text: // Video Bios Extensions handlers
  //
  // Copyright (C) 2012  Kevin O'Connor <kevin@koconnor.net>
  // Copyright (C) 2011  Julian Pidancet <julian.pidancet@citrix.com>
  // Copyright (C) 2001-2008 the LGPL VGABios developers Team
  //
  // This file may be distributed under the terms of the GNU LGPLv3 license.
  
  #include "biosvar.h" // GET_GLOBAL
  #include "bregs.h" // struct bregs
  #include "config.h" // CONFIG_*
  #include "output.h" // dprintf
  #include "std/vbe.h" // struct vbe_info
  #include "string.h" // memset_far
  #include "vgabios.h" // get_current_mode
  #include "vgahw.h" // vgahw_set_mode
  #include "vgautil.h" // handle_104f
  
  #define VBE_OEM_STRING "SeaBIOS VBE(C) 2011"
  #define VBE_VENDOR_STRING "SeaBIOS Developers"
  #define VBE_PRODUCT_STRING "SeaBIOS VBE Adapter"
  #define VBE_REVISION_STRING "Rev. 1"
  
  u32 VBE_total_memory VAR16 = 256 * 1024;
  u32 VBE_capabilities VAR16;
  u32 VBE_framebuffer VAR16;
  u16 VBE_win_granularity VAR16;
  u8 VBE_edid[256] VAR16;
  
  static void
  vbe_104f00(struct bregs *regs)
  {
      u16 seg = regs->es;
      struct vbe_info *info = (void*)(regs->di+0);
  
      if (GET_FARVAR(seg, info->signature) == VBE2_SIGNATURE) {
          dprintf(4, "Get VBE Controller: VBE2 Signature found\n");
      } else if (GET_FARVAR(seg, info->signature) == VESA_SIGNATURE) {
          dprintf(4, "Get VBE Controller: VESA Signature found\n");
      } else {
          dprintf(4, "Get VBE Controller: Invalid Signature\n");
      }
  
      memset_far(seg, info, 0, sizeof(*info));
  
      SET_FARVAR(seg, info->signature, VESA_SIGNATURE);
  
      SET_FARVAR(seg, info->version, 0x0300);
  
      SET_FARVAR(seg, info->oem_string,
              SEGOFF(get_global_seg(), (u32)VBE_OEM_STRING));
      SET_FARVAR(seg, info->capabilities, GET_GLOBAL(VBE_capabilities));
  
      /* We generate our mode list in the reserved field of the info block */
      u16 *destmode = (void*)info->reserved;
      SET_FARVAR(seg, info->video_mode, SEGOFF(seg, (u32)destmode));
  
      /* Total memory (in 64k blocks) */
      SET_FARVAR(seg, info->total_memory
                 , GET_GLOBAL(VBE_total_memory) / (64*1024));
  
      SET_FARVAR(seg, info->oem_vendor_string,
              SEGOFF(get_global_seg(), (u32)VBE_VENDOR_STRING));
      SET_FARVAR(seg, info->oem_product_string,
              SEGOFF(get_global_seg(), (u32)VBE_PRODUCT_STRING));
      SET_FARVAR(seg, info->oem_revision_string,
              SEGOFF(get_global_seg(), (u32)VBE_REVISION_STRING));
  
      /* Fill list of modes */
      u16 *last = (void*)&info->reserved[sizeof(info->reserved)];
      vgahw_list_modes(seg, destmode, last - 1);
  
      regs->ax = 0x004f;
  }
  
  static void
  vbe_104f01(struct bregs *regs)
  {
      u16 seg = regs->es;
      struct vbe_mode_info *info = (void*)(regs->di+0);
      u16 mode = regs->cx;
  
      dprintf(1, "VBE mode info request: %x\n", mode);
  
      struct vgamode_s *vmode_g = vgahw_find_mode(mode & ~MF_VBEFLAGS);
      if (! vmode_g) {
          dprintf(1, "VBE mode %x not found\n", mode);
          regs->ax = 0x014f;
          return;
      }
  
      memset_far(seg, info, 0, sizeof(*info));
  
