char_io.c

i386的bootloader源码grub

	      break;
	    case 2:		/* C-b backward one character */
	      if (lpos > 0)
		cl_backward (1);
	      break;
	    case 21:		/* C-u kill to beginning of line */
	      if (lpos == 0)
		break;
	      /* Copy the string being deleted to KILL_BUF.  */
	      grub_memmove (kill_buf, buf, lpos);
	      kill_buf[lpos] = 0;
	      {
		/* XXX: Not very clever.  */
		
		int count = lpos;
		
		cl_backward (lpos);
		cl_delete (count);
	      }
	      break;
	    case 11:		/* C-k kill to end of line */
	      if (lpos == llen)
		break;
	      /* Copy the string being deleted to KILL_BUF.  */
	      grub_memmove (kill_buf, buf + lpos, llen - lpos + 1);
	      cl_delete (llen - lpos);
	      break;
	    case 25:		/* C-y yank the kill buffer */
	      cl_insert (kill_buf);
	      break;
	    case 16:		/* C-p fetch the previous command */
	      {
		char *p;

		if (history < 0)
		  /* Save the working buffer.  */
		  grub_strcpy (cmdline, buf);
		else if (grub_strcmp (get_history (history), buf) != 0)
		  /* If BUF is modified, add it into the history list.  */
		  add_history (buf, history);

		history++;
		p = get_history (history);
		if (! p)
		  {
		    history--;
		    break;
		  }

		grub_strcpy (buf, p);
		llen = grub_strlen (buf);
		lpos = llen;
		cl_refresh (1, 0);
	      }
	      break;
	    case 14:		/* C-n fetch the next command */
	      {
		char *p;

		if (history < 0)
		  {
		    break;
		  }
		else if (grub_strcmp (get_history (history), buf) != 0)
		  /* If BUF is modified, add it into the history list.  */
		  add_history (buf, history);

		history--;
		p = get_history (history);
		if (! p)
		  p = cmdline;

		grub_strcpy (buf, p);
		llen = grub_strlen (buf);
		lpos = llen;
		cl_refresh (1, 0);
	      }
	      break;
	    }
	}

      /* ESC, C-d and C-h are always handled. Actually C-d is not
	 functional if READLINE is zero, as the cursor cannot go
	 backward, but that's ok.  */
      switch (c)
	{
	case 27:	/* ESC immediately return 1 */
	  return 1;
	case 4:		/* C-d delete character under cursor */
	  if (lpos == llen)
	    break;
	  cl_delete (1);
	  break;
	case 8:		/* C-h backspace */
# ifdef GRUB_UTIL
	case 127:	/* also backspace */
# endif
	  if (lpos > 0)
	    {
	      cl_backward (1);
	      cl_delete (1);
	    }
	  break;
	default:		/* insert printable character into line */
	  if (c >= ' ' && c <= '~')
	    {
	      char str[2];

	      str[0] = c;
	      str[1] = 0;
	      cl_insert (str);
	    }
	}
    }

  grub_putchar ('\n');

  /* If ECHO_CHAR is NUL, remove the leading spaces.  */
  lpos = 0;
  if (! echo_char)
    while (buf[lpos] == ' ')
      lpos++;

  /* Copy the working buffer to CMDLINE.  */
  grub_memmove (cmdline, buf + lpos, llen - lpos + 1);

  /* If the readline-like feature is turned on and CMDLINE is not
     empty, add it into the history list.  */
  if (readline && lpos < llen)
    add_history (cmdline, 0);

  return 0;
}

/* Don't use this with a MAXLEN greater than 1600 or so!  The problem
   is that GET_CMDLINE depends on the everything fitting on the screen
   at once.  So, the whole screen is about 2000 characters, minus the
   PROMPT, and space for error and status lines, etc.  MAXLEN must be
   at least 1, and PROMPT and CMDLINE must be valid strings (not NULL
   or zero-length).

