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#define ATA_DATA_REGISTER 0x1F0
#define ATA_ERROR_REGISTER 0x1F1
#define ATA_SECTORS_REGISTER 0x1F2
#define ATA_SECTOR_NUMBER 0x1F3
#define ATA_CYLINDERS_LOW 0x1F4
#define ATA_CYLINDERS_HIGH 0x1F5
#define ATA_DRIVE_HEAD 0x1F6
#define ATA_STATUS_REGISTER 0x1F7
#define ATA_COMMAND_REGISTER 0x1F7

#define ATA_FORMAT_TRACK 0x50
#define ATA_READ_SECTOR_RETRY 0x20
#define ATA_READ_SECTOR 0x21
#define ATA_READ_LONG_RETRY 0x22
#define ATA_READ_LONG 0x23
#define ATA_WRITE_SECTOR_RETRY 0x30
#define ATA_WRITE_SECTOR 0x31
#define ATA_WRITE_LONG_RETRY 0x32
#define ATA_WRITE_LONG 0x33

#define ATA_DRIVE_BUSY 0x80
#define ATA_DRIVE_READY 0x40
#define ATA_WRITE_FAULT 0x20
#define ATA_SEEK_COMPLETE 0x10
#define ATA_BUFFER_SECTOR 0x08
#define ATA_DATA_CORRECTION 0x04
#define ATA_INDEX 0x02
#define ATA_ERROR 0x01

struct ATA_SECTOR get_sector(void);
struct ATA_SECTOR readATAsector(unsigned char drive,unsigned char head,unsigned char cylinders_low,unsigned char cylinders_high,unsigned char sector)
{
	unsigned char drive_head;
	struct ATA_SECTOR s;

	if(drive==0)
	{
		drive_head=0xA0;
	}
	else
	{
		drive_head=0xB0;
	}

	while(1)
	{
		if((inportb(ATA_STATUS_REGISTER)&ATA_DRIVE_BUSY)!=ATA_DRIVE_BUSY) break;
	}

	drive_head=drive_head|head;
	outportb(ATA_DRIVE_HEAD,drive_head);

	outportb(ATA_SECTORS_REGISTER,1);
	outportb(ATA_SECTOR_NUMBER,sector);
	outportb(ATA_CYLINDERS_LOW,cylinders_low);
	outportb(ATA_CYLINDERS_HIGH,cylinders_high);
	outportb(ATA_COMMAND_REGISTER,ATA_READ_SECTOR_RETRY);


	s=get_sector();
	s.drive=drive;
	s.head=head;
	s.cylinders_high=cylinders_high;
	s.cylinders_low=cylinders_low;
	s.sector=sector;
	return s;
}

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struct ATA_SECTOR get_sector(void)
{
	while(sector.read==0);
	sector.read=0;
	return sector;
}

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struct ATA_SECTOR
{
	unsigned char data;
	unsigned char sector;
	unsigned char cylinders_high;
	unsigned char cylinders_low;
	unsigned char drive;
	unsigned char head;
	unsigned char read;
};

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sector.data=inportb(0x1F0);
sector.read=1;

if((inportb(0x1F7)&0x01)==0x01) sector.data=-1;

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void _main(void* mbd,unsigned int magic)
{
	struct ATA_SECTOR s;
	struct ATA_SECTOR a;

	kinit();

	Printf("hello world!\n");
	s=readATAsector(0,0,69,69,1);
	if(s.data!=-1)
	{
		putchar(s.data);
	}
	else
	{
		Printf("\nATA error\n");
	}

	a=readATAsector(0,0,69,69,1);
	if(a.data!=-1)
	{
		putchar(a.data);
	}
	else
	{
		Printf("\nATA error\n");
	}	
	for(;;);
}

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    .StartReadingData:


      ; When the device is ready to transfer the data, it will clear BSY and set DRQ
      MOV     EDX , EBX
      ADD     EDX , IDE_PORT_OFFSET_STATUS
      MOV     ECX , IDE_TYPICAL_TIMEOUT
      XOR     EAX , EAX
      .WaitForBSYAndDRQ:
        NOP
        IN      AL , DX
        AND     EAX , (IDE_STATUSREG_BSY | IDE_STATUSREG_DRQ)
        XOR     EAX , IDE_STATUSREG_DRQ
        JZ      .PrepareToSenseInterrupt
        DEC     ECX
        JNZ     .WaitForBSYAndDRQ
        JMP     .Failure



      .PrepareToSenseInterrupt:
        MOV     EAX , IRQ_PULSE_IRQ14
        CMP     EBX , PIDEC_PORT_BASE
        JE      .SenseInterrupt
        MOV     EAX , IRQ_PULSE_IRQ15
        .SenseInterrupt:
          INVOKE  __WaitForIRQPulse, EAX



      .CheckStatusRegister1:
        ; EDX = Status Register's port address
        IN      AL , DX


      .ReadData:
        ; EDI = [Buffer]
        CLD
        MOV     EDX , EBX
        ADD     EDX , IDE_PORT_OFFSET_DATA
        MOV     ECX , 512 / 2 ; We are reading 2 bytes at a time and one sector after the other
        REP     INSW




      DEC     ESI
      JNZ     .StartReadingData




    ; Now that the data is read, we should first read the Alternate Status Register and ignore the result
    ; EBX = The base port address of the selected controller
    .ReadAlternateStatusRegister:
      MOV     EDX , IDEC_PORT_ALTERNATESTATUS
      IN      AL , DX
      TIMES   0x04 NOP




    ; Reading the Status Register is also recommended by ATA-4 specifications
    .ReadStatusRegister:
      ; EBX = The base port address of the selected controller
      MOV     EDX , EBX
      ADD     EDX , IDE_PORT_OFFSET_STATUS
      IN      AL , DX
      TIMES   0x04 NOP