tile = true;
      SET_TILE_UPDATED(((offset % BX_CIRRUS_THIS svga_pitch) / (BX_CIRRUS_THIS svga_bpp / 8)) / X_TILESIZE,
                       (offset / BX_CIRRUS_THIS svga_pitch) / Y_TILESIZE, 1);
      return;
    } else if ((addr >= (BX_CIRRUS_THIS pci_memaddr + CIRRUS_PNPMEM_SIZE - 256)) &&
               (addr < (BX_CIRRUS_THIS pci_memaddr + CIRRUS_PNPMEM_SIZE))) {
      Bit32u offset = addr - (BX_CIRRUS_THIS pci_memaddr + CIRRUS_PNPMEM_SIZE - 256);
      svga_mmio_blt_write(offset & 0xff, value);
      return;
    } else if ((addr >= BX_CIRRUS_THIS pci_mmioaddr) &&
               (addr < (BX_CIRRUS_THIS pci_mmioaddr + CIRRUS_PNPMMIO_SIZE))) {
      // memory-mapped I/O.
      Bit32u offset;

      // BX_DEBUG(("write mmio 0x%08x",addr));
      offset = addr - BX_CIRRUS_THIS pci_mmioaddr;
      if (offset >= 0x100) {
        svga_mmio_blt_write(offset - 0x100, value);
      } else {
        svga_mmio_vga_write(offset,value);
      }
      return;
    }
  }
#endif // BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI

  if (addr >= 0xA0000 && addr <= 0xAFFFF) {
    Bit32u bank, offset;
    Bit8u mode;

    // cpu-to-video BLT
    if (BX_CIRRUS_THIS bitblt.memsrc_needed != 0) {
      *(BX_CIRRUS_THIS bitblt.memsrc_ptr)++ = (value);
      if (BX_CIRRUS_THIS bitblt.memsrc_ptr == BX_CIRRUS_THIS bitblt.memsrc_endptr) {
        svga_asyncbitblt_next();
        }
      return;
      }

    offset = addr & 0xffff;
    bank = (offset >> 15);
    offset &= 0x7fff;
    if (offset < bank_limit[bank]) {
      offset += bank_base[bank];
      if ((BX_CIRRUS_THIS control.reg[0x0b] & 0x14) == 0x14) {
        offset <<= 4;
      } else if (BX_CIRRUS_THIS control.reg[0x0b] & 0x02) {
        offset <<= 3;
      }
      offset &= (CIRRUS_VIDEO_MEMORY_BYTES - 1);
      mode = BX_CIRRUS_THIS control.reg[0x05] & 0x07;
      if ((mode < 4) || (mode > 5) || ((BX_CIRRUS_THIS control.reg[0x0b] & 0x4) == 0)) {
        *(BX_CIRRUS_THIS vidmem + offset) = value;
      } else {
        if ((BX_CIRRUS_THIS control.reg[0x0b] & 0x14) != 0x14) {
          mem_write_mode4and5_8bpp(mode, offset, value);
        } else {
          mem_write_mode4and5_16bpp(mode, offset, value);
        }
      }
      BX_CIRRUS_THIS svga_needs_update_tile = true;
      SET_TILE_UPDATED(((offset % BX_CIRRUS_THIS svga_pitch) / (BX_CIRRUS_THIS svga_bpp / 8)) / X_TILESIZE,
                       (offset / BX_CIRRUS_THIS svga_pitch) / Y_TILESIZE, 1);
    }
  } else if (addr >= 0xB8000 && addr <= 0xBFFFF) {
    // memory-mapped I/O.
    Bit32u offset;

    offset = addr - 0xb8000;
    if ((BX_CIRRUS_THIS sequencer.reg[0x17] & 0x44) == 0x04) {
      svga_mmio_blt_write(offset & 0xff, value);
      }
    }
  else {
    BX_ERROR(("mem_write 0x%08x, value 0x%02x",addr,value));
    }
}


  void
bx_svga_cirrus_c::get_text_snapshot(Bit8u **text_snapshot, 
                                    unsigned *txHeight, unsigned *txWidth)
{
  BX_CIRRUS_THIS bx_vga_c::get_text_snapshot(text_snapshot,txHeight,txWidth);
}

  void
bx_svga_cirrus_c::trigger_timer(void *this_ptr)
{
  BX_CIRRUS_THIS timer_handler(this_ptr);
}

  void
bx_svga_cirrus_c::set_update_interval (unsigned interval)
{
  BX_INFO (("Changing timer interval to %d", interval));
  BX_CIRRUS_THIS svga_timer_handler (theSvga);
  bx_pc_system.activate_timer (BX_CIRRUS_THIS timer_id, interval, 1);
}

  Bit8u
bx_svga_cirrus_c::get_actl_palette_idx(Bit8u index)
{
  return BX_CIRRUS_THIS bx_vga_c::get_actl_palette_idx(index);
}

  Bit32u
bx_svga_cirrus_c::svga_read_handler(void *this_ptr, Bit32u address, unsigned io_len)
{
#if !BX_USE_CIRRUS_SMF
  bx_svga_cirrus_c *class_ptr = (bx_svga_cirrus_c *) this_ptr;

  return( class_ptr->svga_read(address, io_len) );
}
  Bit32u
bx_svga_cirrus_c::svga_read(Bit32u address, unsigned io_len)
{
#else
  UNUSED(this_ptr);
#endif // !BX_USE_CIRRUS_SMF

  if ((io_len == 2) && ((address & 1) == 0)) {
    Bit32u value;
    value = (Bit32u)SVGA_READ(address,1);
    value |= (Bit32u)SVGA_READ(address+1,1) << 8;
    return value;
    }

  if (io_len != 1) {
    BX_PANIC(("SVGA read: io_len != 1"));
    }

  switch (address) {
    case 0x03b4: /* VGA: CRTC Index Register (monochrome emulation modes) */
    case 0x03d4: /* VGA: CRTC Index Register (color emulation modes) */
      return BX_CIRRUS_THIS crtc.index;
    case 0x03b5: /* VGA: CRTC Registers (monochrome emulation modes) */
    case 0x03d5: /* VGA: CRTC Registers (color emulation modes) */
      if (BX_CIRRUS_THIS is_unlocked())
        return BX_CIRRUS_THIS svga_read_crtc(address,BX_CIRRUS_THIS crtc.index);
      break;

    case 0x03c4: /* VGA: Sequencer Index Register */
      return BX_CIRRUS_THIS sequencer.index;
    case 0x03c5: /* VGA: Sequencer Registers */
      if ((BX_CIRRUS_THIS sequencer.index == 0x06) ||
          (BX_CIRRUS_THIS is_unlocked())) {
        return BX_CIRRUS_THIS svga_read_sequencer(address,BX_CIRRUS_THIS sequencer.index);
      }
      break;

    case 0x03c6: /* Hidden DAC */
      if (BX_CIRRUS_THIS is_unlocked()) {
        if ((++BX_CIRRUS_THIS hidden_dac.lockindex) == 5) {
          BX_CIRRUS_THIS hidden_dac.lockindex = 0;
          return BX_CIRRUS_THIS hidden_dac.data;
        }
      }
      break;
    case 0x03c8: /* PEL write address */
      BX_CIRRUS_THIS hidden_dac.lockindex = 0;
      break;
    case 0x03c9: /* PEL Data Register, hiddem pel colors 00..0F */
      if (BX_CIRRUS_THIS sequencer.reg[0x12] & CIRRUS_CURSOR_HIDDENPEL) {
        Bit8u index = (BX_CIRRUS_THIS s.pel.read_data_register & 0x0f) * 3 +
                      BX_CIRRUS_THIS s.pel.read_data_cycle;
        Bit8u retval = BX_CIRRUS_THIS hidden_dac.palette[index];
        BX_CIRRUS_THIS s.pel.read_data_cycle ++;
        if (BX_CIRRUS_THIS s.pel.read_data_cycle >= 3) {
          BX_CIRRUS_THIS s.pel.read_data_cycle = 0;
          BX_CIRRUS_THIS s.pel.read_data_register++;
        }
        return retval;
      }
      break;
    case 0x03ce: /* VGA: Graphics Controller Index Register */
      return BX_CIRRUS_THIS control.index;
    case 0x03cf: /* VGA: Graphics Controller Registers */
      if (BX_CIRRUS_THIS is_unlocked())
        return BX_CIRRUS_THIS svga_read_control(address,BX_CIRRUS_THIS control.index);
      break;

    default:
      break;
    }

  return VGA_READ(address,io_len);
}

  void
bx_svga_cirrus_c::svga_write_handler(void *this_ptr, Bit32u address, Bit32u value, unsigned io_len)
{
#if !BX_USE_CIRRUS_SMF
  bx_svga_cirrus_c *class_ptr = (bx_svga_cirrus_c *) this_ptr;

  class_ptr->svga_write(address, value, io_len);
}
  void
bx_svga_cirrus_c::svga_write(Bit32u address, Bit32u value, unsigned io_len)
{
#else
  UNUSED(this_ptr);
#endif // !BX_USE_CIRRUS_SMF

  if ((io_len == 2) && ((address & 1) == 0)) {
    SVGA_WRITE(address,value & 0xff,1);
    SVGA_WRITE(address+1,value >> 8,1);
    return;
    }

  if (io_len != 1) {
    BX_PANIC(("SVGA write: io_len != 1"));
    }

  switch (address) {
    case 0x03b4: /* VGA: CRTC Index Register (monochrome emulation modes) */
    case 0x03d4: /* VGA: CRTC Index Register (color emulation modes) */
      BX_CIRRUS_THIS crtc.index = value & 0x7f;
      break;
    case 0x03b5: /* VGA: CRTC Registers (monochrome emulation modes) */
    case 0x03d5: /* VGA: CRTC Registers (color emulation modes) */
      if (BX_CIRRUS_THIS is_unlocked()) {
        BX_CIRRUS_THIS svga_write_crtc(address,BX_CIRRUS_THIS crtc.index,value);
        return;
        }
      break;

    case 0x03c4: /* VGA: Sequencer Index Register */
      BX_CIRRUS_THIS sequencer.index = value;
      break;
    case 0x03c5: /* VGA: Sequencer Registers */
      if ((BX_CIRRUS_THIS sequencer.index == 0x06) ||
          (BX_CIRRUS_THIS is_unlocked())) {
        BX_CIRRUS_THIS svga_write_sequencer(address,BX_CIRRUS_THIS sequencer.index,value);
        return;
        }
      break;
    case 0x03c6: /* Hidden DAC */
      if (BX_CIRRUS_THIS is_unlocked()) {
        if (BX_CIRRUS_THIS hidden_dac.lockindex == 4) {
          BX_CIRRUS_THIS hidden_dac.data = value;
        }
        BX_CIRRUS_THIS hidden_dac.lockindex = 0;
        return;
      }
      break;
    case 0x03c9: /* PEL Data Register, hidden pel colors 00..0F */
      BX_CIRRUS_THIS svga_needs_update_dispentire = true;

      if (BX_CIRRUS_THIS sequencer.reg[0x12] & CIRRUS_CURSOR_HIDDENPEL) {
        Bit8u index = (BX_CIRRUS_THIS s.pel.write_data_register & 0x0f) * 3 +
                      BX_CIRRUS_THIS s.pel.write_data_cycle;
        BX_CIRRUS_THIS hidden_dac.palette[index] = value;
        BX_CIRRUS_THIS s.pel.write_data_cycle ++;
        if (BX_CIRRUS_THIS s.pel.write_data_cycle >= 3) {
          BX_CIRRUS_THIS s.pel.write_data_cycle = 0;
          BX_CIRRUS_THIS s.pel.write_data_register++;
        }
        return;
      }
      break;
    case 0x03ce: /* VGA: Graphics Controller Index Register */
      BX_CIRRUS_THIS control.index = value;
      break;
    case 0x03cf: /* VGA: Graphics Controller Registers */
      if (BX_CIRRUS_THIS is_unlocked()) {
        BX_CIRRUS_THIS svga_write_control(address,BX_CIRRUS_THIS control.index,value);
        return;
        }
      break;
    default:
      break;
    }

  VGA_WRITE(address,value,io_len);
}

  void
bx_svga_cirrus_c::svga_timer_handler(void *this_ptr)
{
#if !BX_USE_CIRRUS_SMF
  bx_svga_cirrus_c *class_ptr = (bx_svga_cirrus_c *) this_ptr;

  class_ptr->svga_timer();
}

  void
bx_svga_cirrus_c::svga_timer(void)
{
#else // !BX_USE_CIRRUS_SMF
  UNUSED(this_ptr);
#endif // !BX_USE_CIRRUS_SMF

  BX_CIRRUS_THIS svga_update();
  bx_gui->flush();
}

  void
bx_svga_cirrus_c::svga_modeupdate(void)
{
  Bit32u iTopOffset, iHeight;
  int width, iBpp, iDispBpp;

  iTopOffset = (BX_CIRRUS_THIS crtc.reg[0x0c] << 8)
       + BX_CIRRUS_THIS crtc.reg[0x0d]
       + ((BX_CIRRUS_THIS crtc.reg[0x1b] & 0x01) << 16)
       + ((BX_CIRRUS_THIS crtc.reg[0x1b] & 0x0c) << 15)
       + ((BX_CIRRUS_THIS crtc.reg[0x1d] & 0x80) << 12);
  iTopOffset <<= 2;

  iHeight = 1 + BX_CIRRUS_THIS crtc.reg[0x12]
       + ((BX_CIRRUS_THIS crtc.reg[0x07] & 0x02) << 7)
       + ((BX_CIRRUS_THIS crtc.reg[0x07] & 0x40) << 3);
  if ((BX_CIRRUS_THIS crtc.reg[0x1a] & 0x01) > 0) {
    iHeight <<= 1;
  }
  width = (BX_CIRRUS_THIS crtc.reg[0x01] + 1) * 8;
  iBpp = 8;
  iDispBpp = 4;
  if ((BX_CIRRUS_THIS sequencer.reg[0x07] & 0x1) == CIRRUS_SR7_BPP_SVGA) {
    switch (BX_CIRRUS_THIS sequencer.reg[0x07] & CIRRUS_SR7_BPP_MASK) {
    case CIRRUS_SR7_BPP_8:
      iBpp = 8;
      iDispBpp = 8;
      break;
    case CIRRUS_SR7_BPP_16_DOUBLEVCLK:
    case CIRRUS_SR7_BPP_16:
      iBpp = 16;
      iDispBpp = (BX_CIRRUS_THIS hidden_dac.data & 0x1) ? 16 : 15;
      break;
    case CIRRUS_SR7_BPP_24:
      iBpp = 24;
      iDispBpp = 24;
      break;
    case CIRRUS_SR7_BPP_32:
      iBpp = 32;
      iDispBpp = 32;
      break;
    default:
      BX_PANIC(("unknown bpp - seqencer.reg[0x07] = %02x",BX_CIRRUS_THIS sequencer.reg[0x07]));
      break;
    }
  }
  BX_INFO(("switched to %u x %u x %u",width,iHeight,iDispBpp));

