OSDev

bool Detect()
{
    KeWaitForSymbol(SmPCI_Ready);

     byte Bus;
  byte Device;
       byte Function;
     if (!GetPCIDeviceByID(0x5333, 0x8811, Bus, Device, Function))
          return false;

 dword RegVal = GetPCIDeviceReg(Bus, Device, Function, 0x10);
   m_FBBase = RegVal & 0xFFFFF000;
        return true;
}

void InitS3V()
{
    static byte ActlRegs[] = {0x01, 0x00, 0x0F, 0x00, 0x00};
       static byte SeqRegs[] =  {0x03, 0x01, 0x0F, 0x00, 0x06};
   static byte GraphRegs[] =
      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0x0F, 0xFF};

   // Reset Attribute Controller Flip-Flop
    KeInPortByte(0x3DA);
   // Set Attribute Controller Regs
   InitRegs(0x3C0, ActlRegs, 0x10, 5);
        // Set Sequencer Regs
  InitRegs(0x3C4, SeqRegs, 0, 5);
    // Set Graphics Regs
   InitRegs(0x3CE, GraphRegs, 0, 9);

     // Unlock Sequencer PLL Registers
  KeOutPortWord(0x3C4, 0x0608);
      // Unlock CRTC Registers 1
 KeOutPortWord(0x3D4, 0x4838);
      // Unlock CRTC Registers 2
 KeOutPortWord(0x3D4, 0xA539);

 // Linear Address Window Control Register
      byte CR58 = ReadReg(0x3D4, 0x58);
      // Enable Linear Addressing
    // Set Linear Address Window Size = 2 MB
   WriteReg(0x3D4, 0x58, (CR58 & 0xFC) | 0x12);

      // Extended Mode Register
      byte CR43 = ReadReg(0x3D4, 0x43);
      // Disable 64K Color Mode
  WriteReg(0x3D4, 0x43, CR43 & 0xF7);

       // System Configuration Register
       byte CR40 = ReadReg(0x3D4, 0x40);
      // Enable Enhanced Register Access
 WriteReg(0x3D4, 0x40, CR40 | 0x01);

       // Advanced Function Control Register
      // Enable Enhanced Functions
   KeOutPortByte(0x4AE8, 0x03);

  // Vertical Retrace End Register
   byte CR11 = ReadReg(0x3D4, 0x11);
      // Disable CRTC Registers Protect
  WriteReg(0x3D4, 0x11, CR11 & 0x7F);

       static byte CRTRegs[] =
   {
          0x7B, 0x63, 0x63, 0x80, 0x67, 0x10, 0x6F, 0xF0,
                0x00, 0x60, 0x00, 0x00, 0x00, 0x00, 0xFF, 0x00,
                0x58, 0x8A, 0x57, 0x90, 0x00, 0x57, 0x00, 0xE3,
                0xFF
       };

        // Set CRTC Regs
       InitRegs(0x3D4, CRTRegs, 0, 25);

      // Set Logical Screen Width Bits (8-9)
     KeOutPortWord(0x3D4, 0x1051);

 // Miscellaneous 1 Register
    // Enable Alternate Refresh Count Control
      // Enable 256 Color Enhanced Mode
      KeOutPortWord(0x3D4, 0x153A);

 // Memory Configuration Register
       // Enable Base Address Offset
      // Use Enhanced Mode Memory Mapping
    KeOutPortWord(0x3D4, 0x0931);

 // Sequencer: 32 BPP (?)
       KeOutPortWord(0x3C4, 0x4018);

 // Sequencer: (?)
      byte SR15 = ReadReg(0x3C4, 0x15);
      WriteReg(0x3C4, 0x15, SR15 & 0xAF);

       // Extended Miscellaneous Control Register 2
   byte CR67 = ReadReg(0x3D4, 0x67);
      // Set 32 BPP Pixel Format
     WriteReg(0x3D4, 0x67, (CR67 & 0x0F) | 0xD0);
}

byte ReadReg(dword IndexPort, dword RegIndex)
{
        KeOutPortByte(IndexPort, RegIndex);
        return KeInPortByte(IndexPort + 1);
}

void WriteReg(dword IndexPort, dword RegIndex, byte RegValue)
{
     KeOutPortWord(IndexPort, (RegValue << 8) | RegIndex);
}

void InitRegs(word IndexPort, byte* Data, dword BaseReg, dword Size)
{
        for (dword i = 0; i < Size; i++)
       {
          word W = (Data[i] << 8) | (BaseReg + i);
           KeOutPortWord(IndexPort, W);
       }
}