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feat(atapi): add send_packet and read_block implementations

This commit is contained in:
Malo Lecomte 2021-07-28 23:46:18 +02:00
parent 03648e3251
commit 7a7d87b02a
1 changed files with 64 additions and 5 deletions
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69
k/atapi.c
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@ -6,11 +6,7 @@
static struct atapi_drive drives[4] = { 0 };
static void select_drive(uint16_t bus, uint8_t slave)
{
outb(ATA_REG_DRIVE(bus), slave);
}
/* wait functions */
static void busy_wait(uint16_t drive)
{
int res = 0;
@ -24,6 +20,19 @@ static void wait_device_selection(uint16_t drive)
inb(drive);
}
static void wait_packet_request(uint16_t drive)
{
int res = 0;
while (res & BSY && !(res & DRQ))
res = inb(ATA_REG_STATUS(drive));
}
/* drive discover functions */
static void select_drive(uint16_t bus, uint8_t slave)
{
outb(ATA_REG_DRIVE(bus), slave);
}
static uint8_t is_atapi_drive(uint16_t bus, uint8_t slave)
{
static uint8_t atapi_sig[] = { ATAPI_SIG_SC, ATAPI_SIG_LBA_LO,
@ -89,3 +98,53 @@ void discover_atapi_drive(void)
wait_device_selection(SECONDARY_REG);
is_atapi_drive(SECONDARY_REG, ATA_PORT_SLAVE);
}
/* IO functions */
int send_packet(struct SCSI_packet *pkt, uint16_t drive, uint16_t size)
{
// cpy SCSI_packet into uint16_t array
uint16_t packet[PACKET_SZ / 2];
memcpy(packet, pkt, PACKET_SZ * sizeof(uint8_t));
// wait for a packet to be requested
busy_wait(drive);
outb(ATA_REG_FEATURES(drive), 0);
outb(ATA_REG_SECTOR_COUNT(drive), 0);
outb(ATA_REG_LBA_MI(drive), size);
outb(ATA_REG_LBA_HI(drive), size >> 8);
outb(ATA_REG_COMMAND(drive), PACKET);
wait_packet_request(drive);
// write SCSI packet
for (int i = 0; i < PACKET_SZ / 2; ++i)
outw(ATA_REG_DATA(drive), packet[i]);
uint8_t read = 0;
while (read != PACKET_DATA_TRANSMIT)
read = inb(ATA_REG_SECTOR_COUNT(drive));
return 0;
}
static char block[CD_BLOCK_SZ];
void read_block(size_t lba, uint16_t drive)
{
struct SCSI_packet pkt = { 0 };
pkt.op_code = READ_12;
pkt.lba_lo = lba & 0xff;
pkt.lba_milo = (lba >> 0x8) & 0xff;
pkt.lba_mihi = (lba >> 0x10) & 0xff;
pkt.lba_hi = (lba >> 0x18) & 0xff;
pkt.transfer_length_lo = 1;
send_packet(&pkt, drive, PACKET_SZ);
// we can now read
uint16_t *buf = block;
for (int i = 0; i < CD_BLOCK_SZ / 2; ++i)
buf[i] = inw(ATA_REG_DATA(drive));
uint8_t read = 0;
while (read != PACKET_COMMAND_COMPLETE)
read = inb(ATA_REG_SECTOR_COUNT(drive));
}