  BX_CIRRUS_THIS svga_xres = width;
  BX_CIRRUS_THIS svga_yres = iHeight;
  BX_CIRRUS_THIS svga_bpp = iBpp;
  BX_CIRRUS_THIS svga_dispbpp = iDispBpp;
  BX_CIRRUS_THIS disp_ptr = BX_CIRRUS_THIS vidmem + iTopOffset;
}

  void
bx_svga_cirrus_c::draw_hardware_cursor(unsigned xc, unsigned yc, bx_svga_tileinfo_t *info)
{
  if (BX_CIRRUS_THIS hw_cursor.size &&
      (xc < BX_CIRRUS_THIS hw_cursor.x+BX_CIRRUS_THIS hw_cursor.size) &&
      (xc+X_TILESIZE > BX_CIRRUS_THIS hw_cursor.x) &&
      (yc < BX_CIRRUS_THIS hw_cursor.y+BX_CIRRUS_THIS hw_cursor.size) &&
      (yc+Y_TILESIZE > BX_CIRRUS_THIS hw_cursor.y)) {
    int i;
    unsigned w, h, pitch, cx, cy, cx0, cy0, cx1, cy1;

    Bit8u * tile_ptr, * tile_ptr2;
    Bit8u * plane0_ptr, *plane0_ptr2;
    Bit8u * plane1_ptr, *plane1_ptr2;
    unsigned long fgcol, bgcol;
    Bit64u plane0, plane1;

    cx0 = BX_CIRRUS_THIS hw_cursor.x > xc ? BX_CIRRUS_THIS hw_cursor.x : xc;
    cy0 = BX_CIRRUS_THIS hw_cursor.y > yc ? BX_CIRRUS_THIS hw_cursor.y : yc;
    cx1 = BX_CIRRUS_THIS hw_cursor.x+BX_CIRRUS_THIS hw_cursor.size < xc+X_TILESIZE ? BX_CIRRUS_THIS hw_cursor.x+BX_CIRRUS_THIS hw_cursor.size : xc+X_TILESIZE;
    cy1 = BX_CIRRUS_THIS hw_cursor.y+BX_CIRRUS_THIS hw_cursor.size < yc+Y_TILESIZE ? BX_CIRRUS_THIS hw_cursor.y+BX_CIRRUS_THIS hw_cursor.size : yc+Y_TILESIZE;

    tile_ptr = bx_gui->graphics_tile_get(xc, yc, &w, &h) +
               info->pitch * (cy0 - yc) + (info->bpp / 8) * (cx0 - xc);
    plane0_ptr = BX_CIRRUS_THIS vidmem + BX_CIRRUS_THIS memsize - 16384;

    switch (BX_CIRRUS_THIS hw_cursor.size) {
      case 32:
        plane0_ptr += (BX_CIRRUS_THIS sequencer.reg[0x13] & 0x3f) * 256;
        plane1_ptr = plane0_ptr + 128;
        pitch = 4;
        break;

      case 64:
        plane0_ptr += (BX_CIRRUS_THIS sequencer.reg[0x13] & 0x3c) * 256;
        plane1_ptr = plane0_ptr + 8;
        pitch = 16;
        break;

      default:
        BX_ERROR(("unsupported hardware cursor size"));
        return;
        break;
    }

    fgcol = MAKE_COLOUR(
      BX_CIRRUS_THIS hidden_dac.palette[45], 6, info->red_shift, info->red_mask,
      BX_CIRRUS_THIS hidden_dac.palette[46], 6, info->green_shift, info->green_mask,
      BX_CIRRUS_THIS hidden_dac.palette[47], 6, info->blue_shift, info->blue_mask);
    bgcol = MAKE_COLOUR(
      BX_CIRRUS_THIS hidden_dac.palette[0], 6, info->red_shift, info->red_mask,
      BX_CIRRUS_THIS hidden_dac.palette[1], 6, info->green_shift, info->green_mask,
      BX_CIRRUS_THIS hidden_dac.palette[2], 6, info->blue_shift, info->blue_mask);

    plane0_ptr += pitch * (cy0 - BX_CIRRUS_THIS hw_cursor.y);
    plane1_ptr += pitch * (cy0 - BX_CIRRUS_THIS hw_cursor.y);
    for (cy=cy0; cy<cy1; cy++) {
      tile_ptr2 = tile_ptr + (info->bpp/8) * (cx1 - cx0) - 1;
      plane0_ptr2 = plane0_ptr;
      plane1_ptr2 = plane1_ptr;
      plane0 = plane1 = 0;
      for (i=0; i<BX_CIRRUS_THIS hw_cursor.size; i+=8) {
        plane0 = (plane0 << 8) | *(plane0_ptr2++);
        plane1 = (plane1 << 8) | *(plane1_ptr2++);
      }
      plane0 >>= BX_CIRRUS_THIS hw_cursor.x+BX_CIRRUS_THIS hw_cursor.size - cx1;
      plane1 >>= BX_CIRRUS_THIS hw_cursor.x+BX_CIRRUS_THIS hw_cursor.size - cx1;
      for (cx=cx0; cx<cx1; cx++) {
        if (plane0 & 1) {
          if (plane1 & 1) {
            if (info->is_little_endian) {
              for (i=info->bpp-8; i>-8; i-=8) {
                *(tile_ptr2--) = fgcol >> i;
              }
            }
            else {
              for (i=0; i<info->bpp; i+=8) {
                *(tile_ptr2--) = fgcol >> i;
              }
            }
          }
          else {
            for (i=0; i<info->bpp; i+=8) {
              *(tile_ptr2--) ^= 0xff;
            }
          }
        }
        else {
          if (plane1 & 1) {
            if (info->is_little_endian) {
              for (i=info->bpp-8; i>-8; i-=8) {
                *(tile_ptr2--) = bgcol >> i;
              }
            }
            else {
              for (i=0; i<info->bpp; i+=8) {
                *(tile_ptr2--) = bgcol >> i;
              }
            }
          }
          else {
            tile_ptr2 -= (info->bpp/8);
          }
        }
        plane0 >>= 1;
        plane1 >>= 1;
      }
      tile_ptr += info->pitch;
      plane0_ptr += pitch;
      plane1_ptr += pitch;
    }
  }
}

  void
bx_svga_cirrus_c::svga_update(void)
{
  unsigned width, height, pitch;

  /* skip screen update when the sequencer is in reset mode or video is disabled */
  if (! BX_CIRRUS_THIS s.sequencer.reset1 ||
      ! BX_CIRRUS_THIS s.sequencer.reset2 ||
      ! BX_CIRRUS_THIS s.attribute_ctrl.video_enabled) {
    return;
  }

  if ((BX_CIRRUS_THIS sequencer.reg[0x07] & 0x01) == CIRRUS_SR7_BPP_VGA) {
    if (BX_CIRRUS_THIS svga_needs_update_mode) {
      BX_CIRRUS_THIS s.vga_mem_updated = 1;
      BX_CIRRUS_THIS svga_needs_update_mode = false;
    }
    BX_CIRRUS_THIS bx_vga_c::update();
    return;
  }
  else {
    if (BX_CIRRUS_THIS svga_needs_update_mode) {
      svga_modeupdate();
    }
  }

  width  = BX_CIRRUS_THIS svga_xres;
  height = BX_CIRRUS_THIS svga_yres;
  pitch = BX_CIRRUS_THIS svga_pitch;

  if (BX_CIRRUS_THIS svga_needs_update_mode) {
    width  = BX_CIRRUS_THIS svga_xres;
    height = BX_CIRRUS_THIS svga_yres;
    bx_gui->dimension_update(width, height, 0, 0, BX_CIRRUS_THIS svga_dispbpp);
    BX_CIRRUS_THIS svga_needs_update_mode = false;
    BX_CIRRUS_THIS svga_needs_update_dispentire = true;
  }

  if (BX_CIRRUS_THIS svga_needs_update_dispentire) {
    BX_CIRRUS_THIS redraw_area(0,0,width,height);
    BX_CIRRUS_THIS svga_needs_update_dispentire = false;
  }

  if (!BX_CIRRUS_THIS svga_needs_update_tile) {
    return;
  }
  BX_CIRRUS_THIS svga_needs_update_tile = false;

  unsigned xc, yc, xti, yti;
  unsigned r, c, w, h;
  int i;
  unsigned long red, green, blue, colour;
  Bit8u * vid_ptr, * vid_ptr2;
  Bit8u * tile_ptr, * tile_ptr2;
  bx_svga_tileinfo_t info;

  if (bx_gui->graphics_tile_info(&info)) {
    if (info.is_indexed) {
      switch (BX_CIRRUS_THIS svga_dispbpp) {
        case 4:
        case 15:
        case 16:
        case 24:
        case 32:
          BX_ERROR(("current guest pixel format is unsupported on indexed colour host displays"));
          break;
        case 8:
          for (yc=0, yti = 0; yc<height; yc+=Y_TILESIZE, yti++) {
            for (xc=0, xti = 0; xc<width; xc+=X_TILESIZE, xti++) {
              if (GET_TILE_UPDATED (xti, yti)) {
                vid_ptr = BX_CIRRUS_THIS disp_ptr + (yc * pitch + xc);
                tile_ptr = bx_gui->graphics_tile_get(xc, yc, &w, &h);
                for (r=0; r<h; r++) {
                  vid_ptr2  = vid_ptr;
                  tile_ptr2 = tile_ptr;
                  for (c=0; c<w; c++) {
                    colour = 0;
                    for (i=0; i<(int)BX_CIRRUS_THIS svga_bpp; i+=8) {
                      colour |= *(vid_ptr2++) << i;
                    }
                    if (info.is_little_endian) {
                      for (i=0; i<info.bpp; i+=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                    else {
                      for (i=info.bpp-8; i>-8; i-=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                  }
                  vid_ptr  += pitch;
                  tile_ptr += info.pitch;
                }
                // FIXME? hardware cursor unsupported
                bx_gui->graphics_tile_update_in_place(xc, yc, w, h);
                SET_TILE_UPDATED (xti, yti, 0);
              }
            }
          }
          break;
      }
    }
    else {
      switch (BX_CIRRUS_THIS svga_dispbpp) {
        case 4:
          BX_ERROR(("cannot draw 4bpp SVGA"));
          break;
        case 8:
          for (yc=0, yti = 0; yc<height; yc+=Y_TILESIZE, yti++) {
            for (xc=0, xti = 0; xc<width; xc+=X_TILESIZE, xti++) {
              if (GET_TILE_UPDATED (xti, yti)) {
                vid_ptr = BX_CIRRUS_THIS disp_ptr + (yc * pitch + xc);
                tile_ptr = bx_gui->graphics_tile_get(xc, yc, &w, &h);
                for (r=0; r<h; r++) {
                  vid_ptr2  = vid_ptr;
                  tile_ptr2 = tile_ptr;
                  for (c=0; c<w; c++) {
                    colour = *(vid_ptr2++);
                    colour = MAKE_COLOUR(
                      BX_CIRRUS_THIS s.pel.data[colour].red, 6, info.red_shift, info.red_mask,
                      BX_CIRRUS_THIS s.pel.data[colour].green, 6, info.green_shift, info.green_mask,
                      BX_CIRRUS_THIS s.pel.data[colour].blue, 6, info.blue_shift, info.blue_mask);
                    if (info.is_little_endian) {
                      for (i=0; i<info.bpp; i+=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                    else {
                      for (i=info.bpp-8; i>-8; i-=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                  }
                  vid_ptr  += pitch;
                  tile_ptr += info.pitch;
                }
                draw_hardware_cursor(xc, yc, &info);
                bx_gui->graphics_tile_update_in_place(xc, yc, w, h);
                SET_TILE_UPDATED (xti, yti, 0);
              }
            }
          }
          break;
        case 15:
          for (yc=0, yti = 0; yc<height; yc+=Y_TILESIZE, yti++) {
            for (xc=0, xti = 0; xc<width; xc+=X_TILESIZE, xti++) {
              if (GET_TILE_UPDATED (xti, yti)) {
                vid_ptr = BX_CIRRUS_THIS disp_ptr + (yc * pitch + (xc<<1));
                tile_ptr = bx_gui->graphics_tile_get(xc, yc, &w, &h);
                for (r=0; r<h; r++) {
                  vid_ptr2  = vid_ptr;
                  tile_ptr2 = tile_ptr;
                  for (c=0; c<w; c++) {
                    colour = *(vid_ptr2++);
                    colour |= *(vid_ptr2++) << 8;
                    colour = MAKE_COLOUR(
                      colour & 0x001f, 5, info.blue_shift, info.blue_mask,
                      colour & 0x03e0, 10, info.green_shift, info.green_mask,
                      colour & 0x7c00, 15, info.red_shift, info.red_mask);
                    if (info.is_little_endian) {
                      for (i=0; i<info.bpp; i+=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                    else {
                      for (i=info.bpp-8; i>-8; i-=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                  }
                  vid_ptr  += pitch;
                  tile_ptr += info.pitch; 
                }
                draw_hardware_cursor(xc, yc, &info);
                bx_gui->graphics_tile_update_in_place(xc, yc, w, h);
                SET_TILE_UPDATED (xti, yti, 0);
              }
            }
          }
          break;
        case 16:
          for (yc=0, yti = 0; yc<height; yc+=Y_TILESIZE, yti++) {
            for (xc=0, xti = 0; xc<width; xc+=X_TILESIZE, xti++) {
              if (GET_TILE_UPDATED (xti, yti)) {
                vid_ptr = BX_CIRRUS_THIS disp_ptr + (yc * pitch + (xc<<1));
                tile_ptr = bx_gui->graphics_tile_get(xc, yc, &w, &h);
                for (r=0; r<h; r++) {
                  vid_ptr2  = vid_ptr;
                  tile_ptr2 = tile_ptr;
                  for (c=0; c<w; c++) {
                    colour = *(vid_ptr2++);
                    colour |= *(vid_ptr2++) << 8;
                    colour = MAKE_COLOUR(
                      colour & 0x001f, 5, info.blue_shift, info.blue_mask,
                      colour & 0x07e0, 11, info.green_shift, info.green_mask,
                      colour & 0xf800, 16, info.red_shift, info.red_mask);
                    if (info.is_little_endian) {
                      for (i=0; i<info.bpp; i+=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                    else {
                      for (i=info.bpp-8; i>-8; i-=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                  }
                  vid_ptr  += pitch;
                  tile_ptr += info.pitch; 
                }
                draw_hardware_cursor(xc, yc, &info);
                bx_gui->graphics_tile_update_in_place(xc, yc, w, h);
                SET_TILE_UPDATED (xti, yti, 0);
              }
            }
          }
          break;
        case 24:
          for (yc=0, yti = 0; yc<height; yc+=Y_TILESIZE, yti++) {
            for (xc=0, xti = 0; xc<width; xc+=X_TILESIZE, xti++) {
              if (GET_TILE_UPDATED (xti, yti)) {
                vid_ptr = BX_CIRRUS_THIS disp_ptr + (yc * pitch + 3*xc);
                tile_ptr = bx_gui->graphics_tile_get(xc, yc, &w, &h);
                for (r=0; r<h; r++) {
                  vid_ptr2  = vid_ptr;
                  tile_ptr2 = tile_ptr;
                  for (c=0; c<w; c++) {
                    blue = *(vid_ptr2++);
                    green = *(vid_ptr2++);
                    red = *(vid_ptr2++);
                    colour = MAKE_COLOUR(
                      red, 8, info.red_shift, info.red_mask,
                      green, 8, info.green_shift, info.green_mask,
                      blue, 8, info.blue_shift, info.blue_mask);
                    if (info.is_little_endian) {
                      for (i=0; i<info.bpp; i+=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                    else {
                      for (i=info.bpp-8; i>-8; i-=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                  }
                  vid_ptr  += pitch;
                  tile_ptr += info.pitch; 
                }
                draw_hardware_cursor(xc, yc, &info);
                bx_gui->graphics_tile_update_in_place(xc, yc, w, h);
                SET_TILE_UPDATED (xti, yti, 0);
              }
            }
          }
          break;
        case 32:
          for (yc=0, yti = 0; yc<height; yc+=Y_TILESIZE, yti++) {
            for (xc=0, xti = 0; xc<width; xc+=X_TILESIZE, xti++) {
              if (GET_TILE_UPDATED (xti, yti)) {
                vid_ptr = BX_CIRRUS_THIS disp_ptr + (yc * pitch + (xc<<2));
                tile_ptr = bx_gui->graphics_tile_get(xc, yc, &w, &h);
                for (r=0; r<h; r++) {
                  vid_ptr2  = vid_ptr;
                  tile_ptr2 = tile_ptr;
                  for (c=0; c<w; c++) {
                    blue = *(vid_ptr2++);
                    green = *(vid_ptr2++);
                    red = *(vid_ptr2++);
                    vid_ptr2++;
                    colour = MAKE_COLOUR(
                      red, 8, info.red_shift, info.red_mask,
                      green, 8, info.green_shift, info.green_mask,
                      blue, 8, info.blue_shift, info.blue_mask);
                    if (info.is_little_endian) {
                      for (i=0; i<info.bpp; i+=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                    else {
                      for (i=info.bpp-8; i>-8; i-=8) {
                        *(tile_ptr2++) = colour >> i;
                      }
                    }
                  }
                  vid_ptr  += pitch;
                  tile_ptr += info.pitch;
                }
                draw_hardware_cursor(xc, yc, &info);
                bx_gui->graphics_tile_update_in_place(xc, yc, w, h);
                SET_TILE_UPDATED (xti, yti, 0);
              }
            }
          }
          break;
      }
    }
  }
  else {
    BX_PANIC(("cannot get svga tile info"));
  }
}

