ide.c

Hermit-at-1.1.3,一款bootloader

/*
 * Copyright (c) 2006 Atmark Techno, Inc.  All Rights Reserved.
 */

#include <target/io.h>

#define MULTIPLE                 3

#define TIMEOUT                  50000

#define IDE_DATA                 0x62000000
#define IDE_ERROR                0x62000002
#define IDE_FEAUTURES            0x62000002
#define IDE_SECTOR_COUNT         0x62000004
#define IDE_SECTOR_NUMBER        0x62000006
#define IDE_SECTOR_CYLINDER_LOW  0x62000008
#define IDE_SECTOR_CYLINDER_HIGH 0x6200000a
#define IDE_DEVICE_HEAD          0x6200000c
#define IDE_STATUS               0x6200000e
#define IDE_COMMAND              0x6200000e
#define IDE_ALTERNATE_STATUS     0x6200002c
#define IDE_DEVICE_CONTROL       0x6200002c

#define IDE_STATUS_BUSY          0x80
#define IDE_STATUS_DRDY          0x40
#define IDE_STATUS_DRQ           0x08
#define IDE_STATUS_ERR           0x01

#define IDE_COMMAND_READ_SECTORS 0x20
#define IDE_COMMAND_IDLE         0xe3
#define IDE_COMMAND_IDENTIFY     0xec

#define IDE_DEVICE_CONTROL_SRST  0x04
#define IDE_DEVICE_CONTROL_NIEN  0x02

#define IDE_LBA                  0x40

#define ide_inb(port)    (*(volatile unsigned char *)(port))
#define ide_inw(port)    (*(volatile unsigned short *)(port))
#define ide_outb(b,port) (*(volatile unsigned char *)(port)=(b))
#define ide_outw(w,port) (*(volatile unsigned short *)(port)=(w))

#define delay(count) {int d;for(d=0;d<(count*MULTIPLE);d++);}

static int wait_nbusy_ndrq (void)
{
  int i;
  
  for (i = 0; i < TIMEOUT && (ide_inb (IDE_ALTERNATE_STATUS) &
			      (IDE_STATUS_BUSY | IDE_STATUS_DRQ)); i++) {
    delay (100);
  }
  if (i >= TIMEOUT) {
    return -1;
  }
  
  return 0;
}

static int wait_nbusy (void)
{
  int i;
  
  for (i = 0; i < TIMEOUT && (ide_inb (IDE_ALTERNATE_STATUS) &
			      IDE_STATUS_BUSY); i++) {
    delay (100);
  }
  if (i >= TIMEOUT) {
    return -1;
  }
  
  return 0;
}

static int wait_ready (void)
{
  int i;
  
  for (i = 0; i < TIMEOUT && !(ide_inb (IDE_ALTERNATE_STATUS) &
			      IDE_STATUS_DRDY); i++) {
    delay (100);
  }
  if (i >= TIMEOUT) {
    return -1;
  }
  
  return 0;
}

static int ide_reset (void)
{
  int ret;
  unsigned char error;
  
  ide_outb (IDE_DEVICE_CONTROL_SRST | IDE_DEVICE_CONTROL_NIEN,
	    IDE_DEVICE_CONTROL);
  delay (40000);
  
  ide_outb (IDE_DEVICE_CONTROL_NIEN, IDE_DEVICE_CONTROL);
  delay (40000);
  
  ret = wait_nbusy ();
  if (ret) {
    return ret;
  }

  error = ide_inb (IDE_ERROR);
  if (error != 0 && error != 1) {
    return -1;
  }
  
  return 0;
}

static int ide_device_selection (int dev)
{
  int ret;
  
  ret = wait_nbusy_ndrq ();
  if (ret) {
    return ret;
  }
  
  ide_outb (IDE_DEVICE_CONTROL_NIEN, IDE_DEVICE_CONTROL);
  ide_outb (dev << 4, IDE_DEVICE_HEAD);
  delay (100);
  
