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#include <asm/io.h>
#include <kernel/con.h>
#include <kernel/fs.h>
#include <kernel/kernel.h>
#include <stdint.h>
#include <sys/types.h>
#define SECTS(n) ((n) * (BLOCK_SIZE / 512))
#define BLOCKS(n) ((n) / (BLOCK_SIZE / 512))
#define ST_ERR 1
#define ST_DRQ 8
#define ST_SRV 16
#define ST_DF 32
#define ST_RDY 64
#define ST_BSY 128
/* status buffer */
static char sbuf[512];
static uint32_t nblocks;
static int read_sect(void *buf, uint32_t lba) {
int n;
uint8_t s;
uint16_t *p = buf;
if(lba > nblocks - 1)
return -1;
/* select the master disk on the primary bus */
outb(0x1F6, 0xE0 | ((lba >> 24) & 0xF));
/* set the number of sectors to be read */
outb(0x1F2, 1);
/* set the LBA address for the read operation */
outb(0x1F3, lba);
outb(0x1F4, lba >> 8);
outb(0x1F5, lba >> 16);
/* send the READ command */
outb(0x1F7, 0x20);
/* wait for the drive */
for(;;) {
/* poll the drive's status */
s = inb(0x1F7);
if(s & ST_DF) {
printk("[hd] Drive failure!\n");
panic();
}
if(s & ST_ERR)
return -1;
if(!(s & ST_BSY) && s & ST_DRQ)
break;
}
/* buffer is full, copy it's data */
n = 256;
while(n--)
*(p++) = inw(0x1F0);
return 0;
}
static int write_sect(void *buf, uint32_t lba) {
int n;
uint8_t s;
uint16_t *p = buf;
if(lba > nblocks - 1)
return -1;
/* select the master disk on the primary bus */
outb(0x1F6, 0xE0 | ((lba >> 24) & 0xF));
/* set the number of sectors to be written */
outb(0x1F2, 1);
/* set the LBA address for the write operation */
outb(0x1F3, lba);
outb(0x1F4, lba >> 8);
outb(0x1F5, lba >> 16);
/* send the WRITE command */
outb(0x1F7, 0x30);
/* wait for the drive */
for(;;) {
/* poll the drive's status */
s = inb(0x1F7);
if(s & ST_DF) {
printk("[hd] Drive failure!\n");
panic();
}
if(s & ST_ERR)
return -1;
if(!(s & ST_BSY) && s & ST_DRQ)
break;
}
/* refill the drive's buffer */
n = 256;
while(n--)
outw(0x1F0, *(p++));
return 0;
}
int hd_read_block(void *buf, uint16_t block) {
int ret;
size_t i;
uint32_t s = SECTS(block);
uint32_t e = SECTS(block + 1);
if(nblocks <= s || nblocks <= e)
return -1;
for(i = 0; i < (e - s); i++) {
ret = read_sect(buf, i + s);
if(ret < 0)
return -1;
buf = ((char*) buf + 512);
}
return 0;
}
int hd_write_block(void *buf, uint16_t block) {
int ret;
size_t i;
uint32_t s = SECTS(block);
uint32_t e = SECTS(block + 1);
if(nblocks <= s || nblocks <= e)
return -1;
for(i = 0; i < (e - s); i++) {
ret = write_sect(buf, i + s);
if(ret < 0)
return -1;
buf = ((char*) buf + 512);
}
return 0;
}
int hd_init(void) {
int i;
uint8_t s;
uint16_t *buf = (uint16_t*) sbuf;
/* select the master drive */
outb(0x1F6, 0xA0);
/* send the IDENTIFY command */
outb(0x1F7, 0xEC);
for(;;) {
s = inb(0x1F7);
if(!s) {
printk("[hd] Master drive not detected on primary bus!\n");
return -1;
}
if(s & ST_ERR) {
if(!inb(0x1F4) && !inb(0x1F5))
continue;
printk("[hd] IDENTIFY command error!\n");
return -1;
}
if(s & ST_DRQ && !(s & ST_ERR))
break;
}
for(i = 0; i < 256; i++)
buf[i] = inw(0x1F0);
nblocks = *((uint32_t*) &buf[60]);
if(!nblocks) {
printk("[hd] Drive does not support LBA28 addressing!\n");
return -1;
}
printk("[hd] Primary bus master drive initialized! (status: 0x%02X, nsects: 0x%01X)\n", s, nblocks);
return 0;
}
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