  void
bx_svga_cirrus_c::update_bank_ptr(Bit8u bank_index)
{
  unsigned offset;
  unsigned limit;

  if (BX_CIRRUS_THIS banking_is_dual())
    offset = BX_CIRRUS_THIS control.reg[0x09 + bank_index];
  else
    offset = BX_CIRRUS_THIS control.reg[0x09];

  if (BX_CIRRUS_THIS banking_granularity_is_16k())
    offset <<= 14;
  else
    offset <<= 12;

  if (CIRRUS_VIDEO_MEMORY_BYTES <= offset) {
    limit = 0;
    BX_ERROR(("bank offset %08x is invalid",offset));
  } else {
    limit = CIRRUS_VIDEO_MEMORY_BYTES - offset;
  }

  if (!BX_CIRRUS_THIS banking_is_dual() && (bank_index != 0)) {
    if (limit > 0x8000) {
      offset += 0x8000;
      limit -= 0x8000;
    } else {
      limit = 0;
    }
  }

  if (limit > 0) {
    BX_CIRRUS_THIS bank_base[bank_index] = offset;
    BX_CIRRUS_THIS bank_limit[bank_index] = limit;
  } else {
    BX_CIRRUS_THIS bank_base[bank_index] = 0;
    BX_CIRRUS_THIS bank_limit[bank_index] = 0;
  }
}

  Bit8u
bx_svga_cirrus_c::svga_read_crtc(Bit32u address, unsigned index)
{
  switch (index) {
    case 0x00: // VGA
    case 0x01: // VGA
    case 0x02: // VGA
    case 0x03: // VGA
    case 0x04: // VGA
    case 0x05: // VGA
    case 0x06: // VGA
    case 0x07: // VGA
    case 0x08: // VGA
    case 0x09: // VGA
    case 0x0a: // VGA
    case 0x0b: // VGA
    case 0x0c: // VGA
    case 0x0d: // VGA
    case 0x0e: // VGA
    case 0x0f: // VGA
    case 0x10: // VGA
    case 0x11: // VGA
    case 0x12: // VGA
    case 0x13: // VGA
    case 0x14: // VGA
    case 0x15: // VGA
    case 0x16: // VGA
    case 0x17: // VGA
    case 0x18: // VGA
      break;
    case 0x19:
    case 0x1A:
    case 0x1B:
    case 0x1C:
    case 0x1D:
    case 0x22:
    case 0x24:
    case 0x25:
    case 0x27:
      break;
    case 0x26:
      return (BX_CIRRUS_THIS s.attribute_ctrl.address & 0x3f);
    default:
      BX_ERROR(("CRTC index 0x%02x is unknown(read)", index));
      break;
    }

  if (index <= VGA_CRTC_MAX) {
    return VGA_READ(address,1);
    }

  if (index <= CIRRUS_CRTC_MAX) {
    return BX_CIRRUS_THIS crtc.reg[index];
    }

  return 0xff;
}

  void
bx_svga_cirrus_c::svga_write_crtc(Bit32u address, unsigned index, Bit8u value)
{
  BX_DEBUG(("crtc: index 0x%02x write 0x%02x", index, (unsigned)value));

  bx_bool update_pitch = 0;

  switch (index) {
    case 0x00: // VGA
    case 0x02: // VGA
    case 0x03: // VGA
    case 0x04: // VGA
    case 0x05: // VGA
    case 0x06: // VGA
    case 0x08: // VGA
    case 0x0a: // VGA
    case 0x0b: // VGA
    case 0x0e: // VGA
    case 0x0f: // VGA
    case 0x10: // VGA
    case 0x11: // VGA
    case 0x14: // VGA
    case 0x15: // VGA
    case 0x16: // VGA
    case 0x17: // VGA
    case 0x18: // VGA
      break;

    case 0x01: // VGA
    case 0x07: // VGA
    case 0x09: // VGA
    case 0x0c: // VGA (display offset 0x00ff00)
    case 0x0d: // VGA (display offset 0x0000ff)
    case 0x12: // VGA
    case 0x1A: // 0x01: interlaced video mode
    case 0x1D: // 0x80: offset 0x080000 (>=CLGD5434)
      BX_CIRRUS_THIS svga_needs_update_mode = true;
      break;

    case 0x13: // VGA
    case 0x1B: // 0x01: offset 0x010000, 0x0c: offset 0x060000
      update_pitch = 1;
      break;

    case 0x19:
    case 0x1C:
      break;

    default:
      BX_ERROR(("CRTC index 0x%02x is unknown(write 0x%02x)", index, (unsigned)value));
      return;
    }

  if (index <= CIRRUS_CRTC_MAX) {
    BX_CIRRUS_THIS crtc.reg[index] = value;
  }
  if (index <= VGA_CRTC_MAX) {
    VGA_WRITE(address,value,1);
  }

  if (update_pitch) {
    BX_CIRRUS_THIS svga_pitch = (BX_CIRRUS_THIS crtc.reg[0x13] << 3) | ((BX_CIRRUS_THIS crtc.reg[0x1b] & 0x10) << 7);
    BX_CIRRUS_THIS svga_needs_update_mode = true;
  }
}

  Bit8u
bx_svga_cirrus_c::svga_read_sequencer(Bit32u address, unsigned index)
{
  switch (index) {
    case 0x00:  // VGA
    case 0x01:  // VGA
    case 0x02:  // VGA
    case 0x03:  // VGA
    case 0x04:  // VGA
      break;
    case 0x6: // cirrus unlock extensions
    case 0x7: // cirrus extended sequencer mode
    case 0xf: // cirrus dram control
    case 0x12: // graphics cursor attribute
    case 0x13: // graphics cursor pattern address offset
    case 0x17: // configuration readback & extended control
      break;
    case 0x10: // cursor xpos << 5 (index & 0x3f)
    case 0x30:
    case 0x50:
    case 0x70:
    case 0x90:
    case 0xb0:
    case 0xd0:
    case 0xf0:
      return BX_CIRRUS_THIS sequencer.reg[0x10];
    case 0x11: // cursor ypos << 5 (index & 0x3f)
    case 0x31:
    case 0x51:
    case 0x71:
    case 0x91:
    case 0xb1:
    case 0xd1:
    case 0xf1:
      return BX_CIRRUS_THIS sequencer.reg[0x11];
    default:
      BX_INFO (("sequencer index 0x%02x is unknown(read)", index));
      break;
    }

  if (index <= VGA_SEQENCER_MAX) {
    return VGA_READ(address,1);
  }

  if (index <= CIRRUS_SEQENCER_MAX) {
    return BX_CIRRUS_THIS sequencer.reg[index];
  }

  return 0xff;
}

  void
bx_svga_cirrus_c::svga_write_sequencer(Bit32u address, unsigned index, Bit8u value)
{
  BX_DEBUG(("sequencer: index 0x%02x write 0x%02x", index, (unsigned)value));

  bx_bool update_cursor = 0;
  Bit16u x, y, size;

  x = BX_CIRRUS_THIS hw_cursor.x;
  y = BX_CIRRUS_THIS hw_cursor.y;
  size = BX_CIRRUS_THIS hw_cursor.size;

  switch (index) {
    case 0x00:  // VGA
    case 0x02:  // VGA
    case 0x03:  // VGA
      break;
    case 0x01:  // VGA
    case 0x04:  // VGA
      BX_CIRRUS_THIS svga_needs_update_mode = true;
      break;
    case 0x6: // cirrus unlock extensions
      value &= 0x17;
      if (value == 0x12) {
        BX_CIRRUS_THIS svga_unlock_special = true;
        BX_CIRRUS_THIS sequencer.reg[0x6] = 0x12;
        }
      else {
        BX_CIRRUS_THIS svga_unlock_special = false;
        BX_CIRRUS_THIS sequencer.reg[0x6] = 0x0f;
        }
      return;
    case 0x7: // cirrus extended sequencer mode
      if (value != BX_CIRRUS_THIS sequencer.reg[0x7]) {
        BX_CIRRUS_THIS svga_needs_update_mode = true;
      }
      break;
    case 0x08:
    case 0x09:
    case 0x0a:  // cirrus scratch reg 1
    case 0x0b:
    case 0x0c:
    case 0x0d:
    case 0x0e:
    case 0x1b:
    case 0x1c:
    case 0x1d:
    case 0x1e:
      break;
    case 0x0f:
      return;
    case 0x10: // cursor xpos << 5 (index & 0x3f)
    case 0x30:
    case 0x50:
    case 0x70:
    case 0x90:
    case 0xb0:
    case 0xd0:
    case 0xf0:
      BX_CIRRUS_THIS sequencer.reg[0x10] = value;
      x = BX_CIRRUS_THIS hw_cursor.x;
      BX_CIRRUS_THIS hw_cursor.x = (value << 3) | (index >> 5);
      update_cursor = 1;
      break;
    case 0x11: // cursor ypos << 5 (index & 0x3f)
    case 0x31:
    case 0x51:
    case 0x71:
    case 0x91:
    case 0xb1:
    case 0xd1:
    case 0xf1:
      BX_CIRRUS_THIS sequencer.reg[0x11] = value;
      y = BX_CIRRUS_THIS hw_cursor.y;
      BX_CIRRUS_THIS hw_cursor.y = (value << 3) | (index >> 5);
      update_cursor = 1;
      break;
    case 0x12:
      size = BX_CIRRUS_THIS hw_cursor.size;
      if (value & CIRRUS_CURSOR_SHOW) {
        if (value & CIRRUS_CURSOR_LARGE) {
          BX_CIRRUS_THIS hw_cursor.size = 64;
        }
        else {
         BX_CIRRUS_THIS hw_cursor.size = 32;
        }
      }
      else {
        BX_CIRRUS_THIS hw_cursor.size = 0;
      }
      update_cursor = 1;
      break;
    case 0x13:
      update_cursor = 1;
      break;
    case 0x17:
      value = (BX_CIRRUS_THIS sequencer.reg[0x17] & 0x38) | (value & 0xc7);
      break;
    default:
      BX_INFO (("sequencer index 0x%02x is unknown(write 0x%02x)", index, (unsigned)value));
      break;
    }

  if (update_cursor) {
    BX_CIRRUS_THIS redraw_area(x, y, size, size);
    BX_CIRRUS_THIS redraw_area(BX_CIRRUS_THIS hw_cursor.x, BX_CIRRUS_THIS hw_cursor.y, BX_CIRRUS_THIS hw_cursor.size, BX_CIRRUS_THIS hw_cursor.size);
  }

  if (index <= CIRRUS_SEQENCER_MAX) {
    BX_CIRRUS_THIS sequencer.reg[index] = value;
    }
  if (index <= VGA_SEQENCER_MAX) {
    VGA_WRITE(address,value,1);
    }
}