      // Basic information about video controller.
      u32 win_granularity = GET_GLOBAL(VBE_win_granularity);
      SET_FARVAR(seg, info->winA_attributes,
                 (win_granularity ? VBE_WINDOW_ATTRIBUTE_RELOCATABLE : 0) |
                 VBE_WINDOW_ATTRIBUTE_READABLE |
                 VBE_WINDOW_ATTRIBUTE_WRITEABLE);
      SET_FARVAR(seg, info->winB_attributes, 0);
      SET_FARVAR(seg, info->win_granularity, win_granularity);
      SET_FARVAR(seg, info->win_size, 64); /* Bank size 64K */
      SET_FARVAR(seg, info->winA_seg, GET_GLOBAL(vmode_g->sstart));
      SET_FARVAR(seg, info->winB_seg, 0x0);
      extern void entry_104f05(void);
      SET_FARVAR(seg, info->win_func_ptr
                 , SEGOFF(get_global_seg(), (u32)entry_104f05));
      // Basic information about mode.
      int width = GET_GLOBAL(vmode_g->width);
      int height = GET_GLOBAL(vmode_g->height);
      int linesize = vgahw_get_linesize(vmode_g);
      SET_FARVAR(seg, info->bytes_per_scanline, linesize);
      SET_FARVAR(seg, info->xres, width);
      SET_FARVAR(seg, info->yres, height);
      SET_FARVAR(seg, info->xcharsize, GET_GLOBAL(vmode_g->cwidth));
      SET_FARVAR(seg, info->ycharsize, GET_GLOBAL(vmode_g->cheight));
      int depth = GET_GLOBAL(vmode_g->depth);
      SET_FARVAR(seg, info->bits_per_pixel, depth);
      u8 memmodel = GET_GLOBAL(vmode_g->memmodel);
      SET_FARVAR(seg, info->mem_model, memmodel);
      SET_FARVAR(seg, info->reserved0, 1);
  
      // Mode specific info.
      u16 mode_attr = VBE_MODE_ATTRIBUTE_SUPPORTED |
                      VBE_MODE_ATTRIBUTE_EXTENDED_INFORMATION_AVAILABLE |
                      VBE_MODE_ATTRIBUTE_COLOR_MODE |
                      VBE_MODE_ATTRIBUTE_GRAPHICS_MODE |
                      VBE_MODE_ATTRIBUTE_NOT_VGA_COMPATIBLE;
      u32 framebuffer = 0;
      int planes = 1, banks = 1;
      u32 pages = GET_GLOBAL(VBE_total_memory) / ALIGN(height * linesize, 64*1024);
      switch (memmodel) {
      case MM_TEXT:
          mode_attr &= ~VBE_MODE_ATTRIBUTE_GRAPHICS_MODE;
          mode_attr |= VBE_MODE_ATTRIBUTE_TTY_BIOS_SUPPORT;
          if (GET_GLOBAL(vmode_g->sstart) == SEG_MTEXT)
              mode_attr &= ~VBE_MODE_ATTRIBUTE_COLOR_MODE;
          pages = 1;
          break;
      case MM_CGA:
          pages = 1;
          banks = 2;
          SET_FARVAR(seg, info->bank_size, 8);
          break;
      case MM_PLANAR:
          planes = 4;
          pages /= 4;
          break;
      default:
          framebuffer = GET_GLOBAL(VBE_framebuffer);
          if (framebuffer)
              mode_attr |= VBE_MODE_ATTRIBUTE_LINEAR_FRAME_BUFFER_MODE;
          break;
      }
      if (pages > 128)
          pages = 128;
      if (pages < 2)
          pages++;
      SET_FARVAR(seg, info->mode_attributes, mode_attr);
      SET_FARVAR(seg, info->planes, planes);
      SET_FARVAR(seg, info->pages, pages - 1);
      SET_FARVAR(seg, info->banks, banks);
  
      // Pixel color breakdown
      u8 r_size, r_pos, g_size, g_pos, b_size, b_pos, a_size, a_pos;
      switch (depth) {
      case 15: r_size = 5; r_pos = 10; g_size = 5; g_pos = 5;
               b_size = 5; b_pos = 0; a_size = 1; a_pos = 15; break;
      case 16: r_size = 5; r_pos = 11; g_size = 6; g_pos = 5;
               b_size = 5; b_pos = 0; a_size = 0; a_pos = 0; break;
      case 24: r_size = 8; r_pos = 16; g_size = 8; g_pos = 8;
               b_size = 8; b_pos = 0; a_size = 0; a_pos = 0; break;
      case 32: r_size = 8; r_pos = 16; g_size = 8; g_pos = 8;
               b_size = 8; b_pos = 0; a_size = 8; a_pos = 24;
               SET_FARVAR(seg, info->directcolor_info,
                          VBE_DIRECTCOLOR_RESERVED_BITS_AVAILABLE);
               break;
      default: r_size = 0; r_pos = 0; g_size = 0; g_pos = 0;
               b_size = 0; b_pos = 0; a_size = 0; a_pos = 0; break;
      }
      SET_FARVAR(seg, info->red_size, r_size);
      SET_FARVAR(seg, info->red_pos, r_pos);
      SET_FARVAR(seg, info->green_size, g_size);
      SET_FARVAR(seg, info->green_pos, g_pos);
      SET_FARVAR(seg, info->blue_size, b_size);
      SET_FARVAR(seg, info->blue_pos, b_pos);
      SET_FARVAR(seg, info->alpha_size, a_size);
      SET_FARVAR(seg, info->alpha_pos, a_pos);
  