  return wait_nbusy_ndrq ();
}

static int ide_register_check (void)
{
  ide_outb (0x55, IDE_SECTOR_CYLINDER_LOW);
  ide_outb (0xaa, IDE_SECTOR_CYLINDER_HIGH);
  if (ide_inb (IDE_SECTOR_CYLINDER_LOW) != 0x55) {
    return -1;
  }
  if (ide_inb (IDE_SECTOR_CYLINDER_HIGH) != 0xaa) {
    return -1;
  }
  
  return 0;
}

static int ide_get_data (unsigned char *buf, int count)
{
  int            ret, i;
  unsigned short data;
  
  while (count--) {
    ret = wait_nbusy ();
    if (ret) {
      return ret;
    }
    
    if (ide_inb (IDE_ALTERNATE_STATUS) & IDE_STATUS_ERR) {
      return -1;
    }

    for (i = 0; i < 256; i++) {
      data = ide_inw (IDE_DATA);
      *buf++ = data & 0xff;
      *buf++ = data >> 8;
    }
  }
  
  return 0;
}

static void ide_fix_string (unsigned char *dest, unsigned char *src, int num)
{
  int i;
  
  for (i = 0; i < num; i+= 2) {
    *dest++ = *(src + 1);
    *dest++ = *src;
    src += 2;
  }
  while (*--dest == (' '))
    ;
  ++dest;
  *dest++ = ' ';
  *dest++ = '\0';
}

static int ide_identify_device (int dev)
{
  int            ret;
  unsigned short buf[256];
  unsigned char  name[42];
  
  ret = ide_device_selection (dev);
  if (ret) {
    return ret;
  }
  
  ret = wait_ready ();
  if (ret) {
    return ret;
  }
  
  ide_outb (IDE_COMMAND_IDENTIFY, IDE_COMMAND);
  delay (100);
  
  ret = ide_get_data ((unsigned char *)buf, 1);
  if (ret) {
    return ret;
  }
  
  if (*buf & 0x04) {
    return -1;
  }
  
  hprintf ("Disk drive detected: ");
  ide_fix_string (name, (unsigned char *)&buf[27], 40);
  hprintf ("%s", name);
  ide_fix_string (name, (unsigned char *)&buf[23], 8);
  hprintf ("%s", name);
  ide_fix_string (name, (unsigned char *)&buf[10], 20);
  hprintf ("%s", name);
  hprintf ("\n");
  
  return 0;
}

static int ide_idle (int dev)
{
  int ret;
  
  ret = ide_device_selection (0);
  if (ret) {
    return ret;
  }
  
  ret = wait_ready ();
  if (ret) {
    return ret;
  }
  
  ide_outb (0x00, IDE_SECTOR_COUNT);
  ide_outb (IDE_COMMAND_IDLE, IDE_COMMAND);
  delay (100);
  
  return wait_nbusy_ndrq ();
}

int ide_detect_devices ()
{
  int ret;

  ret = ide_reset ();
  if (ret) {
    return ret;
  }
  
  ret = ide_device_selection (0);
  if (ret) {
    return ret;
  }
  
  ret = ide_register_check ();
  if (ret) {
    return ret;
  }
  
  return ide_identify_device (0);
}

int ide_startup_devices (void)
{
  return ide_idle (0);
}

int ide_read_sectors (int dev, unsigned long lba,
		      unsigned char *buf, int count)
{
  int ret;
  
  ret = ide_device_selection (dev);
  if (ret) {
    return ret;
  }
  
  ret = wait_ready ();
  if (ret) {
    return ret;
  }
  
  ide_outb (count, IDE_SECTOR_COUNT);
  ide_outb (lba & 0xff, IDE_SECTOR_NUMBER);
  ide_outb ((lba & 0xff00) >> 8, IDE_SECTOR_CYLINDER_LOW);
  ide_outb ((lba & 0xff0000) >> 16, IDE_SECTOR_CYLINDER_HIGH);
  ide_outb (IDE_LBA | (dev << 4) | ((lba & 0xf000000) >> 24), IDE_DEVICE_HEAD);
  
  ide_outb (IDE_COMMAND_READ_SECTORS, IDE_COMMAND);
  delay (100);
  
  return ide_get_data (buf, count);
}