asmstub.c

i386的bootloader源码grub

  return c;
}

/* like 'getkey', but doesn't wait, returns -1 if nothing available */
int
console_checkkey (void)
{
#ifdef HAVE_LIBCURSES
  if (use_curses)
    {
      int c;

      /* Check for SAVE_CHAR. This should not be true, because this
	 means checkkey is called twice continuously.  */
      if (save_char != ERR)
	return save_char;

      c = getch ();
      /* If C is not ERR, then put it back in the input queue.  */
      if (c != ERR)
	save_char = c;
      return console_translate_key (c);
    }
#endif

  /* Just pretend they hit the space bar, then read the real key when
     they call getkey. */
  return ' ';
}

/* returns packed BIOS/ASCII code */
int
console_getkey (void)
{
  int c;

#ifdef HAVE_LIBCURSES
  if (use_curses)
    {
      /* If checkkey has already got a character, then return it.  */
      if (save_char != ERR)
	{
	  c = save_char;
	  save_char = ERR;
	  return console_translate_key (c);
	}

      wtimeout (stdscr, -1);
      c = getch ();
      wtimeout (stdscr, 100);
    }
  else
#endif
    c = getchar ();

  /* Quit if we get EOF. */
  if (c == -1)
    stop ();
  
  return console_translate_key (c);
}

/* returns packed values, LSB+1 is x, LSB is y */
int
console_getxy (void)
{
  int y, x;
#ifdef HAVE_LIBCURSES
  if (use_curses)
    getyx (stdscr, y, x);
  else
#endif
  y = x = 0;
  return (x << 8) | (y & 0xff);
}

void
console_gotoxy (int x, int y)
{
#ifdef HAVE_LIBCURSES
  if (use_curses)
    move (y, x);
#endif
}

/* low-level character I/O */
void
console_cls (void)
{
#ifdef HAVE_LIBCURSES
  if (use_curses)
    clear ();
#endif
}

void
console_setcolorstate (color_state state)
{
  console_current_color = 
    (state == COLOR_STATE_HIGHLIGHT) ? A_REVERSE : A_NORMAL;
}

void
console_setcolor (int normal_color, int highlight_color)
{
  /* Nothing to do.  */
}

int
console_setcursor (int on)
{
  return 1;
}

/* Low-level disk I/O.  Our stubbed version just returns a file
   descriptor, not the actual geometry. */
int
get_diskinfo (int drive, struct geometry *geometry)
{
  /* FIXME: this function is truly horrid.  We try opening the device,
     then severely abuse the GEOMETRY->flags field to pass a file
     descriptor to biosdisk.  Thank God nobody's looking at this comment,
     or my reputation would be ruined. --Gord */

  /* See if we have a cached device. */
  if (disks[drive].flags == -1)
    {
      /* The unpartitioned device name: /dev/XdX */
      char *devname = device_map[drive];
      char buf[512];

      if (! devname)
	return -1;

      if (verbose)
	grub_printf ("Attempt to open drive 0x%x (%s)\n",
		     drive, devname);

      /* Open read/write, or read-only if that failed. */
      if (! read_only)
	disks[drive].flags = open (devname, O_RDWR);

      if (disks[drive].flags == -1)
	{
	  if (read_only || errno == EACCES || errno == EROFS || errno == EPERM)
	    {
	      disks[drive].flags = open (devname, O_RDONLY);
	      if (disks[drive].flags == -1)
		{
		  assign_device_name (drive, 0);
		  return -1;
		}
	    }
	  else
	    {
	      assign_device_name (drive, 0);
	      return -1;
	    }
	}

      /* Attempt to read the first sector.  */
      if (read (disks[drive].flags, buf, 512) != 512)
	{
	  close (disks[drive].flags);
	  disks[drive].flags = -1;
	  assign_device_name (drive, 0);
	  return -1;
	}

      if (disks[drive].flags != -1)
	get_drive_geometry (&disks[drive], device_map, drive);
    }

  if (disks[drive].flags == -1)
    return -1;

#ifdef __linux__
  /* In Linux, invalidate the buffer cache, so that left overs
     from other program in the cache are flushed and seen by us */
  ioctl (disks[drive].flags, BLKFLSBUF, 0);
#endif

  *geometry = disks[drive];
  return 0;
}

/* Read LEN bytes from FD in BUF. Return less than or equal to zero if an
   error occurs, otherwise return LEN.  */
static int
nread (int fd, char *buf, size_t len)
{
  int size = len;

  while (len)
    {
      int ret = read (fd, buf, len);

      if (ret <= 0)
	{
	  if (errno == EINTR)
	    continue;
	  else
	    return ret;
	}

      len -= ret;
      buf += ret;
    }

  return size;
}

/* Write LEN bytes from BUF to FD. Return less than or equal to zero if an
   error occurs, otherwise return LEN.  */
static int
nwrite (int fd, char *buf, size_t len)
{
  int size = len;

  while (len)
    {
      int ret = write (fd, buf, len);

      if (ret <= 0)
	{
	  if (errno == EINTR)
	    continue;
	  else
	    return ret;
	}

      len -= ret;
      buf += ret;
    }

  return size;
}

/* Dump BUF in the format of hexadecimal numbers.  */
static void
hex_dump (void *buf, size_t size)
{
  /* FIXME: How to determine which length is readable?  */
#define MAX_COLUMN	70