      // Linear framebuffer info.
      if (framebuffer) {
          SET_FARVAR(seg, info->phys_base, framebuffer);
  
          SET_FARVAR(seg, info->reserved1, 0);
          SET_FARVAR(seg, info->reserved2, 0);
          SET_FARVAR(seg, info->linear_bytes_per_scanline, linesize);
          SET_FARVAR(seg, info->linear_pages, 0);
          SET_FARVAR(seg, info->linear_red_size, r_size);
          SET_FARVAR(seg, info->linear_red_pos, r_pos);
          SET_FARVAR(seg, info->linear_green_size, g_size);
          SET_FARVAR(seg, info->linear_green_pos, g_pos);
          SET_FARVAR(seg, info->linear_blue_size, b_size);
          SET_FARVAR(seg, info->linear_blue_pos, b_pos);
          SET_FARVAR(seg, info->linear_alpha_size, a_size);
          SET_FARVAR(seg, info->linear_alpha_pos, a_pos);
      }
  
      regs->ax = 0x004f;
  }
  
  static void
  vbe_104f02(struct bregs *regs)
  {
      dprintf(1, "VBE mode set: %x\n", regs->bx);
  
      int mode = regs->bx & ~MF_VBEFLAGS;
      int flags = regs->bx & MF_VBEFLAGS;
      int ret = vga_set_mode(mode, flags);
  
      regs->ah = ret;
      regs->al = 0x4f;
  }
  
  static void
  vbe_104f03(struct bregs *regs)
  {
      regs->bx = GET_BDA_EXT(vbe_mode);
      dprintf(1, "VBE current mode=%x\n", regs->bx);
      regs->ax = 0x004f;
  }
  
  static void
  vbe_104f04(struct bregs *regs)
  {
      u16 seg = regs->es;
      void *data = (void*)(regs->bx+0);
      u16 states = regs->cx;
      u8 cmd = regs->dl;
      if (states & ~0x0f || cmd > 2)
          goto fail;
      int ret = vgahw_save_restore(states | (cmd<<8), seg, data);
      if (ret < 0)
          goto fail;
      if (cmd == 0)
          regs->bx = ret / 64;
      regs->ax = 0x004f;
      return;
  fail:
      regs->ax = 0x014f;
  }
  
  void VISIBLE16
  vbe_104f05(struct bregs *regs)
  {
      if (regs->bh > 1 || regs->bl > 1)
          goto fail;
      if (GET_BDA_EXT(vbe_mode) & MF_LINEARFB) {
          regs->ah = VBE_RETURN_STATUS_INVALID;
          return;
      }
      struct vgamode_s *vmode_g = get_current_mode();
      if (! vmode_g)
          goto fail;
      if (regs->bh) {
          int ret = vgahw_get_window(vmode_g, regs->bl);
          if (ret < 0)
              goto fail;
          regs->dx = ret;
          regs->ax = 0x004f;
          return;
      }
      int ret = vgahw_set_window(vmode_g, regs->bl, regs->dx);
      if (ret)
          goto fail;
      regs->ax = 0x004f;
      return;
  fail:
      regs->ax = 0x014f;
  }
  
  static void
  vbe_104f06(struct bregs *regs)
  {
      if (regs->bl > 0x02)
          goto fail;
      struct vgamode_s *vmode_g = get_current_mode();
      if (! vmode_g)
          goto fail;
      int bpp = vga_bpp(vmode_g);
  
      if (regs->bl == 0x00) {
          int ret = vgahw_set_linelength(vmode_g, DIV_ROUND_UP(regs->cx * bpp, 8));
          if (ret)
              goto fail;
      } else if (regs->bl == 0x02) {
          int ret = vgahw_set_linelength(vmode_g, regs->cx);
          if (ret)
              goto fail;
      }
      int linelength = vgahw_get_linelength(vmode_g);
      if (linelength < 0)
          goto fail;
  