   If ECHO_CHAR is nonzero, echo it instead of the typed character. */
int
get_cmdline (char *prompt, char *cmdline, int maxlen,
	     int echo_char, int readline)
{
  int old_cursor;
  int ret;

  old_cursor = setcursor (1);
  
  /* Because it is hard to deal with different conditions simultaneously,
     less functional cases are handled here. Assume that TERM_NO_ECHO
     implies TERM_NO_EDIT.  */
  if (current_term->flags & (TERM_NO_ECHO | TERM_NO_EDIT))
    {
      char *p = cmdline;
      int c;
      
      /* Make sure that MAXLEN is not too large.  */
      if (maxlen > MAX_CMDLINE)
	maxlen = MAX_CMDLINE;

      /* Print only the prompt. The contents of CMDLINE is simply discarded,
	 even if it is not empty.  */
      grub_printf ("%s", prompt);

      /* Gather characters until a newline is gotten.  */
      while ((c = ASCII_CHAR (getkey ())) != '\n' && c != '\r')
	{
	  /* Return immediately if ESC is pressed.  */
	  if (c == 27)
	    {
	      setcursor (old_cursor);
	      return 1;
	    }

	  /* Printable characters are added into CMDLINE.  */
	  if (c >= ' ' && c <= '~')
	    {
	      if (! (current_term->flags & TERM_NO_ECHO))
		grub_putchar (c);

	      /* Preceding space characters must be ignored.  */
	      if (c != ' ' || p != cmdline)
		*p++ = c;
	    }
	}

      *p = 0;

      if (! (current_term->flags & TERM_NO_ECHO))
	grub_putchar ('\n');

      setcursor (old_cursor);
      return 0;
    }

  /* Complicated features are left to real_get_cmdline.  */
  ret = real_get_cmdline (prompt, cmdline, maxlen, echo_char, readline);
  setcursor (old_cursor);
  return ret;
}

int
safe_parse_maxint (char **str_ptr, int *myint_ptr)
{
  char *ptr = *str_ptr;
  int myint = 0;
  int mult = 10, found = 0;

  /*
   *  Is this a hex number?
   */
  if (*ptr == '0' && tolower (*(ptr + 1)) == 'x')
    {
      ptr += 2;
      mult = 16;
    }

  while (1)
    {
      /* A bit tricky. This below makes use of the equivalence:
	 (A >= B && A <= C) <=> ((A - B) <= (C - B))
	 when C > B and A is unsigned.  */
      unsigned int digit;

      digit = tolower (*ptr) - '0';
      if (digit > 9)
	{
	  digit -= 'a' - '0';
	  if (mult == 10 || digit > 5)
	    break;
	  digit += 10;
	}

      found = 1;
      if (myint > ((MAXINT - digit) / mult))
	{
	  errnum = ERR_NUMBER_OVERFLOW;
	  return 0;
	}
      myint = (myint * mult) + digit;
      ptr++;
    }

  if (!found)
    {
      errnum = ERR_NUMBER_PARSING;
      return 0;
    }

  *str_ptr = ptr;
  *myint_ptr = myint;

  return 1;
}
#endif /* STAGE1_5 */

#if !defined(STAGE1_5) || defined(FSYS_FAT)
int
grub_tolower (int c)
{
  if (c >= 'A' && c <= 'Z')
    return (c + ('a' - 'A'));

  return c;
}
#endif /* ! STAGE1_5 || FSYS_FAT */

int
grub_isspace (int c)
{
  switch (c)
    {
    case ' ':
    case '\t':
    case '\r':
    case '\n':
      return 1;
    default:
      break;
    }

  return 0;
}

#if !defined(STAGE1_5) || defined(FSYS_ISO9660)
int
grub_memcmp (const char *s1, const char *s2, int n)
{
  while (n)
    {
      if (*s1 < *s2)
	return -1;
      else if (*s1 > *s2)
	return 1;
      s1++;
      s2++;
      n--;
    }

  return 0;
}
#endif /* ! STAGE1_5 || FSYS_ISO9660 */

#ifndef STAGE1_5
int
grub_strncat (char *s1, const char *s2, int n)
{
  int i = -1;

  while (++i < n && s1[i] != 0);

