k-tana-zero/k/atapi.c

76 lines
1.6 KiB
C

#include <k/atapi.h>
#include <string.h>
#include "atapi.h"
#include "io.h"
static struct atapi_drive drives[4] = { 0 };
static void select_drive(uint16_t bus, uint8_t slave)
{
outb(ATA_REG_DRIVE(bus), slave);
}
static void busy_wait(uint16_t drive)
{
int res = 0;
while (res & BSY)
res = inb(ATA_REG_STATUS(drive));
}
static void wait_device_selection(uint16_t drive)
{
for (int i = 0; i < 4; ++i)
inb(drive);
}
static uint8_t is_atapi_driver(uint16_t bus, uint8_t slave)
{
static uint8_t atapi_sig[] = { ATAPI_SIG_SC, ATAPI_SIG_LBA_LO,
ATAPI_SIG_LBA_MI, ATAPI_SIG_LBA_HI };
uint8_t sig[4];
sig[0] = inb(ATA_REG_SECTOR_COUNT(bus));
sig[1] = inb(ATA_REG_LBA_LO(bus));
sig[2] = inb(ATA_REG_LBA_MI(bus));
sig[3] = inb(ATA_REG_LBA_HI(bus));
if (!memcmp(sig, atapi_sig, 4))
{
struct atapi_drive d = { bus, slave };
if (bus == PRIMARY_REG)
{
if (slave)
drives[1] = d;
else
drives[0] = d;
}
else
{
if (slave)
drives[3] = d;
else
drives[2] = d;
}
return 1;
}
return 0;
}
void discover_atapi_drive(void)
{
// primary_reg
outb(PRIMARY_DCR, SRST);
outb(PRIMARY_DCR, INTERRUPT_DISABLE);
select_drive(PRIMARY_REG, ATA_PORT_MASTER);
wait_device_selection(PRIMARY_REG);
is_atapi_driver(PRIMARY_REG, ATA_PORT_MASTER);
// secondary_reg
outb(SECONDARY_DCR, SRST);
outb(SECONDARY_DCR, INTERRUPT_DISABLE);
}