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Code: Select all

#ifndef DISK_H_INCLUDED
#include "ata.h"
#define DISK_H_INCLUDED
#endif

BOOL ata_wait_until_not_busy(uint32_t timeout_ms)
{
	uint8_t status = inportb(0x1F7);
	uint32_t startTick = get_tick_count();
	while(status & 0x88) //BSY and DRQ must be clear
	{
		if(get_tick_count() > startTick + timeout_ms)
			return FALSE;
		status = inportb(0x1F7);
	}
	return TRUE;
}

void ata_send_command(unsigned char command)
{
	outportb(0x1F7, command);
}

void ata_select_drive(uint8_t drive)
{
	uint8_t buf = inportb(0x1F6);
	if(drive)
		buf |= 0x10; //set bit 4
	
	buf = 0;
	
	outportb(0x1F6, buf);
}

void ata_interrupt_enable(BOOL enable)
{
	uint8_t buf = 0;
	if(enable)
		buf |= 2;
	
	outportb(0x3F6, buf);
}

BOOL ata_read_lba28(uint32_t LBA, uint8_t sectorCount, void* dest)
{
	if(!ata_wait_until_not_busy(1000))
		return FALSE;
	
	outportb(0x1F2, sectorCount); //sector count
	outportb(0x1F3, LBA & 0xFF); //LBA low byte
	outportb(0x1F4, (LBA >> 8) & 0xFF); //LBA mid byte
	outportb(0x1F5, (LBA >> 16) & 0xFF); //LBA high byte
	outportb(0x1F6, (LBA >> 24) & 0x0F); //bits 24-28 of LBA
	ata_select_drive(0);
	ata_interrupt_enable(FALSE);
	ata_send_command(0x20); //read sectors with retry
	
	uint8_t status = 0;
	
	for(unsigned int i=0;i<4;i++)
	{
		status = inportb(0x1F7);
		if(!(status & 0x80)) //BSY bit clear
		{
			if(status & 0x8) //DRQ bit set
				goto data_ready;
		}
	}
	
	while(1)
	{
		status = inportb(0x1F7);
		if(status & 0x80) //BSY set
			continue;
		else
			break;
		
		if(status & 0x1) //ERR set
			return FALSE;
		
		if(status & 0x20) //DF set
			return FALSE;
	}
	
	
data_ready: ;
	
	uint16_t* p = (uint16_t*)dest;
	
	for(unsigned int i=0;i<sectorCount;i++)
	{
		for(unsigned int i=0;i<256;i++)
		{
			*p = inportw(0x1F0);
			p++;
		}
		
		inportb(0x1F7);
		inportb(0x1F7);
		inportb(0x1F7);
		inportb(0x1F7);//400ns delay
		
		while(1)
		{
			status = inportb(0x1F7);
			if(status & 0x80) //BSY set
				continue;
			else
				break;
			
			if(status & 0x1) //ERR set
				return FALSE;
			
			if(status & 0x20) //DF set
				return FALSE;
		}
	}
	
	return TRUE;
}

Code: Select all

#ifndef STDINC_H_INCLUDED
#include "stdinc.h"
#define STDINC_H_INCLUDED
#endif

#ifndef TIMER_H_INCLUDED
#include "timer.h"
#define TIMER_H_INCLUDED
#endif

BOOL ata_wait_until_not_busy(uint32_t timeout_ms);
void ata_send_command(unsigned char command);
void ata_select_drive(uint8_t drive);
void ata_interrupt_enable(BOOL enable);
BOOL ata_read_lba28(uint32_t LBA, uint8_t sectorCount, void* dest);

Code: Select all

if(ata_read_lba28(0, 1, (void*)0x00140000))
		print_string("success");
[code]
it prints "success". However if I do a memory dump, the bootsector (what I am reading from the disk) is nowhere to be found.

I am new to making drivers, so the code is probably full of errors....

I will do more debugging, but there might be a blatent error in my driver, so I thought I might as well post it on here.

Also, some people may be offended by that [b]goto[/b], IDGAF.