  Bit8u
bx_svga_cirrus_c::svga_read_control(Bit32u address, unsigned index)
{
  switch (index) {
    case 0x00:  // VGA
      return BX_CIRRUS_THIS control.shadow_reg0;
    case 0x01:  // VGA
      return BX_CIRRUS_THIS control.shadow_reg1;
    case 0x05:  // VGA
      return BX_CIRRUS_THIS control.reg[index];
    case 0x02:  // VGA
    case 0x03:  // VGA
    case 0x04:  // VGA
    case 0x06:  // VGA
    case 0x07:  // VGA
    case 0x08:  // VGA
      break;
    case 0x09: // bank offset #0
    case 0x0A: // bank offset #1
    case 0x0B:
      break;

    case 0x10:  // BGCOLOR 0x0000ff00
    case 0x11:  // FGCOLOR 0x0000ff00
    case 0x12:  // BGCOLOR 0x00ff0000
    case 0x13:  // FGCOLOR 0x00ff0000
    case 0x14:  // BGCOLOR 0xff000000
    case 0x15:  // FGCOLOR 0xff000000
      break;

    case 0x20: // BLT WIDTH 0x0000ff
    case 0x21: // BLT WIDTH 0x001f00
    case 0x22: // BLT HEIGHT 0x0000ff
    case 0x23: // BLT HEIGHT 0x001f00
    case 0x24: // BLT DEST PITCH 0x0000ff
    case 0x25: // BLT DEST PITCH 0x001f00
    case 0x26: // BLT SRC PITCH 0x0000ff
    case 0x27: // BLT SRC PITCH 0x001f00
    case 0x28: // BLT DEST ADDR 0x0000ff
    case 0x29: // BLT DEST ADDR 0x00ff00
    case 0x2a: // BLT DEST ADDR 0x3f0000
    case 0x2c: // BLT SRC ADDR 0x0000ff
    case 0x2d: // BLT SRC ADDR 0x00ff00
    case 0x2e: // BLT SRC ADDR 0x3f0000
    case 0x2f: // BLT WRITE MASK
    case 0x30: // BLT MODE
    case 0x31: // BLT STATUS
    case 0x32: // RASTER OP
    case 0x33: // BLT MODE EXTENSION
    case 0x34: // BLT TRANSPARENT COLOR 0x00ff
    case 0x35: // BLT TRANSPARENT COLOR 0xff00
    case 0x38: // BLT TRANSPARENT COLOR MASK 0x00ff
    case 0x39: // BLT TRANSPARENT COLOR MASK 0xff00
      break;

    default:
      BX_INFO (("control index 0x%02x is unknown(read)", index));
      break;
    }

  if (index <= VGA_CONTROL_MAX) {
    return VGA_READ(address,1);
  }

  if (index <= CIRRUS_CONTROL_MAX) {
    return BX_CIRRUS_THIS control.reg[index];
  }

  return 0xff;
}

  void
bx_svga_cirrus_c::svga_write_control(Bit32u address, unsigned index, Bit8u value)
{
  Bit8u old_value;

  BX_DEBUG(("control: index 0x%02x write 0x%02x", index, (unsigned)value));

  switch (index) {
    case 0x00:  // VGA
      BX_CIRRUS_THIS control.shadow_reg0 = value;
      break;
    case 0x01:  // VGA
      BX_CIRRUS_THIS control.shadow_reg1 = value;
      break;
    case 0x02:  // VGA
    case 0x03:  // VGA
    case 0x04:  // VGA
    case 0x07:  // VGA
    case 0x08:  // VGA
      break;
    case 0x05:  // VGA
    case 0x06:  // VGA
      BX_CIRRUS_THIS svga_needs_update_mode = true;
      break;
    case 0x09: // bank offset #0
    case 0x0A: // bank offset #1
    case 0x0B:
      BX_CIRRUS_THIS control.reg[index] = value;
      update_bank_ptr(0);
      update_bank_ptr(1);
      break;

    case 0x10:  // BGCOLOR 0x0000ff00
    case 0x11:  // FGCOLOR 0x0000ff00
    case 0x12:  // BGCOLOR 0x00ff0000
    case 0x13:  // FGCOLOR 0x00ff0000
    case 0x14:  // BGCOLOR 0xff000000
    case 0x15:  // FGCOLOR 0xff000000
      break;

    case 0x20: // BLT WIDTH 0x0000ff
      break;
    case 0x21: // BLT WIDTH 0x001f00
      value &= 0x1f;
      break;
    case 0x22: // BLT HEIGHT 0x0000ff
      break;
    case 0x23: // BLT HEIGHT 0x001f00
      value &= 0x1f;
      break;
    case 0x24: // BLT DEST PITCH 0x0000ff
      break;
    case 0x25: // BLT DEST PITCH 0x001f00
      value &= 0x1f;
      break;
    case 0x26: // BLT SRC PITCH 0x0000ff
      break;
    case 0x27: // BLT SRC PITCH 0x001f00
      value &= 0x1f;
      break;
    case 0x28: // BLT DEST ADDR 0x0000ff
      break;
    case 0x29: // BLT DEST ADDR 0x00ff00
      break;
    case 0x2a: // BLT DEST ADDR 0x3f0000
      BX_CIRRUS_THIS control.reg[index] = value & 0x3f;
      if (BX_CIRRUS_THIS control.reg[0x31] & CIRRUS_BLT_AUTOSTART) {
        svga_bitblt();
      }
      return;
    case 0x2c: // BLT SRC ADDR 0x0000ff
      break;
    case 0x2d: // BLT SRC ADDR 0x00ff00
      break;
    case 0x2e: // BLT SRC ADDR 0x3f0000
      value &= 0x3f;
      break;
    case 0x2f: // BLT WRITE MASK
      if (value & 0x80) {
        BX_ERROR(("BLT WRITE MASK support is not complete (value = 0x%02x)", value));
      }
      break;
    case 0x30: // BLT MODE
      break;
    case 0x31: // BLT STATUS/START
      old_value = BX_CIRRUS_THIS control.reg[0x31];
      BX_CIRRUS_THIS control.reg[0x31] = value;
      if (((old_value & CIRRUS_BLT_RESET) != 0) &&
          ((value & CIRRUS_BLT_RESET) == 0)) {
        svga_reset_bitblt();
        }
      else if (((old_value & CIRRUS_BLT_START) == 0) &&
          ((value & CIRRUS_BLT_START) != 0)) {
        BX_CIRRUS_THIS control.reg[0x31] |= CIRRUS_BLT_BUSY;
        svga_bitblt();
        }
      return;
    case 0x32: // RASTER OP
    case 0x33: // BLT MODE EXTENSION
      break;
    case 0x34: // BLT TRANSPARENT COLOR 0x00ff
    case 0x35: // BLT TRANSPARENT COLOR 0xff00
    case 0x38: // BLT TRANSPARENT COLOR MASK 0x00ff
    case 0x39: // BLT TRANSPARENT COLOR MASK 0xff00
    default:
      BX_INFO (("control index 0x%02x is unknown(write 0x%02x)", index, (unsigned)value));
      break;
    }

  if (index <= CIRRUS_CONTROL_MAX) {
    BX_CIRRUS_THIS control.reg[index] = value;
  }
  if (index <= VGA_CONTROL_MAX) {
    VGA_WRITE(address,value,1);
  }
}

  Bit8u
bx_svga_cirrus_c::svga_mmio_vga_read(Bit32u address)
{
  Bit8u value = 0xff;
//  bx_bool svga_unlock_special_old = BX_CIRRUS_THIS svga_unlock_special;

  BX_DEBUG(("MMIO vga read - address 0x%04x, value 0x%02x",address,value));

//  BX_CIRRUS_THIS svga_unlock_special = true;

#if BX_USE_CIRRUS_SMF
  value = (Bit8u)svga_read_handler(theSvga,0x3c0+address,1);
#else // BX_USE_CIRRUS_SMF
  value = (Bit8u)svga_read(0x3c0+address,1);
#endif // BX_USE_CIRRUS_SMF

//  BX_CIRRUS_THIS svga_unlock_special = svga_unlock_special_old;
  return value;
}

  void
bx_svga_cirrus_c::svga_mmio_vga_write(Bit32u address,Bit8u value)
{
//  bx_bool svga_unlock_special_old = BX_CIRRUS_THIS svga_unlock_special;

  BX_DEBUG(("MMIO vga write - address 0x%04x, value 0x%02x",address,value));

//  BX_CIRRUS_THIS svga_unlock_special = true;

#if BX_USE_CIRRUS_SMF
  svga_write_handler(theSvga,0x3c0+address,value,1);
#else // BX_USE_CIRRUS_SMF
  svga_write(0x3c0+address,value,1);
#endif // BX_USE_CIRRUS_SMF

/*  switch (BX_CIRRUS_THIS sequencer.reg[0x06]) {
    case 0x0f:
      svga_unlock_special_old = false;
      break;
    case 0x12:
      svga_unlock_special_old = true;
      break;
    }

  BX_CIRRUS_THIS svga_unlock_special = svga_unlock_special_old;*/
}

  Bit8u
bx_svga_cirrus_c::svga_mmio_blt_read(Bit32u address)
{
  Bit8u value = 0xff;

  switch (address) {
    case (CLGD543x_MMIO_BLTBGCOLOR+0):
      value = BX_CIRRUS_THIS control.shadow_reg0;
      break;
    case (CLGD543x_MMIO_BLTBGCOLOR+1):
      value = svga_read_control(0x3cf,0x10);
      break;
    case (CLGD543x_MMIO_BLTBGCOLOR+2):
      value = svga_read_control(0x3cf,0x12);
      break;
    case (CLGD543x_MMIO_BLTBGCOLOR+3):
      value = svga_read_control(0x3cf,0x14);
      break;
    case (CLGD543x_MMIO_BLTFGCOLOR+0):
      value = BX_CIRRUS_THIS control.shadow_reg1;
      break;
    case (CLGD543x_MMIO_BLTFGCOLOR+1):
      value = svga_read_control(0x3cf,0x11);
      break;
    case (CLGD543x_MMIO_BLTFGCOLOR+2):
      value = svga_read_control(0x3cf,0x13);
      break;
    case (CLGD543x_MMIO_BLTFGCOLOR+3):
      value = svga_read_control(0x3cf,0x15);
      break;
    case (CLGD543x_MMIO_BLTWIDTH+0):
      value = svga_read_control(0x3cf,0x20);
      break;
    case (CLGD543x_MMIO_BLTWIDTH+1):
      value = svga_read_control(0x3cf,0x21);
      break;
    case (CLGD543x_MMIO_BLTHEIGHT+0):
      value = svga_read_control(0x3cf,0x22);
      break;
    case (CLGD543x_MMIO_BLTHEIGHT+1):
      value = svga_read_control(0x3cf,0x23);
      break;
    case (CLGD543x_MMIO_BLTDESTPITCH+0):
      value = svga_read_control(0x3cf,0x24);
      break;
    case (CLGD543x_MMIO_BLTDESTPITCH+1):
      value = svga_read_control(0x3cf,0x25);
      break;
    case (CLGD543x_MMIO_BLTSRCPITCH+0):
      value = svga_read_control(0x3cf,0x26);
      break;
    case (CLGD543x_MMIO_BLTSRCPITCH+1):
      value = svga_read_control(0x3cf,0x27);
      break;
    case (CLGD543x_MMIO_BLTDESTADDR+0):
      value = svga_read_control(0x3cf,0x28);
      break;
    case (CLGD543x_MMIO_BLTDESTADDR+1):
      value = svga_read_control(0x3cf,0x29);
      break;
    case (CLGD543x_MMIO_BLTDESTADDR+2):
      value = svga_read_control(0x3cf,0x2a);
      break;
    case (CLGD543x_MMIO_BLTDESTADDR+3):
      value = svga_read_control(0x3cf,0x2b);
      break;
    case (CLGD543x_MMIO_BLTSRCADDR+0):
      value = svga_read_control(0x3cf,0x2c);
      break;
    case (CLGD543x_MMIO_BLTSRCADDR+1):
      value = svga_read_control(0x3cf,0x2d);
      break;
    case (CLGD543x_MMIO_BLTSRCADDR+2):
      value = svga_read_control(0x3cf,0x2e);
      break;
    case CLGD543x_MMIO_BLTWRITEMASK:
      value = svga_read_control(0x3cf,0x2f);
      break;
    case CLGD543x_MMIO_BLTMODE:
      value = svga_read_control(0x3cf,0x30);
      break;
    case CLGD543x_MMIO_BLTROP:
      value = svga_read_control(0x3cf,0x32);
      break;
    case CLGD543x_MMIO_BLTMODEEXT:
      value = svga_read_control(0x3cf,0x33);
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLOR+0):
      value = svga_read_control(0x3cf,0x34);
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLOR+1):
      value = svga_read_control(0x3cf,0x35);
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLOR+2):
      BX_ERROR(("CLGD543x_MMIO_BLTTRANSPARENTCOLOR"));
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLOR+3):
      BX_ERROR(("CLGD543x_MMIO_BLTTRANSPARENTCOLOR"));
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK+0):
      value = svga_read_control(0x3cf,0x38);
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK+1):
      value = svga_read_control(0x3cf,0x39);
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK+2):
      BX_ERROR(("CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK"));
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK+3):
      BX_ERROR(("CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK"));
      break;
    case CLGD543x_MMIO_BLTSTATUS:
      value = svga_read_control(0x3cf,0x31);
      break;
    default:
      BX_ERROR(("MMIO blt read - address 0x%04x",address));
      break;
    }

  BX_DEBUG(("MMIO blt read - address 0x%04x, value 0x%02x",address,value));

  return value;
}

  void
bx_svga_cirrus_c::svga_mmio_blt_write(Bit32u address,Bit8u value)
{
  BX_DEBUG(("MMIO blt write - address 0x%04x, value 0x%02x",address,value));

  switch (address) {
    case (CLGD543x_MMIO_BLTBGCOLOR+0):
      BX_CIRRUS_THIS control.shadow_reg0 = value;
      break;
    case (CLGD543x_MMIO_BLTBGCOLOR+1):
      svga_write_control(0x3cf,0x10,value);
      break;
    case (CLGD543x_MMIO_BLTBGCOLOR+2):
      svga_write_control(0x3cf,0x12,value);
      break;
    case (CLGD543x_MMIO_BLTBGCOLOR+3):
      svga_write_control(0x3cf,0x14,value);
      break;
    case (CLGD543x_MMIO_BLTFGCOLOR+0):
      BX_CIRRUS_THIS control.shadow_reg1 = value;
      break;
    case (CLGD543x_MMIO_BLTFGCOLOR+1):
      svga_write_control(0x3cf,0x11,value);
      break;
    case (CLGD543x_MMIO_BLTFGCOLOR+2):
      svga_write_control(0x3cf,0x13,value);
      break;
    case (CLGD543x_MMIO_BLTFGCOLOR+3):
      svga_write_control(0x3cf,0x15,value);
      break;
    case (CLGD543x_MMIO_BLTWIDTH+0):
      svga_write_control(0x3cf,0x20,value);
      break;
    case (CLGD543x_MMIO_BLTWIDTH+1):
      svga_write_control(0x3cf,0x21,value);
      break;
    case (CLGD543x_MMIO_BLTHEIGHT+0):
      svga_write_control(0x3cf,0x22,value);
      break;
    case (CLGD543x_MMIO_BLTHEIGHT+1):
      svga_write_control(0x3cf,0x23,value);
      break;
    case (CLGD543x_MMIO_BLTDESTPITCH+0):
      svga_write_control(0x3cf,0x24,value);
      break;
    case (CLGD543x_MMIO_BLTDESTPITCH+1):
      svga_write_control(0x3cf,0x25,value);
      break;
    case (CLGD543x_MMIO_BLTSRCPITCH+0):
      svga_write_control(0x3cf,0x26,value);
      break;
    case (CLGD543x_MMIO_BLTSRCPITCH+1):
      svga_write_control(0x3cf,0x27,value);
      break;
    case (CLGD543x_MMIO_BLTDESTADDR+0):
      svga_write_control(0x3cf,0x28,value);
      break;
    case (CLGD543x_MMIO_BLTDESTADDR+1):
      svga_write_control(0x3cf,0x29,value);
      break;
    case (CLGD543x_MMIO_BLTDESTADDR+2):
      svga_write_control(0x3cf,0x2a,value);
      break;
    case (CLGD543x_MMIO_BLTDESTADDR+3):
      svga_write_control(0x3cf,0x2b,value);
      break;
    case (CLGD543x_MMIO_BLTSRCADDR+0):
      svga_write_control(0x3cf,0x2c,value);
      break;
    case (CLGD543x_MMIO_BLTSRCADDR+1):
      svga_write_control(0x3cf,0x2d,value);
      break;
    case (CLGD543x_MMIO_BLTSRCADDR+2):
      svga_write_control(0x3cf,0x2e,value);
      break;
    case CLGD543x_MMIO_BLTWRITEMASK:
      svga_write_control(0x3cf,0x2f,value);
      break;
    case CLGD543x_MMIO_BLTMODE:
      svga_write_control(0x3cf,0x30,value);
      break;
    case CLGD543x_MMIO_BLTROP:
      svga_write_control(0x3cf,0x32,value);
      break;
    case CLGD543x_MMIO_BLTMODEEXT:
      svga_write_control(0x3cf,0x33,value);
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLOR+0):
      svga_write_control(0x3cf,0x34,value);
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLOR+1):
      svga_write_control(0x3cf,0x35,value);
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLOR+2):
      BX_ERROR(("CLGD543x_MMIO_BLTTRANSPARENTCOLOR"));
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLOR+3):
      BX_ERROR(("CLGD543x_MMIO_BLTTRANSPARENTCOLOR"));
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK+0):
      svga_write_control(0x3cf,0x38,value);
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK+1):
      svga_write_control(0x3cf,0x39,value);
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK+2):
      BX_ERROR(("CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK"));
      break;
    case (CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK+3):
      BX_ERROR(("CLGD543x_MMIO_BLTTRANSPARENTCOLORMASK"));
      break;
    case CLGD543x_MMIO_BLTSTATUS:
      svga_write_control(0x3cf,0x31,value);
      break;
    default:
      BX_ERROR(("MMIO blt write - address 0x%04x, value 0x%02x",address,value));
      break;
    }
}