  /* use unsigned char for numerical computations */
  unsigned char *ptr = buf;
  /* count the width of the line */
  int column = 0;
  /* how many bytes written */
  int count = 0;

  while (size > 0)
    {
      /* high 4 bits */
      int hi = *ptr >> 4;
      /* low 4 bits */
      int low = *ptr & 0xf;

      /* grub_printf does not handle prefix number, such as %2x, so
	 format the number by hand...  */
      grub_printf ("%x%x", hi, low);
      column += 2;
      count++;
      ptr++;
      size--;

      /* Insert space or newline with the interval 4 bytes.  */
      if (size != 0 && (count % 4) == 0)
	{
	  if (column < MAX_COLUMN)
	    {
	      grub_printf (" ");
	      column++;
	    }
	  else
	    {
	      grub_printf ("\n");
	      column = 0;
	    }
	}
    }

  /* Add a newline at the end for readability.  */
  grub_printf ("\n");
}

int
biosdisk (int subfunc, int drive, struct geometry *geometry,
	  int sector, int nsec, int segment)
{
  char *buf;
  int fd = geometry->flags;

  /* Get the file pointer from the geometry, and make sure it matches. */
  if (fd == -1 || fd != disks[drive].flags)
    return BIOSDISK_ERROR_GEOMETRY;

  /* Seek to the specified location. */
#if defined(__linux__) && (!defined(__GLIBC__) || \
	((__GLIBC__ < 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ < 1))))
  /* Maybe libc doesn't have large file support.  */
  {
    loff_t offset, result;
    static int _llseek (uint filedes, ulong hi, ulong lo,
			loff_t *res, uint wh);
    _syscall5 (int, _llseek, uint, filedes, ulong, hi, ulong, lo,
	       loff_t *, res, uint, wh);

    offset = (loff_t) sector * (loff_t) SECTOR_SIZE;
    if (_llseek (fd, offset >> 32, offset & 0xffffffff, &result, SEEK_SET))
      return -1;
  }
#else
  {
    off_t offset = (off_t) sector * (off_t) SECTOR_SIZE;

    if (lseek (fd, offset, SEEK_SET) != offset)
      return -1;
  }
#endif

  buf = (char *) (segment << 4);

  switch (subfunc)
    {
    case BIOSDISK_READ:
#ifdef __linux__
      if (sector == 0 && nsec > 1)
	{
	  /* Work around a bug in linux's ez remapping.  Linux remaps all
	     sectors that are read together with the MBR in one read.  It
	     should only remap the MBR, so we split the read in two 
	     parts. -jochen  */
	  if (nread (fd, buf, SECTOR_SIZE) != SECTOR_SIZE)
	    return -1;
	  buf += SECTOR_SIZE;
	  nsec--;
	}
#endif
      if (nread (fd, buf, nsec * SECTOR_SIZE) != nsec * SECTOR_SIZE)
	return -1;
      break;

    case BIOSDISK_WRITE:
      if (verbose)
	{
	  grub_printf ("Write %d sectors starting from %d sector"
		       " to drive 0x%x (%s)\n",
		       nsec, sector, drive, device_map[drive]);
	  hex_dump (buf, nsec * SECTOR_SIZE);
	}
      if (! read_only)
	if (nwrite (fd, buf, nsec * SECTOR_SIZE) != nsec * SECTOR_SIZE)
	  return -1;
      break;

    default:
      grub_printf ("unknown subfunc %d\n", subfunc);
      break;
    }

  return 0;
}


void
stop_floppy (void)
{
  /* NOTUSED */
}

/* Fetch a key from a serial device.  */
int
serial_hw_fetch (void)
{
  fd_set fds;
  struct timeval to;
  char c;

  /* Wait only for the serial device.  */
  FD_ZERO (&fds);
  FD_SET (serial_fd, &fds);

  to.tv_sec = 0;
  to.tv_usec = 0;
  
  if (select (serial_fd + 1, &fds, 0, 0, &to) > 0)
    {
      if (nread (serial_fd, &c, 1) != 1)
	stop ();

      return c;
    }
  
  return -1;
}

/* Put a character to a serial device.  */
void
serial_hw_put (int c)
{
  char ch = (char) c;
  
  if (nwrite (serial_fd, &ch, 1) != 1)
    stop ();
}

void
serial_hw_delay (void)
{
#ifdef SIMULATE_SLOWNESS_OF_SERIAL
  struct timeval otv, tv;

  gettimeofday (&otv, 0);

  while (1)
    {
      long delta;
      
