Files
blankos/src/drivers/ata.c
2024-08-24 17:23:26 +02:00

63 lines
1.6 KiB
C

// ATA PIO driver implementation
// Author: xamidev
// Licensed under the Unlicense. See the repo below.
// https://github.com/xamidev/blankos
#include <stdint.h>
#include "../kernel/io.h"
#include "../libc/stdio.h"
#include "ata.h"
static inline uint16_t inw(uint16_t port) {
uint16_t result;
asm volatile("inw %1, %0" : "=a"(result) : "dN"(port));
return result;
}
static inline void outw(uint16_t port, uint16_t data) {
asm volatile("outw %1, %0" : : "dN"(port), "a"(data));
}
void ata_wait_bsy() {
while (inb(ATA_PRIMARY_IO + ATA_REG_STATUS) & ATA_SR_BSY);
}
void ata_wait_drq() {
while (!(inb(ATA_PRIMARY_IO + ATA_REG_STATUS) & ATA_SR_DRQ));
}
void ata_select_drive(uint8_t drive) {
outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, 0xE0 | (drive << 4));
}
void ata_read_sector(uint32_t lba, uint8_t* buffer) {
ata_wait_bsy();
ata_select_drive(0);
outb(ATA_PRIMARY_IO + ATA_REG_SECCOUNT0, 1);
outb(ATA_PRIMARY_IO + ATA_REG_LBA0, (uint8_t)lba);
outb(ATA_PRIMARY_IO + ATA_REG_LBA1, (uint8_t)(lba >> 8));
outb(ATA_PRIMARY_IO + ATA_REG_LBA2, (uint8_t)(lba >> 16));
outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, 0xE0 | ((lba >> 24) & 0x0F));
outb(ATA_PRIMARY_IO + ATA_REG_COMMAND, ATA_CMD_READ_PIO);
ata_wait_bsy();
ata_wait_drq();
for (int i = 0; i < 256; i++) {
((uint16_t*)buffer)[i] = inw(ATA_PRIMARY_IO + ATA_REG_DATA);
}
}
// Works only w/o paging
void test_read_sector() {
uint8_t buffer[512];
ata_read_sector(0, buffer);
for (int i = 0; i < 512; i++) {
if (i%25==0) puts("\n");
printf("%02x ", buffer[i]);
}
}