/////////////////////////////////////////////////////////////////////////
//
// PCI support
//
/////////////////////////////////////////////////////////////////////////

#if BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI

  void
bx_svga_cirrus_c::svga_init_pcihandlers(void)
{
  int i;

  // addresses
  BX_CIRRUS_THIS pci_memaddr = CIRRUS_PNPMEM_BASE_ADDRESS;
  BX_CIRRUS_THIS pci_mmioaddr = CIRRUS_PNPMMIO_BASE_ADDRESS;
  Bit8u devfunc = 0x00;
  DEV_register_pci_handlers(BX_CIRRUS_THIS_PTR,
     pci_read_handler, pci_write_handler,
     &devfunc, "cirrus", "PCI SVGA Cirrus");

  for (i=0; i<256; i++) {
    BX_CIRRUS_THIS pci_conf[i] = 0x0;
  }

  WriteHostWordToLittleEndian(
    &BX_CIRRUS_THIS pci_conf[0x00], PCI_VENDOR_CIRRUS);
  WriteHostWordToLittleEndian(
    &BX_CIRRUS_THIS pci_conf[0x02], PCI_DEVICE_CLGD5446);
  WriteHostWordToLittleEndian(
    &BX_CIRRUS_THIS pci_conf[0x04],
    (PCI_COMMAND_IOACCESS | PCI_COMMAND_MEMACCESS));
  BX_CIRRUS_THIS pci_conf[0x0a] = PCI_CLASS_SUB_VGA;
  BX_CIRRUS_THIS pci_conf[0x0b] = PCI_CLASS_BASE_DISPLAY;
  BX_CIRRUS_THIS pci_conf[0x0e] = PCI_CLASS_HEADERTYPE_00h;
}

  Bit32u
bx_svga_cirrus_c::pci_read_handler(void *this_ptr, Bit8u address, unsigned io_len)
{
#if !BX_USE_CIRRUS_SMF
  return ((bx_svga_cirrus_c *)this_ptr)->pci_read(address,io_len);
}

  Bit32u
bx_svga_cirrus_c::pci_read(Bit8u address, unsigned io_len)
{
#endif // !BX_USE_CIRRUS_SMF
  unsigned i;
  Bit32u ret;

  if (io_len > 4) {
    BX_PANIC(("pci_read: io_len > 4!"));
    return 0xffffffff;
    }
  if (((unsigned)address + io_len) > 256) {
    BX_PANIC(("pci_read: (address + io_len) > 256!"));
    return 0xffffffff;
    }

  ret = 0;
  for (i = 0; i < io_len; i++) {
    ret |= (Bit32u)(BX_CIRRUS_THIS pci_conf[address + i]) << (i*8);
    }

  BX_DEBUG(("pci_read: address 0x%02x, io_len 0x%02x, value 0x%x",
    (unsigned)address, (unsigned)io_len, (unsigned)ret));

  return ret;
}

  void
bx_svga_cirrus_c::pci_write_handler(void *this_ptr, Bit8u address, Bit32u value, unsigned io_len)
{
#if !BX_USE_CIRRUS_SMF
  ((bx_svga_cirrus_c *)this_ptr)->pci_write(address,value,io_len);
}

  void
bx_svga_cirrus_c::pci_write(Bit8u address, Bit32u value, unsigned io_len)
{
#endif // !BX_USE_CIRRUS_SMF
  unsigned i;
  unsigned write_addr;
  Bit8u new_value, old_value;
  bx_bool baseaddr0_change = 0;
  bx_bool baseaddr1_change = 0;

  BX_DEBUG(("pci_write: address 0x%02x, io_len 0x%02x, value 0x%x",
    (unsigned)address, (unsigned)io_len, (unsigned)value));

  if ((address > 0x17) && (address < 0x34))
    return;
  if (io_len <= 4) {
    for (i = 0; i < io_len; i++) {
      write_addr = address + i;
      old_value = BX_CIRRUS_THIS pci_conf[write_addr];
      new_value = (Bit8u)(value & 0xff);
      switch (write_addr) {
        case 0x04: // command bit0-7
          new_value &= PCI_COMMAND_IOACCESS | PCI_COMMAND_MEMACCESS;
          new_value |= old_value & ~(PCI_COMMAND_IOACCESS | PCI_COMMAND_MEMACCESS);
          break;
        case 0x05: // command bit8-15
          new_value = old_value;
          break;
        case 0x06: // status bit0-7
          new_value = old_value & (~new_value);
          break;
        case 0x07: // status bit8-15
          new_value = old_value & (~new_value);
          break;

        case 0x10: case 0x11: case 0x12: case 0x13: // base address #0
          baseaddr0_change = (old_value != new_value);
          break;
        case 0x14: case 0x15: case 0x16: case 0x17: // base address #1
          baseaddr1_change = (old_value != new_value);
          break;

        // read-only.
        case 0x00: case 0x01: // vendor
        case 0x02: case 0x03: // device
        case 0x08: // revision
        case 0x09: case 0x0a: case 0x0b: // class
        case 0x0e: // header type
        case 0x0f: // built-in self test(unimplemented)
          new_value = old_value;
          break;
        default:
          break;
      }
      BX_CIRRUS_THIS pci_conf[write_addr] = new_value;
      value >>= 8;
    }
    if (baseaddr0_change) {
      DEV_pci_set_base_mem(BX_CIRRUS_THIS_PTR, cirrus_mem_read_handler,
                           cirrus_mem_write_handler,
                           &BX_CIRRUS_THIS pci_memaddr,
                           &BX_CIRRUS_THIS pci_conf[0x10],
                           CIRRUS_PNPMEM_SIZE);
      BX_INFO(("new pci_memaddr: 0x%04x", BX_CIRRUS_THIS pci_memaddr));
    }
    if (baseaddr1_change) {
      DEV_pci_set_base_mem(BX_CIRRUS_THIS_PTR, cirrus_mem_read_handler,
                           cirrus_mem_write_handler,
                           &BX_CIRRUS_THIS pci_mmioaddr,
                           &BX_CIRRUS_THIS pci_conf[0x14],
                           CIRRUS_PNPMMIO_SIZE);
      BX_INFO(("new pci_mmioaddr = 0x%08x", BX_CIRRUS_THIS pci_mmioaddr));
    }
  }
}

#endif // BX_SUPPORT_PCI && BX_SUPPORT_CLGD54XX_PCI

/////////////////////////////////////////////////////////////////////////
//
// Bitblt.
//
/////////////////////////////////////////////////////////////////////////

  void
bx_svga_cirrus_c::svga_reset_bitblt(void)
{
  BX_CIRRUS_THIS control.reg[0x31] &= ~(CIRRUS_BLT_START|CIRRUS_BLT_BUSY|CIRRUS_BLT_FIFOUSED);
  BX_CIRRUS_THIS bitblt.rop_handler = NULL;
  BX_CIRRUS_THIS bitblt.src = NULL;
  BX_CIRRUS_THIS bitblt.dst = NULL;
  BX_CIRRUS_THIS bitblt.memsrc_ptr = NULL;
  BX_CIRRUS_THIS bitblt.memsrc_endptr = NULL;
  BX_CIRRUS_THIS bitblt.memsrc_needed = 0;
  BX_CIRRUS_THIS bitblt.memdst_ptr = NULL;
  BX_CIRRUS_THIS bitblt.memdst_endptr = NULL;
  BX_CIRRUS_THIS bitblt.memdst_needed = 0;
}

  void
bx_svga_cirrus_c::svga_bitblt()
{
  Bit16u tmp16;
  Bit32u tmp32;
  Bit32u dstaddr;
  Bit32u srcaddr;
  Bit32u offset;

  ReadHostWordFromLittleEndian(&BX_CIRRUS_THIS control.reg[0x20],tmp16);
  BX_CIRRUS_THIS bitblt.bltwidth = ((int)tmp16 & (int)0x1fff) + 1;
  ReadHostWordFromLittleEndian(&BX_CIRRUS_THIS control.reg[0x22],tmp16);
  BX_CIRRUS_THIS bitblt.bltheight = ((int)tmp16 & (int)0x1fff) + 1;
  ReadHostWordFromLittleEndian(&BX_CIRRUS_THIS control.reg[0x24],tmp16);
  BX_CIRRUS_THIS bitblt.dstpitch = (int)tmp16 & (int)0x1fff;
  ReadHostWordFromLittleEndian(&BX_CIRRUS_THIS control.reg[0x26],tmp16);
  BX_CIRRUS_THIS bitblt.srcpitch = (int)tmp16 & (int)0x1fff;
  ReadHostDWordFromLittleEndian(&BX_CIRRUS_THIS control.reg[0x28],tmp32);
  dstaddr = tmp32 & (Bit32u)0x003fffff;
  ReadHostDWordFromLittleEndian(&BX_CIRRUS_THIS control.reg[0x2c],tmp32);
  srcaddr = tmp32 & (Bit32u)0x003fffff;
  BX_CIRRUS_THIS bitblt.srcaddr = srcaddr;
  BX_CIRRUS_THIS bitblt.bltmode = BX_CIRRUS_THIS control.reg[0x30];
  BX_CIRRUS_THIS bitblt.bltmodeext = BX_CIRRUS_THIS control.reg[0x33];
  BX_CIRRUS_THIS bitblt.bltrop = BX_CIRRUS_THIS control.reg[0x32];
  BX_CIRRUS_THIS bitblt.async_xbytes = 0;
  BX_CIRRUS_THIS bitblt.async_y = 0;
  offset = dstaddr - (BX_CIRRUS_THIS disp_ptr - BX_CIRRUS_THIS vidmem);
  BX_CIRRUS_THIS bitblt.pos_x = (offset % BX_CIRRUS_THIS bitblt.dstpitch) / (BX_CIRRUS_THIS svga_bpp >> 3);
  BX_CIRRUS_THIS bitblt.pos_y = offset / BX_CIRRUS_THIS bitblt.dstpitch;

  BX_INFO(("BLT: src:0x%08x,dst 0x%08x,block %ux%u,mode 0x%02x,ROP 0x%02x",
    (unsigned)srcaddr,(unsigned)dstaddr,
    (unsigned)BX_CIRRUS_THIS bitblt.bltwidth,(unsigned)BX_CIRRUS_THIS bitblt.bltheight,
    (unsigned)BX_CIRRUS_THIS bitblt.bltmode,(unsigned)BX_CIRRUS_THIS bitblt.bltrop));
  BX_INFO(("BLT: srcpitch:0x%08x,dstpitch 0x%08x,modeext 0x%02x",
    (unsigned)BX_CIRRUS_THIS bitblt.srcpitch,
    (unsigned)BX_CIRRUS_THIS bitblt.dstpitch,
    (unsigned)BX_CIRRUS_THIS bitblt.bltmodeext));
  BX_INFO(("BLT: dst x = %d, dst y = %d", BX_CIRRUS_THIS bitblt.pos_x, BX_CIRRUS_THIS bitblt.pos_y));

  switch (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_PIXELWIDTHMASK) {
    case CIRRUS_BLTMODE_PIXELWIDTH8:
      BX_CIRRUS_THIS bitblt.pixelwidth = 1;
      break;
    case CIRRUS_BLTMODE_PIXELWIDTH16:
      BX_CIRRUS_THIS bitblt.pixelwidth = 2;
      break;
    case CIRRUS_BLTMODE_PIXELWIDTH24:
      BX_CIRRUS_THIS bitblt.pixelwidth = 3;
      break;
    case CIRRUS_BLTMODE_PIXELWIDTH32:
      BX_CIRRUS_THIS bitblt.pixelwidth = 4;
      break;
    default:
      BX_PANIC(("unknown pixel width"));
      goto ignoreblt;
    }
  BX_CIRRUS_THIS bitblt.bltwidth /= BX_CIRRUS_THIS bitblt.pixelwidth;
  BX_CIRRUS_THIS bitblt.bltmode &= ~CIRRUS_BLTMODE_PIXELWIDTHMASK;

  if ((BX_CIRRUS_THIS bitblt.bltmode & (CIRRUS_BLTMODE_MEMSYSSRC|CIRRUS_BLTMODE_MEMSYSDEST))
                                   == (CIRRUS_BLTMODE_MEMSYSSRC|CIRRUS_BLTMODE_MEMSYSDEST)) {
    BX_ERROR(("BLT: memory-to-memory copy is requested, ROP %02x",
      (unsigned)BX_CIRRUS_THIS bitblt.bltrop));
    goto ignoreblt;
    }

  if ((BX_CIRRUS_THIS bitblt.bltmodeext & CIRRUS_BLTMODEEXT_SOLIDFILL) &&
      (BX_CIRRUS_THIS bitblt.bltmode & (CIRRUS_BLTMODE_MEMSYSDEST | 
                             CIRRUS_BLTMODE_TRANSPARENTCOMP |
                             CIRRUS_BLTMODE_PATTERNCOPY | 
                             CIRRUS_BLTMODE_COLOREXPAND)) == 
      (CIRRUS_BLTMODE_PATTERNCOPY | CIRRUS_BLTMODE_COLOREXPAND)) {
    BX_CIRRUS_THIS bitblt.rop_handler = svga_get_fwd_rop_handler(BX_CIRRUS_THIS bitblt.bltrop);
    BX_CIRRUS_THIS bitblt.dst = BX_CIRRUS_THIS vidmem + dstaddr;
    svga_solidfill();
  } else {

    if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_BACKWARDS) {
      BX_CIRRUS_THIS bitblt.dstpitch = -BX_CIRRUS_THIS bitblt.dstpitch;
      BX_CIRRUS_THIS bitblt.srcpitch = -BX_CIRRUS_THIS bitblt.srcpitch;
      BX_CIRRUS_THIS bitblt.rop_handler = svga_get_bkwd_rop_handler(BX_CIRRUS_THIS bitblt.bltrop);
      }
    else {
      BX_CIRRUS_THIS bitblt.rop_handler = svga_get_fwd_rop_handler(BX_CIRRUS_THIS bitblt.bltrop);
      }

