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#include <stdbool.h>
#include <stdint.h>
#include "drive.h"
#include "panic.h"
#include "util.h"
#include "ata.h"
#include "pci.h"
#define MAX_IDE_DRIVES 8
struct ide_drive_info {
uint16_t base_port;
uint16_t alt_port;
bool slave;
};
static struct ide_drive_info ide_drives[MAX_IDE_DRIVES];
static drive_id_t n_ide_drives;
typedef uint16_t spinner_t;
//returns the status after waiting
static uint8_t wait_for_ready(uint16_t base_port) {
for (spinner_t n = -1; n; --n) {
uint8_t s = inb(base_port | ATA_REG_STATUS);
if (s & ATA_STATUS_ERROR)
PANIC("Error status in IDE driver.");
if (s & ATA_STATUS_DRIVE_READY)
return s;
}
PANIC("Spun out in IDE driver.");
}
//returns the status after waiting
static uint8_t wait_for_error_or_ready(uint16_t base_port) {
for (spinner_t n = -1; n; --n) {
uint8_t s = inb(base_port | ATA_REG_STATUS);
if (s & (ATA_STATUS_DRIVE_READY | ATA_STATUS_ERROR))
return s;
}
PANIC("Spun out in IDE driver.");
}
//returns the status after waiting
static uint8_t wait_for_data_ready_not_busy(uint16_t base_port) {
for (spinner_t n = -1; n; --n) {
uint8_t s = inb(base_port | ATA_REG_STATUS);
if (!(s & ATA_STATUS_BUSY) && (s & ATA_STATUS_DATA_READY))
return s;
if (s & ATA_STATUS_ERROR)
PANIC("Error status in IDE driver.");
}
PANIC("Spun out in IDE driver.");
}
static uint32_t ide_ata_rs(const struct drive *d, uint32_t start, uint32_t count, void *buffer) {
if (start >= d->n_sectors)
return 0;
if (start + count > d->n_sectors)
count = d->n_sectors - start;
if (!count)
return 0;
if (start & 0xf0000000)
PANIC("IDE ATA driver does not support reads starting past 256MiB currently.");
if (count & 0xffffff00)
PANIC("IDE ATA driver does not support reads over 128kiB in length currently.");
uint32_t lba = start & 0x00ffffff;
struct ide_drive_info *info = ide_drives + d->drive_id;
outb(info->base_port | ATA_REG_SELECT, (info->slave ? 0xf0 : 0xe0) | (start >> 24));
//spin?
outb(info->base_port | ATA_REG_COUNT, count);
outb(info->base_port | ATA_REG_LBA0, lba);
outb(info->base_port | ATA_REG_LBA1, lba >> 8);
outb(info->base_port | ATA_REG_LBA2, lba >> 16);
outb(info->base_port | ATA_REG_CMD, ATA_CMD_READ);
uint16_t *buf16 = (uint16_t *)buffer;
for (uint16_t i = 0; i < count; ++i) {
wait_for_data_ready_not_busy(info->base_port);
for (uint16_t j = 0; j < 256; ++j)
*buf16++ = inw(info->base_port | ATA_REG_DATA);
}
return count;
}
static uint32_t ide_ata_ws(const struct drive *d, uint32_t start, uint32_t count, const void *buffer) {
PANIC("IDE ATA writing not implemented yet.");
}
static uint32_t ide_atapi_rs(const struct drive *d, uint32_t start, uint32_t count, void *buffer) {
if (start >= d->n_sectors)
return 0;
if (start + count > d->n_sectors)
count = d->n_sectors - start;
if (!count)
return 0;
PANIC("IDE ATAPI reading not implemented yet.");
}
static uint32_t ide_atapi_ws(const struct drive *d, uint32_t start, uint32_t count, const void *buffer) {
PANIC("IDE ATAPI writing not implemented yet.");
}
static void nop(const struct drive *d) { }
struct id_space {
uint8_t skip1[120];
uint32_t max_lba;//120
uint8_t skip2[512 - (120 + 4)];
} __attribute__ ((__packed__ ));
static void test_drive(uint16_t base_port, uint16_t alt_port, bool slave) {
if (n_ide_drives == MAX_IDE_DRIVES)
PANIC("Maximum number of IDE drives reached.");
struct ide_drive_info *next = ide_drives + n_ide_drives;
struct drive next_d;
next_d.drive_id = n_ide_drives;
next->base_port = base_port;
next->alt_port = alt_port;
next->slave = slave;
outb(base_port | ATA_REG_SELECT, slave ? 0xb0 : 0xa0);
outb(base_port | ATA_REG_COUNT, 0);
outb(base_port | ATA_REG_LBA0, 0);
outb(base_port | ATA_REG_LBA1, 0);
outb(base_port | ATA_REG_LBA2, 0);
outb(base_port | ATA_REG_CMD, ATA_CMD_ID);
uint8_t status = inb(base_port | ATA_REG_STATUS);
if (!status || (status == 0x7f))
return;
next_d.ready = &nop;
next_d.done = &nop;
struct id_space ids;
if (!(wait_for_error_or_ready(base_port) & ATA_STATUS_ERROR)) {
wait_for_ready(base_port);
for (uint16_t *ids_16 = (uint16_t *)&ids; ids_16 < (uint16_t *)&ids + 256; ++ids_16)
*ids_16 = inw(base_port | ATA_REG_DATA);
next_d.drive_type = "IDE PATA";
next_d.read_sectors = &ide_ata_rs;
next_d.write_sectors = &ide_ata_ws;
}
else {
uint16_t code = inb(base_port | 0x4) + (inb(base_port | 0x5) << 8);
if (!code) {
PANIC("PATA identification aborted.");
}
if (code == 0xeb14) {
next_d.drive_type = "IDE PATAPI";
next_d.read_sectors = &ide_atapi_rs;
next_d.write_sectors = &ide_atapi_ws;
//TODO: issue proper identify command
return;
}
else if (code == 0xc33c) {
next_d.drive_type = "IDE SATA";
//TODO: set up drive hooks, issue proper identify command
return;
}
}
//in the future, maybe add support for 48-bit LBA, and/or CHS addressing
if (!ids.max_lba)
PANIC("Encountered ATA drive that doesn't support 28-bit LBA.");
next_d.n_sectors = ids.max_lba;
commit_drive(next_d);
++n_ide_drives;
}
void init_ide() {
n_ide_drives = 0;
uint16_t check_from = 0;
struct pci_device *device;
//double parentheses to let gcc know this assignment isn't a mistake
while ((device = find_pci_device_from_class_and_subclass(PCI_MASS_STORAGE, PCI_IDE, check_from, &check_from))) {
++check_from;
test_drive(0x01f0, 0x03f6, false);
test_drive(0x01f0, 0x03f6, true);
test_drive(0x0170, 0x0376, false);
test_drive(0x0170, 0x0376, true);
}
}
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