      gettimeofday (&tv, 0);
      delta = tv.tv_usec - otv.tv_usec;
      if (delta < 0)
	delta += 1000000;
      
      if (delta >= 1000000 / (serial_speed >> 3))
	break;
    }
#endif /* SIMULATE_SLOWNESS_OF_SERIAL */
}

static speed_t
get_termios_speed (int speed)
{
  switch (speed)
    {
    case 2400: return B2400;
    case 4800: return B4800;
    case 9600: return B9600;
    case 19200: return B19200;
    case 38400: return B38400;
#ifdef B57600
    case 57600: return B57600;
#endif
#ifdef B115200      
    case 115200: return B115200;
#endif
    }

  return B0;
}

/* Get the port number of the unit UNIT. In the grub shell, this doesn't
   make sense.  */
unsigned short
serial_hw_get_port (int unit)
{
  return 0;
}

/* Initialize a serial device. In the grub shell, PORT is unused.  */
int
serial_hw_init (unsigned short port, unsigned int speed,
		int word_len, int parity, int stop_bit_len)
{
  struct termios termios;
  speed_t termios_speed;
  int i;
  
  /* Check if the file name is specified.  */
  if (! serial_device)
    return 0;

  /* If a serial device is already opened, close it first.  */
  if (serial_fd >= 0)
    close (serial_fd);
  
  /* Open the device file.  */
  serial_fd = open (serial_device,
		    O_RDWR | O_NOCTTY
#if defined(O_SYNC)
		    /* O_SYNC is used in Linux (and some others?).  */
		    | O_SYNC
#elif defined(O_FSYNC)
		    /* O_FSYNC is used in FreeBSD.  */
		    | O_FSYNC
#endif
		    );
  if (serial_fd < 0)
    return 0;

  /* Get the termios parameters.  */
  if (tcgetattr (serial_fd, &termios))
    goto fail;

  /* Raw mode.  */
  cfmakeraw (&termios);

  /* Set the speed.  */
  termios_speed = get_termios_speed (speed);
  if (termios_speed == B0)
    goto fail;
  
  cfsetispeed (&termios, termios_speed);
  cfsetospeed (&termios, termios_speed);

  /* Set the word length.  */
  termios.c_cflag &= ~CSIZE;
  switch (word_len)
    {
    case UART_5BITS_WORD:
      termios.c_cflag |= CS5;
      break;
    case UART_6BITS_WORD:
      termios.c_cflag |= CS6;
      break;
    case UART_7BITS_WORD:
      termios.c_cflag |= CS7;
      break;
    case UART_8BITS_WORD:
      termios.c_cflag |= CS8;
      break;
    default:
      goto fail;
    }

  /* Set the parity.  */
  switch (parity)
    {
    case UART_NO_PARITY:
      termios.c_cflag &= ~PARENB;
      break;
    case UART_ODD_PARITY:
      termios.c_cflag |= PARENB;
      termios.c_cflag |= PARODD;
      break;
    case UART_EVEN_PARITY:
      termios.c_cflag |= PARENB;
      termios.c_cflag &= ~PARODD;
      break;
    default:
      goto fail;
    }

  /* Set the length of stop bit.  */
  switch (stop_bit_len)
    {
    case UART_1_STOP_BIT:
      termios.c_cflag &= ~CSTOPB;
      break;
    case UART_2_STOP_BITS:
      termios.c_cflag |= CSTOPB;
      break;
    default:
      goto fail;
    }

  /* Set the parameters.  */
  if (tcsetattr (serial_fd, TCSANOW, &termios))
    goto fail;

#ifdef SIMULATE_SLOWNESS_OF_SERIAL
  serial_speed = speed;
#endif /* SIMUATE_SLOWNESS_OF_SERIAL */

  /* Get rid of the flag TERM_NEED_INIT from the serial terminal.  */
  for (i = 0; term_table[i].name; i++)
    {
      if (strcmp (term_table[i].name, "serial") == 0)
	{
	  term_table[i].flags &= ~(TERM_NEED_INIT);
	  break;
	}
    }
  
  return 1;

 fail:
  close (serial_fd);
  serial_fd = -1;
  return 0;
}

/* Set the file name of a serial device (or a pty device). This is a
   function specific to the grub shell.  */
void
serial_set_device (const char *device)
{
  if (serial_device)
    free (serial_device);
  
  serial_device = strdup (device);
}

/* There is no difference between console and hercules in the grub shell.  */
void
hercules_putchar (int c)
{
  console_putchar (c);
}

int
hercules_getxy (void)
{
  return console_getxy ();
}

void
hercules_gotoxy (int x, int y)
{
  console_gotoxy (x, y);
}

void
hercules_cls (void)
{
  console_cls ();
}

void
hercules_setcolorstate (color_state state)
{
  console_setcolorstate (state);
}

void
hercules_setcolor (int normal_color, int highlight_color)
{
  console_setcolor (normal_color, highlight_color);
}

int
hercules_setcursor (int on)
{
  return 1;
}