    // setup bitblt engine.
    if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_MEMSYSSRC) {
      svga_setup_bitblt_cputovideo(dstaddr,srcaddr);
      }
    else if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_MEMSYSDEST) {
      svga_setup_bitblt_videotocpu(dstaddr,srcaddr);
      }
    else {
      svga_setup_bitblt_videotovideo(dstaddr,srcaddr);
      }
    return;
  }

ignoreblt:
  svga_reset_bitblt();
  return;
}

  void
bx_svga_cirrus_c::svga_setup_bitblt_cputovideo(Bit32u dstaddr,Bit32u srcaddr)
{
  BX_CIRRUS_THIS bitblt.bltmode &= ~CIRRUS_BLTMODE_MEMSYSSRC;

  BX_CIRRUS_THIS bitblt.dst = BX_CIRRUS_THIS vidmem + dstaddr;
  BX_CIRRUS_THIS bitblt.src = NULL;

  BX_CIRRUS_THIS bitblt.memsrc_ptr = &BX_CIRRUS_THIS bitblt.memsrc[0];
  BX_CIRRUS_THIS bitblt.memsrc_endptr = &BX_CIRRUS_THIS bitblt.memsrc[0];

  if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_PATTERNCOPY) {
    if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_COLOREXPAND) {
      BX_CIRRUS_THIS bitblt.memsrc_needed = 8;
      }
    else {
      BX_CIRRUS_THIS bitblt.memsrc_needed = 8 * 8 * BX_CIRRUS_THIS bitblt.pixelwidth;
      }
    if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_TRANSPARENTCOMP) {
      BX_ERROR(("BLT: patterncopy: TRANSPARENTCOMP is not implemented"));
      }
    else {
      BX_CIRRUS_THIS bitblt.bitblt_ptr = svga_patterncopy_memsrc_static;
      }
    }
  else {
    BX_CIRRUS_THIS bitblt.memdst_bytesperline =
        BX_CIRRUS_THIS bitblt.bltwidth * BX_CIRRUS_THIS bitblt.pixelwidth;
    if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_COLOREXPAND) {
      BX_CIRRUS_THIS bitblt.memsrc_bytesperline =
          (BX_CIRRUS_THIS bitblt.bltwidth + 7) / 8;
      }
    else {
      BX_CIRRUS_THIS bitblt.memsrc_bytesperline = BX_CIRRUS_THIS bitblt.memdst_bytesperline;
      }
    BX_CIRRUS_THIS bitblt.memsrc_needed =
        BX_CIRRUS_THIS bitblt.memsrc_bytesperline * BX_CIRRUS_THIS bitblt.bltheight;
    BX_CIRRUS_THIS bitblt.memsrc_needed = (BX_CIRRUS_THIS bitblt.memsrc_needed + 3) & (~3);
    if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_TRANSPARENTCOMP) {
      BX_CIRRUS_THIS bitblt.bitblt_ptr = svga_simplebitblt_transp_memsrc_static;
      }
    else {
      BX_CIRRUS_THIS bitblt.bitblt_ptr = svga_simplebitblt_memsrc_static;
      }
    }

  svga_asyncbitblt_next();
}

  void
bx_svga_cirrus_c::svga_setup_bitblt_videotocpu(Bit32u dstaddr,Bit32u srcaddr)
{
  BX_ERROR(("BLT: MEMSYSDEST is not implemented"));

  BX_CIRRUS_THIS bitblt.bltmode &= ~CIRRUS_BLTMODE_MEMSYSDEST;

#if 0
  BX_CIRRUS_THIS bitblt.dst = NULL;
  BX_CIRRUS_THIS bitblt.src = BX_CIRRUS_THIS vidmem + srcaddr;

  BX_CIRRUS_THIS bitblt.memdst_ptr = &BX_CIRRUS_THIS bitblt.memdst[0];
  BX_CIRRUS_THIS bitblt.memdst_endptr = &BX_CIRRUS_THIS bitblt.memdst[0];

  BX_CIRRUS_THIS bitblt.memdst_needed =
    BX_CIRRUS_THIS bitblt.bltwidth * BX_CIRRUS_THIS bitblt.pixelwidth * BX_CIRRUS_THIS bitblt.bltheight;
  BX_CIRRUS_THIS bitblt.memdst_needed = (BX_CIRRUS_THIS bitblt.memdst_needed + 3) & (~3);

  if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_PATTERNCOPY) {
    BX_CIRRUS_THIS bitblt.bitblt_ptr = svga_patterncopy_memdst_static;
    }
  else {
    BX_CIRRUS_THIS bitblt.bitblt_ptr = svga_simplebitblt_memdst_static;
    }

  svga_asyncbitblt_next();
#endif
}

  void
bx_svga_cirrus_c::svga_setup_bitblt_videotovideo(Bit32u dstaddr,Bit32u srcaddr)
{
  BX_CIRRUS_THIS bitblt.dst = BX_CIRRUS_THIS vidmem + dstaddr;
  BX_CIRRUS_THIS bitblt.src = BX_CIRRUS_THIS vidmem + srcaddr;

  if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_PATTERNCOPY) {
    BX_CIRRUS_THIS bitblt.bitblt_ptr = svga_patterncopy_static;
    }
  else {
    BX_CIRRUS_THIS bitblt.bitblt_ptr = svga_simplebitblt_static;
    }

  (*BX_CIRRUS_THIS bitblt.bitblt_ptr)();
  svga_reset_bitblt();
  BX_CIRRUS_THIS redraw_area(BX_CIRRUS_THIS bitblt.pos_x, BX_CIRRUS_THIS bitblt.pos_y,
                             BX_CIRRUS_THIS bitblt.bltwidth, BX_CIRRUS_THIS bitblt.bltheight);
}


  void
bx_svga_cirrus_c::svga_colorexpand(Bit8u *dst,const Bit8u *src,int count,int pixelwidth)
{
  BX_DEBUG(("svga_cirrus: COLOR EXPAND"));

  switch (pixelwidth) {
    case 1:
      svga_colorexpand_8(dst,src,count);
      break;
    case 2:
      svga_colorexpand_16(dst,src,count);
      break;
    case 3:
      svga_colorexpand_24(dst,src,count);
      break;
    case 4:
      svga_colorexpand_32(dst,src,count);
      break;
    default:
      BX_PANIC(("COLOREXPAND: unknown pixelwidth %u",(unsigned)pixelwidth));
      break;
    }
}

#if !BX_USE_CIRRUS_SMF
  void
bx_svga_cirrus_c::svga_colorexpand_8_static(void *this_ptr,Bit8u *dst,const Bit8u *src,int count)
{
  ((bx_svga_cirrus_c *)this_ptr)->svga_colorexpand_8(dst,src,count);
}

  void
bx_svga_cirrus_c::svga_colorexpand_16_static(void *this_ptr,Bit8u *dst,const Bit8u *src,int count)
{
  ((bx_svga_cirrus_c *)this_ptr)->svga_colorexpand_16(dst,src,count);
}

  void
bx_svga_cirrus_c::svga_colorexpand_24_static(void *this_ptr,Bit8u *dst,const Bit8u *src,int count)
{
  ((bx_svga_cirrus_c *)this_ptr)->svga_colorexpand_24(dst,src,count);
}

  void
bx_svga_cirrus_c::svga_colorexpand_32_static(void *this_ptr,Bit8u *dst,const Bit8u *src,int count)
{
  ((bx_svga_cirrus_c *)this_ptr)->svga_colorexpand_32(dst,src,count);
}

#endif // BX_USE_CIRRUS_SMF

  void
bx_svga_cirrus_c::svga_colorexpand_8(Bit8u *dst,const Bit8u *src,int count)
{
  int x;
  Bit8u colors[2];
  unsigned bits;
  unsigned bitmask;
  int srcskipleft = BX_CIRRUS_THIS control.reg[0x2f] & 0x07;

  colors[0] = BX_CIRRUS_THIS control.shadow_reg0;
  colors[1] = BX_CIRRUS_THIS control.shadow_reg1;

  bitmask = 0x80 >> srcskipleft;
  bits = *src++;
  for (x = 0; x < count; x++) {
    if ((bitmask & 0xff) == 0) {
      bitmask = 0x80;
      bits = *src++;
      }
    *dst++ = colors[!!(bits & bitmask)];
    bitmask >>= 1;
    }
}

  void
bx_svga_cirrus_c::svga_colorexpand_16(Bit8u *dst,const Bit8u *src,int count)
{
  int x;
  Bit8u colors[2][2];
  unsigned bits;
  unsigned bitmask;
  unsigned index;
  int srcskipleft = BX_CIRRUS_THIS control.reg[0x2f] & 0x07;

  colors[0][0] = BX_CIRRUS_THIS control.shadow_reg0;
  colors[0][1] = BX_CIRRUS_THIS control.reg[0x10];
  colors[1][0] = BX_CIRRUS_THIS control.shadow_reg1;
  colors[1][1] = BX_CIRRUS_THIS control.reg[0x11];

  bitmask = 0x80 >> srcskipleft;
  bits = *src++;
  for (x = 0; x < count; x++) {
    if ((bitmask & 0xff) == 0) {
      bitmask = 0x80;
      bits = *src++;
      }
    index = !!(bits & bitmask);
    *dst++ = colors[index][0];
    *dst++ = colors[index][1];
    bitmask >>= 1;
    }
}

  void
bx_svga_cirrus_c::svga_colorexpand_24(Bit8u *dst,const Bit8u *src,int count)
{
  int x;
  Bit8u colors[2][3];
  unsigned bits;
  unsigned bitmask;
  unsigned index;
  int srcskipleft = BX_CIRRUS_THIS control.reg[0x2f] & 0x07;

  colors[0][0] = BX_CIRRUS_THIS control.shadow_reg0;
  colors[0][1] = BX_CIRRUS_THIS control.reg[0x10];
  colors[0][2] = BX_CIRRUS_THIS control.reg[0x12];
  colors[1][0] = BX_CIRRUS_THIS control.shadow_reg1;
  colors[1][1] = BX_CIRRUS_THIS control.reg[0x11];
  colors[1][2] = BX_CIRRUS_THIS control.reg[0x13];

  bitmask = 0x80 >> srcskipleft;
  bits = *src++;
  for (x = 0; x < count; x++) {
    if ((bitmask & 0xff) == 0) {
      bitmask = 0x80;
      bits = *src++;
      }
    index = !!(bits & bitmask);
    *dst++ = colors[index][0];
    *dst++ = colors[index][1];
    *dst++ = colors[index][2];
    bitmask >>= 1;
    }
}

  void
bx_svga_cirrus_c::svga_colorexpand_32(Bit8u *dst,const Bit8u *src,int count)
{
  int x;
  Bit8u colors[2][4];
  unsigned bits;
  unsigned bitmask;
  unsigned index;
  int srcskipleft = BX_CIRRUS_THIS control.reg[0x2f] & 0x07;

  colors[0][0] = BX_CIRRUS_THIS control.shadow_reg0;
  colors[0][1] = BX_CIRRUS_THIS control.reg[0x10];
  colors[0][2] = BX_CIRRUS_THIS control.reg[0x12];
  colors[0][3] = BX_CIRRUS_THIS control.reg[0x14];
  colors[1][0] = BX_CIRRUS_THIS control.shadow_reg1;
  colors[1][1] = BX_CIRRUS_THIS control.reg[0x11];
  colors[1][2] = BX_CIRRUS_THIS control.reg[0x13];
  colors[1][3] = BX_CIRRUS_THIS control.reg[0x15];

  bitmask = 0x80 >> srcskipleft;
  bits = *src++;
  for (x = 0; x < count; x++) {
    if ((bitmask & 0xff) == 0) {
      bitmask = 0x80;
      bits = *src++;
      }
    index = !!(bits & bitmask);
    *dst++ = colors[index][0];
    *dst++ = colors[index][1];
    *dst++ = colors[index][2];
    *dst++ = colors[index][3];
    bitmask >>= 1;
    }
}

#if !BX_USE_CIRRUS_SMF
  void
bx_svga_cirrus_c::svga_patterncopy_static(void *this_ptr)
{
  ((bx_svga_cirrus_c *)this_ptr)->svga_patterncopy();
}

  void
bx_svga_cirrus_c::svga_simplebitblt_static(void *this_ptr)
{
  ((bx_svga_cirrus_c *)this_ptr)->svga_simplebitblt();
}

  void
bx_svga_cirrus_c::svga_patterncopy_memsrc_static(void *this_ptr)
{
  ((bx_svga_cirrus_c *)this_ptr)->svga_patterncopy_memsrc();
}

  void
bx_svga_cirrus_c::svga_simplebitblt_memsrc_static(void *this_ptr)
{
  ((bx_svga_cirrus_c *)this_ptr)->svga_simplebitblt_memsrc();
}

  void
bx_svga_cirrus_c::svga_simplebitblt_transp_memsrc_static(void *this_ptr)
{
  ((bx_svga_cirrus_c *)this_ptr)->svga_simplebitblt_transp_memsrc();
}

