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#define HD_PORT_DATA         0x1f0
#define HD_PORT_ERROR        0x1f1
#define HD_PORT_SECT_COUNT   0x1f2
#define HD_PORT_SECT_NUM     0x1f3
#define HD_PORT_CYL_LOW      0x1f4
#define HD_PORT_CYL_HIGH     0x1f5
#define HD_PORT_DRV_HEAD     0x1f6
#define HD_PORT_STATUS       0x1f7
#define HD_PORT_COMMAND      0x1f7

#define HD_READ              0x20
#define HD_WRITE             0x30

#define inb(port) (__extension__({	\
unsigned char __res;	\
__asm__ ("inb	%%dx,	%%al\n\t"	\
					 :"=a"(__res)	\
					 :"dx"(port));	\
__res;	\
}))

#define outb(value, port) __asm__ (	\
"outb	%%al,	%%dx\n\t"::"al"(value), "dx"(port))

#define insl(port, buf, nr) \
__asm__ ("cld;rep;insl\n\t"	\
::"d"(port), "D"(buf), "c"(nr))

#define outsl(buf, nr, port) \
__asm__ ("cld;rep;outsl\n\t"	\
::"d"(port), "S" (buf), "c" (nr))

void Read(unsigned int lba, unsigned int sects_to_access, void *buf)
{
	/* lba to chs */
	/* cylinder = LBA / (heads_per_cylinder * sectors_per_track)
	   temp = LBA % (heads_per_cylinder * sectors_per_track)
	   head = temp / sectors_per_track
	   sector = temp % sectors_per_track + 1 */
	unsigned int cyl = lba/(HD0.head * HD0.sect);
	unsigned int head = (lba%(HD0.head*HD0.sect))/HD0.sect;
	unsigned int sect = (lba%(HD0.head*HD0.sect))%HD0.sect+1;

	while ((inb(HD_PORT_STATUS)&0xc0)!=0x40)
		;

	outb(sects_to_access, HD_PORT_SECT_COUNT);
	outb(sect, HD_PORT_SECT_NUM);
	outb(cyl, HD_PORT_CYL_LOW);
	outb(cyl>>8, HD_PORT_CYL_HIGH);
	outb(0xa0|head, HD_PORT_DRV_HEAD);
	outb(HD_READ, HD_PORT_COMMAND);

	while (! (inb(HD_PORT_STATUS)&0x8))
		;

	insl(HD_PORT_DATA, buf, sects_to_access<<7);
}

void Write(unsigned int lba, unsigned int sects_to_access, void *buf)
{
	/* lba to chs */
	/* cylinder = LBA / (heads_per_cylinder * sectors_per_track)
	   temp = LBA % (heads_per_cylinder * sectors_per_track)
	   head = temp / sectors_per_track
	   sector = temp % sectors_per_track + 1 */
	unsigned int cyl = lba/(HD0.head * HD0.sect);
	unsigned int head = (lba%(HD0.head*HD0.sect))/HD0.sect;
	unsigned int sect = (lba%(HD0.head*HD0.sect))%HD0.sect+1;

	while ((inb(HD_PORT_STATUS)&0xc0)!=0x40)
		;

	outb(sects_to_access, HD_PORT_SECT_COUNT);
	outb(sect, HD_PORT_SECT_NUM);
	outb(cyl, HD_PORT_CYL_LOW);
	outb(cyl>>8, HD_PORT_CYL_HIGH);
	outb(0xa0|head, HD_PORT_DRV_HEAD);
	outb(HD_WRITE, HD_PORT_COMMAND);

	while (! (inb(HD_PORT_STATUS)&0x8))
		;

	outsl(buf, sects_to_access<<7, HD_PORT_DATA);
}

Code: Select all

char buffer[512];
	memset(buffer, 'a', 512);
	buffer[511] = '\0';

	Video_PutString("Empty buffer:");
	Video_PutString(buffer);
	Video_PutString("\n");
	HardDrive::Write(45, 1, buffer);

	memset(buffer, 'b', 512);
	buffer[511] = '\0';
	
	HardDrive::Read(45, 1, buffer);
	buffer[511] = '\0';
	Video_PutString("Sector buffer:");
	Video_PutString(buffer);
	Video_PutString("\n");