      regs->bx = linelength;
      regs->cx = (linelength * 8) / bpp;
      regs->dx = GET_GLOBAL(VBE_total_memory) / linelength;
      regs->ax = 0x004f;
      return;
  fail:
      regs->ax = 0x014f;
  }
  
  static void
  vbe_104f07(struct bregs *regs)
  {
      struct vgamode_s *vmode_g = get_current_mode();
      if (! vmode_g)
          goto fail;
      int bpp = vga_bpp(vmode_g);
      int linelength = vgahw_get_linelength(vmode_g);
      if (linelength < 0)
          goto fail;
  
      int ret;
      switch (regs->bl) {
      case 0x80:
      case 0x00:
          ret = vgahw_set_displaystart(
              vmode_g, DIV_ROUND_UP(regs->cx * bpp, 8) + linelength * regs->dx);
          if (ret)
              goto fail;
          break;
      case 0x01:
          ret = vgahw_get_displaystart(vmode_g);
          if (ret < 0)
              goto fail;
          regs->dx = ret / linelength;
          regs->cx = (ret % linelength) * 8 / bpp;
          break;
      default:
          goto fail;
      }
      regs->ax = 0x004f;
      return;
  fail:
      regs->ax = 0x014f;
  }
  
  static void
  vbe_104f08(struct bregs *regs)
  {
      struct vgamode_s *vmode_g = get_current_mode();
      if (! vmode_g)
          goto fail;
      u8 memmodel = GET_GLOBAL(vmode_g->memmodel);
      if (memmodel == MM_DIRECT || memmodel == MM_YUV) {
          regs->ax = 0x034f;
          return;
      }
      if (regs->bl > 1)
          goto fail;
      if (regs->bl == 0) {
          int ret = vgahw_set_dacformat(vmode_g, regs->bh);
          if (ret < 0)
              goto fail;
      }
      int ret = vgahw_get_dacformat(vmode_g);
      if (ret < 0)
          goto fail;
      regs->bh = ret;
      regs->ax = 0x004f;
      return;
  fail:
      regs->ax = 0x014f;
  }
  
  static void
  vbe_104f0a(struct bregs *regs)
  {
      debug_stub(regs);
      regs->ax = 0x0100;
  }
  
  static void
  vbe_104f10(struct bregs *regs)
  {
      switch (regs->bl) {
      case 0x00:
          regs->bx = 0x0f30;
          break;
      case 0x01:
          MASK_BDA_EXT(flags, BF_PM_MASK, regs->bh & BF_PM_MASK);
          break;
      case 0x02:
          regs->bh = GET_BDA_EXT(flags) & BF_PM_MASK;
          break;
      default:
          regs->ax = 0x014f;
          return;
      }
      regs->ax = 0x004f;
  }
  
  static void
  vbe_104f15(struct bregs *regs)
  {
      int offset;
  
      switch (regs->bl) {
      case 0x00:
          if (GET_GLOBAL(VBE_edid[0]) != 0x00 ||
              GET_GLOBAL(VBE_edid[1]) != 0xff)
              goto err;
          regs->bx = 0x0103;
          break;
      case 0x01:
          offset = regs->dx * 128;
          if (offset >= sizeof(VBE_edid))
              goto err;
          memcpy_far(regs->es, (void*)(regs->di+0),
                     get_global_seg(), VBE_edid + offset,
                     128);
          break;
      err:
      default:
          regs->ax = 0x014f;
          return;
      }
      regs->ax = 0x004f;
  }
  
  static void
  vbe_104fXX(struct bregs *regs)
  {
      debug_stub(regs);
      regs->ax = 0x0100;
  }
  
  void noinline
  handle_104f(struct bregs *regs)
  {
      if (!CONFIG_VGA_VBE) {
          vbe_104fXX(regs);
          return;
      }
  
      switch (regs->al) {
      case 0x00: vbe_104f00(regs); break;
      case 0x01: vbe_104f01(regs); break;
      case 0x02: vbe_104f02(regs); break;
      case 0x03: vbe_104f03(regs); break;
      case 0x04: vbe_104f04(regs); break;
      case 0x05: vbe_104f05(regs); break;
      case 0x06: vbe_104f06(regs); break;
      case 0x07: vbe_104f07(regs); break;
      case 0x08: vbe_104f08(regs); break;
      case 0x0a: vbe_104f0a(regs); break;
      case 0x10: vbe_104f10(regs); break;
      case 0x15: vbe_104f15(regs); break;
      default:   vbe_104fXX(regs); break;
      }
  }
  