#endif // !BX_USE_CIRRUS_SMF

  void
bx_svga_cirrus_c::svga_patterncopy()
{
  Bit8u color[4];
  Bit8u work_colorexp[256];
  Bit8u *src, *dst;
  Bit8u *dstc, *srcc;
  int x,y, pattern_y;
  int tilewidth;
  int patternbytes = 8 * BX_CIRRUS_THIS bitblt.pixelwidth;
  int bltbytes = BX_CIRRUS_THIS bitblt.bltwidth * BX_CIRRUS_THIS bitblt.pixelwidth;
  unsigned bits, bits_xor, bitmask;
  int srcskipleft = BX_CIRRUS_THIS control.reg[0x2f] & 0x07;

  if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_COLOREXPAND) {
    if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_TRANSPARENTCOMP) {
      if (BX_CIRRUS_THIS bitblt.bltmodeext & CIRRUS_BLTMODEEXT_COLOREXPINV) {
        color[0] = BX_CIRRUS_THIS control.shadow_reg0;
        color[1] = BX_CIRRUS_THIS control.reg[0x10];
        color[2] = BX_CIRRUS_THIS control.reg[0x12];
        color[3] = BX_CIRRUS_THIS control.reg[0x14];
        bits_xor = 0xff;
      } else {
        color[0] = BX_CIRRUS_THIS control.shadow_reg1;
        color[1] = BX_CIRRUS_THIS control.reg[0x11];
        color[2] = BX_CIRRUS_THIS control.reg[0x13];
        color[3] = BX_CIRRUS_THIS control.reg[0x15];
        bits_xor = 0x00;
      }

      pattern_y = 0;
      for (y = 0; y < BX_CIRRUS_THIS bitblt.bltheight; y++) {
        dst = BX_CIRRUS_THIS bitblt.dst;
        bitmask = 0x80 >> srcskipleft;
        bits = BX_CIRRUS_THIS bitblt.src[pattern_y] ^ bits_xor;
        for (x = 0; x < BX_CIRRUS_THIS bitblt.bltwidth; x++) {
          if ((bitmask & 0xff) == 0) {
            bitmask = 0x80;
            bits = BX_CIRRUS_THIS bitblt.src[pattern_y] ^ bits_xor;
          }
          if (bits & bitmask) {
            (*BX_CIRRUS_THIS bitblt.rop_handler)(
              dst, &color[0], 0, 0, BX_CIRRUS_THIS bitblt.pixelwidth, 1);
          }
          dst += BX_CIRRUS_THIS bitblt.pixelwidth;
          bitmask >>= 1;
        }
        pattern_y = (pattern_y + 1) & 7;
        BX_CIRRUS_THIS bitblt.dst += BX_CIRRUS_THIS bitblt.dstpitch;
      }
      return;
    } else {
      svga_colorexpand(work_colorexp,BX_CIRRUS_THIS bitblt.src,8*8,BX_CIRRUS_THIS bitblt.pixelwidth);
      BX_CIRRUS_THIS bitblt.src = work_colorexp;
      BX_CIRRUS_THIS bitblt.bltmode &= ~CIRRUS_BLTMODE_COLOREXPAND;
    }
  }
  if (BX_CIRRUS_THIS bitblt.bltmode & ~CIRRUS_BLTMODE_PATTERNCOPY) {
    BX_ERROR(("PATTERNCOPY: unknown bltmode %02x",BX_CIRRUS_THIS bitblt.bltmode));
    return;
  }

  BX_DEBUG(("svga_cirrus: PATTERN COPY"));
  dst = BX_CIRRUS_THIS bitblt.dst;
  pattern_y = BX_CIRRUS_THIS bitblt.srcaddr & 0x07;
  src = (Bit8u *)BX_CIRRUS_THIS bitblt.src;
  src -= (pattern_y * BX_CIRRUS_THIS bitblt.pixelwidth);
  for (y = 0; y < BX_CIRRUS_THIS bitblt.bltheight; y++) {
    srcc = src + pattern_y * patternbytes;
    dstc = dst;
    for (x = 0; x < bltbytes; x += patternbytes) {
      tilewidth = BX_MIN(patternbytes,bltbytes - x);
      (*BX_CIRRUS_THIS bitblt.rop_handler)(
        dstc, srcc, 0, patternbytes,
        tilewidth, 1);
      dstc += patternbytes;
    }
    pattern_y = (pattern_y + 1) & 7;
    dst += BX_CIRRUS_THIS bitblt.dstpitch;
  }
}

  void
bx_svga_cirrus_c::svga_simplebitblt()
{
  Bit8u color[4];
  Bit8u work_colorexp[2048];
  int x, y;
  Bit8u *dst;
  unsigned bits, bits_xor, bitmask;
  int srcskipleft = BX_CIRRUS_THIS control.reg[0x2f] & 0x07;

  if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_COLOREXPAND) {
    if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_TRANSPARENTCOMP) {
      if (BX_CIRRUS_THIS bitblt.bltmodeext & CIRRUS_BLTMODEEXT_COLOREXPINV) {
        color[0] = BX_CIRRUS_THIS control.shadow_reg0;
        color[1] = BX_CIRRUS_THIS control.reg[0x10];
        color[2] = BX_CIRRUS_THIS control.reg[0x12];
        color[3] = BX_CIRRUS_THIS control.reg[0x14];
        bits_xor = 0xff;
      } else {
        color[0] = BX_CIRRUS_THIS control.shadow_reg1;
        color[1] = BX_CIRRUS_THIS control.reg[0x11];
        color[2] = BX_CIRRUS_THIS control.reg[0x13];
        color[3] = BX_CIRRUS_THIS control.reg[0x15];
        bits_xor = 0x00;
      }

      for (y = 0; y < BX_CIRRUS_THIS bitblt.bltheight; y++) {
        dst = BX_CIRRUS_THIS bitblt.dst;
        bitmask = 0x80 >> srcskipleft;
        bits = *BX_CIRRUS_THIS bitblt.src++ ^ bits_xor;
        for (x = 0; x < BX_CIRRUS_THIS bitblt.bltwidth; x++) {
          if ((bitmask & 0xff) == 0) {
            bitmask = 0x80;
            bits = *BX_CIRRUS_THIS bitblt.src++ ^ bits_xor;
          }
          if (bits & bitmask) {
            (*BX_CIRRUS_THIS bitblt.rop_handler)(
              dst, &color[0], 0, 0, BX_CIRRUS_THIS bitblt.pixelwidth, 1);
          }
          dst += BX_CIRRUS_THIS bitblt.pixelwidth;
          bitmask >>= 1;
        }
        BX_CIRRUS_THIS bitblt.dst += BX_CIRRUS_THIS bitblt.dstpitch;
      }
      return;
    } else {
      for (y = 0; y < BX_CIRRUS_THIS bitblt.bltheight; y++) {
        svga_colorexpand(work_colorexp,BX_CIRRUS_THIS bitblt.src,BX_CIRRUS_THIS bitblt.bltwidth,
                         BX_CIRRUS_THIS bitblt.pixelwidth);
        (*BX_CIRRUS_THIS bitblt.rop_handler)(
          BX_CIRRUS_THIS bitblt.dst, work_colorexp, 0, 0,
          BX_CIRRUS_THIS bitblt.bltwidth * BX_CIRRUS_THIS bitblt.pixelwidth, 1);
        BX_CIRRUS_THIS bitblt.src += ((BX_CIRRUS_THIS bitblt.bltwidth + 7) / 8);
        BX_CIRRUS_THIS bitblt.dst += BX_CIRRUS_THIS bitblt.dstpitch;
      }
      return;
    }
  }
  if (BX_CIRRUS_THIS bitblt.bltmode & ~CIRRUS_BLTMODE_BACKWARDS) {
    BX_ERROR(("SIMPLE BLT: unknown bltmode %02x",BX_CIRRUS_THIS bitblt.bltmode));
    return;
    }

  BX_DEBUG(("svga_cirrus: BITBLT"));
  (*BX_CIRRUS_THIS bitblt.rop_handler)(
    BX_CIRRUS_THIS bitblt.dst, BX_CIRRUS_THIS bitblt.src,
    BX_CIRRUS_THIS bitblt.dstpitch, BX_CIRRUS_THIS bitblt.srcpitch,
    BX_CIRRUS_THIS bitblt.bltwidth * BX_CIRRUS_THIS bitblt.pixelwidth, BX_CIRRUS_THIS bitblt.bltheight
    );
}

  void
bx_svga_cirrus_c::svga_solidfill()
{
  Bit8u color[4];
  int x, y;
  Bit8u *dst;

  BX_DEBUG(("BLT: SOLIDFILL"));

  color[0] = BX_CIRRUS_THIS control.shadow_reg1;
  color[1] = BX_CIRRUS_THIS control.reg[0x11];
  color[2] = BX_CIRRUS_THIS control.reg[0x13];
  color[3] = BX_CIRRUS_THIS control.reg[0x15];

  for (y = 0; y < BX_CIRRUS_THIS bitblt.bltheight; y++) {
    dst = BX_CIRRUS_THIS bitblt.dst;
    for (x = 0; x < BX_CIRRUS_THIS bitblt.bltwidth; x++) {
      (*BX_CIRRUS_THIS bitblt.rop_handler)(
        dst, &color[0], 0, 0, BX_CIRRUS_THIS bitblt.pixelwidth, 1);
        dst += BX_CIRRUS_THIS bitblt.pixelwidth;
    }
    BX_CIRRUS_THIS bitblt.dst += BX_CIRRUS_THIS bitblt.dstpitch;
  }
  BX_CIRRUS_THIS redraw_area(BX_CIRRUS_THIS bitblt.pos_x, BX_CIRRUS_THIS bitblt.pos_y,
                             BX_CIRRUS_THIS bitblt.bltwidth, BX_CIRRUS_THIS bitblt.bltheight);
}

  void
bx_svga_cirrus_c::svga_patterncopy_memsrc()
{
  int srcavail = BX_CIRRUS_THIS bitblt.memsrc_ptr - &BX_CIRRUS_THIS bitblt.memsrc[0];

  if (srcavail > 0) {
    if (srcavail != BX_CIRRUS_THIS bitblt.memsrc_needed) {
      BX_PANIC(("CIRRUS_BLT_CACHESIZE is too small"));
      BX_CIRRUS_THIS bitblt.memsrc_needed = 0;
      return;
    }
    BX_INFO(("svga_patterncopy_memsrc() - not tested"));

    BX_CIRRUS_THIS bitblt.src = &BX_CIRRUS_THIS bitblt.memsrc[0];
    svga_patterncopy();
    BX_CIRRUS_THIS redraw_area(BX_CIRRUS_THIS bitblt.pos_x, BX_CIRRUS_THIS bitblt.pos_y,
                               BX_CIRRUS_THIS bitblt.bltwidth, BX_CIRRUS_THIS bitblt.bltheight);
  }
}

  void
bx_svga_cirrus_c::svga_simplebitblt_memsrc()
{
  Bit8u work_colorexp[256];
  int srcavail = BX_CIRRUS_THIS bitblt.memsrc_ptr - &BX_CIRRUS_THIS bitblt.memsrc[0];
  int bytesavail;
  int bytesprocessed;
  int total;
  Bit8u *srcptr = &BX_CIRRUS_THIS bitblt.memsrc[0];
  Bit8u *srccurptr;
  int srccuravail;

  BX_DEBUG(("svga_cirrus: BLT, cpu-to-video"));
  total = 0;
  while (1) {
    bytesavail = BX_CIRRUS_THIS bitblt.memsrc_bytesperline - BX_CIRRUS_THIS bitblt.async_xbytes;
    bytesavail = BX_MIN(bytesavail,srcavail);
    if (bytesavail <= 0)
      break;

    bytesprocessed = bytesavail;
    srccurptr = srcptr;
    srccuravail = bytesavail;
    if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_COLOREXPAND) {
      if (BX_CIRRUS_THIS bitblt.bltmode & ~CIRRUS_BLTMODE_COLOREXPAND) {
        BX_ERROR(("cpu-to-video BLT: unknown bltmode %02x",BX_CIRRUS_THIS bitblt.bltmode));
        return;
        }

      bytesprocessed = BX_MIN(256/32,bytesavail);
      svga_colorexpand(work_colorexp,srcptr,bytesprocessed * 8,BX_CIRRUS_THIS bitblt.pixelwidth);
      srccurptr = work_colorexp;
      srccuravail = BX_MIN(
          bytesprocessed * 8 * BX_CIRRUS_THIS bitblt.pixelwidth,
          BX_CIRRUS_THIS bitblt.memdst_bytesperline - BX_CIRRUS_THIS bitblt.async_xbytes * 8 * BX_CIRRUS_THIS bitblt.pixelwidth);
      }
    else {
      if (BX_CIRRUS_THIS bitblt.bltmode != 0) {
        BX_ERROR(("cpu-to-video BLT: unknown bltmode %02x",BX_CIRRUS_THIS bitblt.bltmode));
        return;
        }
      }

    (*BX_CIRRUS_THIS bitblt.rop_handler)(
        BX_CIRRUS_THIS bitblt.dst, srccurptr, 0, 0, srccuravail, 1);

    BX_CIRRUS_THIS bitblt.dst += srccuravail;
    total += bytesprocessed;
    srcptr += ((bytesprocessed + 3) & ~3);
    srcavail -= bytesprocessed;
    BX_CIRRUS_THIS bitblt.async_xbytes += bytesprocessed;
    if (BX_CIRRUS_THIS bitblt.async_xbytes >= BX_CIRRUS_THIS bitblt.memsrc_bytesperline) {
      BX_CIRRUS_THIS bitblt.dst +=
         BX_CIRRUS_THIS bitblt.dstpitch - BX_CIRRUS_THIS bitblt.memdst_bytesperline;
      BX_CIRRUS_THIS bitblt.async_y ++;
      BX_CIRRUS_THIS bitblt.async_xbytes = 0;
      if (BX_CIRRUS_THIS bitblt.async_y >= BX_CIRRUS_THIS bitblt.bltheight) {
        total += srcavail;
        srcavail = 0;
        break;
        }
      }
    }

  BX_CIRRUS_THIS bitblt.memsrc_ptr = &BX_CIRRUS_THIS bitblt.memsrc[total];
  BX_CIRRUS_THIS redraw_area(BX_CIRRUS_THIS bitblt.pos_x, BX_CIRRUS_THIS bitblt.pos_y,
                             BX_CIRRUS_THIS bitblt.bltwidth, BX_CIRRUS_THIS bitblt.bltheight);
}

  void
bx_svga_cirrus_c::svga_simplebitblt_transp_memsrc()
{
  Bit8u color[4];
  int srcavail = BX_CIRRUS_THIS bitblt.memsrc_ptr - &BX_CIRRUS_THIS bitblt.memsrc[0];
  int bytesavail;
  int bytesprocessed;
  int x, total;
  Bit8u *srcptr = &BX_CIRRUS_THIS bitblt.memsrc[0];
  Bit8u *dst, *src;
  int srccuravail;
  unsigned bits, bitmask;
  int srcskipleft = BX_CIRRUS_THIS control.reg[0x2f] & 0x07;

  BX_DEBUG(("BLT, cpu-to-video, transparent"));

  color[0] = BX_CIRRUS_THIS control.shadow_reg1;
  color[1] = BX_CIRRUS_THIS control.reg[0x11];
  color[2] = BX_CIRRUS_THIS control.reg[0x13];
  color[3] = BX_CIRRUS_THIS control.reg[0x15];

  total = 0;
  while (1) {
    bytesavail = BX_CIRRUS_THIS bitblt.memsrc_bytesperline - BX_CIRRUS_THIS bitblt.async_xbytes;
    bytesavail = BX_MIN(bytesavail,srcavail);
    if (bytesavail <= 0)
      break;

    bytesprocessed = bytesavail;
    if (BX_CIRRUS_THIS bitblt.bltmode & CIRRUS_BLTMODE_COLOREXPAND) {
      bytesprocessed = BX_MIN(256/32,bytesavail);
      srccuravail = BX_MIN(
          bytesprocessed * 8 * BX_CIRRUS_THIS bitblt.pixelwidth,
          BX_CIRRUS_THIS bitblt.memdst_bytesperline - BX_CIRRUS_THIS bitblt.async_xbytes * 8 * BX_CIRRUS_THIS bitblt.pixelwidth);
      src = srcptr;
      dst = BX_CIRRUS_THIS bitblt.dst;
      bitmask = 0x80 >> srcskipleft;
      bits = *src++;
      for (x = 0; x < bytesprocessed * 8; x++) {
        if ((bitmask & 0xff) == 0) {
          bitmask = 0x80;
          bits = *src++;
        }
        if (bits & bitmask) {
          (*BX_CIRRUS_THIS bitblt.rop_handler)(
            dst, &color[0], 0, 0, BX_CIRRUS_THIS bitblt.pixelwidth, 1);
        }
        dst += BX_CIRRUS_THIS bitblt.pixelwidth;
        bitmask >>= 1;
      }
    } else {
      BX_ERROR(("cpu-to-video BLT: unknown bltmode %02x",BX_CIRRUS_THIS bitblt.bltmode));
      return;
    }

    BX_CIRRUS_THIS bitblt.dst += srccuravail;
    total += bytesprocessed;
    srcptr += bytesprocessed;
    srcavail -= bytesprocessed;
    BX_CIRRUS_THIS bitblt.async_xbytes += bytesprocessed;
    if (BX_CIRRUS_THIS bitblt.async_xbytes >= BX_CIRRUS_THIS bitblt.memsrc_bytesperline) {
      BX_CIRRUS_THIS bitblt.dst +=
         BX_CIRRUS_THIS bitblt.dstpitch - BX_CIRRUS_THIS bitblt.memdst_bytesperline;
      BX_CIRRUS_THIS bitblt.async_y ++;
      BX_CIRRUS_THIS bitblt.async_xbytes = 0;
      if (BX_CIRRUS_THIS bitblt.async_y >= BX_CIRRUS_THIS bitblt.bltheight) {
        total += srcavail;
        srcavail = 0;
        break;
      }
    }
  }

  BX_CIRRUS_THIS bitblt.memsrc_ptr = &BX_CIRRUS_THIS bitblt.memsrc[total];
  BX_CIRRUS_THIS redraw_area(BX_CIRRUS_THIS bitblt.pos_x, BX_CIRRUS_THIS bitblt.pos_y,
                             BX_CIRRUS_THIS bitblt.bltwidth, BX_CIRRUS_THIS bitblt.bltheight);
}

  bx_bool // true if finished, false otherwise
bx_svga_cirrus_c::svga_asyncbitblt_next()
{
  int count;
  int avail;

  if (BX_CIRRUS_THIS bitblt.bitblt_ptr == NULL) {
    BX_PANIC(("svga_asyncbitblt_next: unexpected call"));
    goto cleanup;
    }

  if (BX_CIRRUS_THIS bitblt.memdst_needed > 0) {
    BX_CIRRUS_THIS bitblt.memdst_needed -= BX_CIRRUS_THIS bitblt.memdst_ptr - &BX_CIRRUS_THIS bitblt.memdst[0];
    avail = BX_MIN(CIRRUS_BLT_CACHESIZE, BX_CIRRUS_THIS bitblt.memdst_needed);
    BX_CIRRUS_THIS bitblt.memdst_ptr = &BX_CIRRUS_THIS bitblt.memdst[0];
    BX_CIRRUS_THIS bitblt.memdst_endptr = &BX_CIRRUS_THIS bitblt.memdst[avail];

    if (BX_CIRRUS_THIS bitblt.memsrc_needed <= 0 &&
        BX_CIRRUS_THIS bitblt.memdst_needed <= 0) {
      goto cleanup;
      }
    }

  (*BX_CIRRUS_THIS bitblt.bitblt_ptr)();

  if (BX_CIRRUS_THIS bitblt.memsrc_needed > 0) {
    BX_CIRRUS_THIS bitblt.memsrc_needed -= BX_CIRRUS_THIS bitblt.memsrc_ptr - &BX_CIRRUS_THIS bitblt.memsrc[0];
    count = BX_CIRRUS_THIS bitblt.memsrc_endptr - BX_CIRRUS_THIS bitblt.memsrc_ptr;
    memmove(&BX_CIRRUS_THIS bitblt.memsrc[0], BX_CIRRUS_THIS bitblt.memsrc_ptr, count);
    avail = BX_MIN(CIRRUS_BLT_CACHESIZE, BX_CIRRUS_THIS bitblt.memsrc_needed);
    BX_CIRRUS_THIS bitblt.memsrc_ptr = &BX_CIRRUS_THIS bitblt.memsrc[count];
    BX_CIRRUS_THIS bitblt.memsrc_endptr = &BX_CIRRUS_THIS bitblt.memsrc[avail];

    if (BX_CIRRUS_THIS bitblt.memsrc_needed <= 0 &&
        BX_CIRRUS_THIS bitblt.memdst_needed <= 0) {
      goto cleanup;
      }
    }

  return false;

cleanup:
  svga_reset_bitblt();
  return true;
}

/////////////////////////////////////////////////////////////////////////
//
// Raster operations.
//
/////////////////////////////////////////////////////////////////////////

#define IMPLEMENT_FORWARD_BITBLT(name,opline) \
    static void \
  bitblt_rop_fwd_##name( \
    Bit8u *dst,const Bit8u *src, \
    int dstpitch,int srcpitch, \
    int bltwidth,int bltheight) \
  { \
    int x,y; \
    dstpitch -= bltwidth; \
    srcpitch -= bltwidth; \
    for (y = 0; y < bltheight; y++) { \
      for (x = 0; x < bltwidth; x++) { \
        opline; \
        dst++; \
        src++; \
        } \
      dst += dstpitch; \
      src += srcpitch; \
      } \
    }

#define IMPLEMENT_BACKWARD_BITBLT(name,opline) \
    static void \
  bitblt_rop_bkwd_##name( \
    Bit8u *dst,const Bit8u *src, \
    int dstpitch,int srcpitch, \
    int bltwidth,int bltheight) \
  { \
    int x,y; \
    dstpitch += bltwidth; \
    srcpitch += bltwidth; \
    for (y = 0; y < bltheight; y++) { \
      for (x = 0; x < bltwidth; x++) { \
        opline; \
        dst--; \
        src--; \
        } \
      dst += dstpitch; \
      src += srcpitch; \
      } \
    }

IMPLEMENT_FORWARD_BITBLT(0, *dst = 0)
IMPLEMENT_FORWARD_BITBLT(src_and_dst, *dst = (*src) & (*dst))
IMPLEMENT_FORWARD_BITBLT(nop, (void)0)
IMPLEMENT_FORWARD_BITBLT(src_and_notdst, *dst = (*src) & (~(*dst)))
IMPLEMENT_FORWARD_BITBLT(notdst, *dst = ~(*dst))
IMPLEMENT_FORWARD_BITBLT(src, *dst = *src)
IMPLEMENT_FORWARD_BITBLT(1, *dst = 0xff)
IMPLEMENT_FORWARD_BITBLT(notsrc_and_dst, *dst = (~(*src)) & (*dst))
IMPLEMENT_FORWARD_BITBLT(src_xor_dst, *dst = (*src) ^ (*dst))
IMPLEMENT_FORWARD_BITBLT(src_or_dst, *dst = (*src) | (*dst))
IMPLEMENT_FORWARD_BITBLT(notsrc_or_notdst, *dst = (~(*src)) | (~(*dst)))
IMPLEMENT_FORWARD_BITBLT(src_notxor_dst, *dst = ~((*src) ^ (*dst)))
IMPLEMENT_FORWARD_BITBLT(src_or_notdst, *dst = (*src) | (~(*dst)))
IMPLEMENT_FORWARD_BITBLT(notsrc, *dst = (~(*src)))
IMPLEMENT_FORWARD_BITBLT(notsrc_or_dst, *dst = (~(*src)) | (*dst))
IMPLEMENT_FORWARD_BITBLT(notsrc_and_notdst, *dst = (~(*src)) & (~(*dst)))

IMPLEMENT_BACKWARD_BITBLT(0, *dst = 0)
IMPLEMENT_BACKWARD_BITBLT(src_and_dst, *dst = (*src) & (*dst))
IMPLEMENT_BACKWARD_BITBLT(nop, (void)0)
IMPLEMENT_BACKWARD_BITBLT(src_and_notdst, *dst = (*src) & (~(*dst)))
IMPLEMENT_BACKWARD_BITBLT(notdst, *dst = ~(*dst))
IMPLEMENT_BACKWARD_BITBLT(src, *dst = *src)
IMPLEMENT_BACKWARD_BITBLT(1, *dst = 0xff)
IMPLEMENT_BACKWARD_BITBLT(notsrc_and_dst, *dst = (~(*src)) & (*dst))
IMPLEMENT_BACKWARD_BITBLT(src_xor_dst, *dst = (*src) ^ (*dst))
IMPLEMENT_BACKWARD_BITBLT(src_or_dst, *dst = (*src) | (*dst))
IMPLEMENT_BACKWARD_BITBLT(notsrc_or_notdst, *dst = (~(*src)) | (~(*dst)))
IMPLEMENT_BACKWARD_BITBLT(src_notxor_dst, *dst = ~((*src) ^ (*dst)))
IMPLEMENT_BACKWARD_BITBLT(src_or_notdst, *dst = (*src) | (~(*dst)))
IMPLEMENT_BACKWARD_BITBLT(notsrc, *dst = (~(*src)))
IMPLEMENT_BACKWARD_BITBLT(notsrc_or_dst, *dst = (~(*src)) | (*dst))
IMPLEMENT_BACKWARD_BITBLT(notsrc_and_notdst, *dst = (~(*src)) & (~(*dst)))


  bx_cirrus_bitblt_rop_t
bx_svga_cirrus_c::svga_get_fwd_rop_handler(Bit8u rop)
{
  bx_cirrus_bitblt_rop_t rop_handler = bitblt_rop_fwd_nop;

  switch (rop)
  {
    case CIRRUS_ROP_0:
      rop_handler = bitblt_rop_fwd_0;
      break;
    case CIRRUS_ROP_SRC_AND_DST:
      rop_handler = bitblt_rop_fwd_src_and_dst;
      break;
    case CIRRUS_ROP_NOP:
      rop_handler = bitblt_rop_fwd_nop;
      break;
    case CIRRUS_ROP_SRC_AND_NOTDST:
      rop_handler = bitblt_rop_fwd_src_and_notdst;
      break;
    case CIRRUS_ROP_NOTDST:
      rop_handler = bitblt_rop_fwd_notdst;
      break;
    case CIRRUS_ROP_SRC:
      rop_handler = bitblt_rop_fwd_src;
      break;
    case CIRRUS_ROP_1:
      rop_handler = bitblt_rop_fwd_1;
      break;
    case CIRRUS_ROP_NOTSRC_AND_DST:
      rop_handler = bitblt_rop_fwd_notsrc_and_dst;
      break;
    case CIRRUS_ROP_SRC_XOR_DST:
      rop_handler = bitblt_rop_fwd_src_xor_dst;
      break;
    case CIRRUS_ROP_SRC_OR_DST:
      rop_handler = bitblt_rop_fwd_src_or_dst;
      break;
    case CIRRUS_ROP_NOTSRC_OR_NOTDST:
      rop_handler = bitblt_rop_fwd_notsrc_or_notdst;
      break;
    case CIRRUS_ROP_SRC_NOTXOR_DST:
      rop_handler = bitblt_rop_fwd_src_notxor_dst;
      break;
    case CIRRUS_ROP_SRC_OR_NOTDST:
      rop_handler = bitblt_rop_fwd_src_or_notdst;
      break;
    case CIRRUS_ROP_NOTSRC:
      rop_handler = bitblt_rop_fwd_notsrc;
      break;
    case CIRRUS_ROP_NOTSRC_OR_DST:
      rop_handler = bitblt_rop_fwd_notsrc_or_dst;
      break;
    case CIRRUS_ROP_NOTSRC_AND_NOTDST:
      rop_handler = bitblt_rop_fwd_notsrc_and_notdst;
      break;
    default:
      BX_ERROR(("unknown ROP %02x",rop));
      break;
    }

  return rop_handler;
}

  bx_cirrus_bitblt_rop_t
bx_svga_cirrus_c::svga_get_bkwd_rop_handler(Bit8u rop)
{
  bx_cirrus_bitblt_rop_t rop_handler = bitblt_rop_bkwd_nop;

  switch (rop)
  {
    case CIRRUS_ROP_0:
      rop_handler = bitblt_rop_bkwd_0;
      break;
    case CIRRUS_ROP_SRC_AND_DST:
      rop_handler = bitblt_rop_bkwd_src_and_dst;
      break;
    case CIRRUS_ROP_NOP:
      rop_handler = bitblt_rop_bkwd_nop;
      break;
    case CIRRUS_ROP_SRC_AND_NOTDST:
      rop_handler = bitblt_rop_bkwd_src_and_notdst;
      break;
    case CIRRUS_ROP_NOTDST:
      rop_handler = bitblt_rop_bkwd_notdst;
      break;
    case CIRRUS_ROP_SRC:
      rop_handler = bitblt_rop_bkwd_src;
      break;
    case CIRRUS_ROP_1:
      rop_handler = bitblt_rop_bkwd_1;
      break;
    case CIRRUS_ROP_NOTSRC_AND_DST:
      rop_handler = bitblt_rop_bkwd_notsrc_and_dst;
      break;
    case CIRRUS_ROP_SRC_XOR_DST:
      rop_handler = bitblt_rop_bkwd_src_xor_dst;
      break;
    case CIRRUS_ROP_SRC_OR_DST:
      rop_handler = bitblt_rop_bkwd_src_or_dst;
      break;
    case CIRRUS_ROP_NOTSRC_OR_NOTDST:
      rop_handler = bitblt_rop_bkwd_notsrc_or_notdst;
      break;
    case CIRRUS_ROP_SRC_NOTXOR_DST:
      rop_handler = bitblt_rop_bkwd_src_notxor_dst;
      break;
    case CIRRUS_ROP_SRC_OR_NOTDST:
      rop_handler = bitblt_rop_bkwd_src_or_notdst;
      break;
    case CIRRUS_ROP_NOTSRC:
      rop_handler = bitblt_rop_bkwd_notsrc;
      break;
    case CIRRUS_ROP_NOTSRC_OR_DST:
      rop_handler = bitblt_rop_bkwd_notsrc_or_dst;
      break;
    case CIRRUS_ROP_NOTSRC_AND_NOTDST:
      rop_handler = bitblt_rop_bkwd_notsrc_and_notdst;
      break;
    default:
      BX_ERROR(("unknown ROP %02x",rop));
      break;
    }

  return rop_handler;
}


#endif // BX_SUPPORT_CLGD54XX