  while (i < n && (s1[i++] = *(s2++)) != 0);

  s1[n - 1] = 0;

  if (i >= n)
    return 0;

  s1[i] = 0;

  return 1;
}
#endif /* ! STAGE1_5 */

/* XXX: This below is an evil hack. Certainly, we should change the
   strategy to determine what should be defined and what shouldn't be
   defined for each image. For example, it would be better to create
   a static library supporting minimal standard C functions and link
   each image with the library. Complicated things should be left to
   computer, definitely. -okuji  */
#if !defined(STAGE1_5) || defined(FSYS_VSTAFS)
int
grub_strcmp (const char *s1, const char *s2)
{
  while (*s1 || *s2)
    {
      if (*s1 < *s2)
	return -1;
      else if (*s1 > *s2)
	return 1;
      s1 ++;
      s2 ++;
    }

  return 0;
}
#endif /* ! STAGE1_5 || FSYS_VSTAFS */

#ifndef STAGE1_5
/* Wait for a keypress and return its code.  */
int
getkey (void)
{
  return current_term->getkey ();
}

/* Check if a key code is available.  */
int
checkkey (void)
{
  return current_term->checkkey ();
}
#endif /* ! STAGE1_5 */

/* Display an ASCII character.  */
void
grub_putchar (int c)
{
  if (c == '\n')
    grub_putchar ('\r');
#ifndef STAGE1_5
  else if (c == '\t' && current_term->getxy)
    {
      int n;
      
      n = 8 - ((current_term->getxy () >> 8) & 3);
      while (n--)
	grub_putchar (' ');
      
      return;
    }
#endif /* ! STAGE1_5 */
  
#ifdef STAGE1_5
  
  /* In Stage 1.5, only the normal console is supported.  */
  console_putchar (c);
  
#else /* ! STAGE1_5 */

  if (c == '\n')
    {
      /* Internal `more'-like feature.  */
      if (count_lines >= 0)
	{
	  count_lines++;
	  if (count_lines >= max_lines - 2)
	    {
	      int tmp;
	      
	      /* It's important to disable the feature temporarily, because
		 the following grub_printf call will print newlines.  */
	      count_lines = -1;

	      if (current_term->setcolorstate)
		current_term->setcolorstate (COLOR_STATE_HIGHLIGHT);
	      
	      grub_printf ("\n[Hit return to continue]");

	      if (current_term->setcolorstate)
		current_term->setcolorstate (COLOR_STATE_NORMAL);
	      
	      do
		{
		  tmp = ASCII_CHAR (getkey ());
		}
	      while (tmp != '\n' && tmp != '\r');
	      grub_printf ("\r                        \r");
	      
	      /* Restart to count lines.  */
	      count_lines = 0;
	      return;
	    }
	}
    }

  current_term->putchar (c);
  
#endif /* ! STAGE1_5 */
}

#ifndef STAGE1_5
void
gotoxy (int x, int y)
{
  current_term->gotoxy (x, y);
}

int
getxy (void)
{
  return current_term->getxy ();
}

void
cls (void)
{
  /* If the terminal is dumb, there is no way to clean the terminal.  */
  if (current_term->flags & TERM_DUMB)
    grub_putchar ('\n');
  else
    current_term->cls ();
}

int
setcursor (int on)
{
  if (current_term->setcursor)
    return current_term->setcursor (on);

  return 1;
}
#endif /* ! STAGE1_5 */

int
substring (const char *s1, const char *s2)
{
  while (*s1 == *s2)
    {
      /* The strings match exactly. */
      if (! *(s1++))
	return 0;
      s2 ++;
    }

  /* S1 is a substring of S2. */
  if (*s1 == 0)
    return -1;

  /* S1 isn't a substring. */
  return 1;
}

#ifndef STAGE1_5
/* Terminate the string STR with NUL.  */
int
nul_terminate (char *str)
{
  int ch;
  
  while (*str && ! grub_isspace (*str))
    str++;

  ch = *str;
  *str = 0;
  return ch;
}

char *
grub_strstr (const char *s1, const char *s2)
{
  while (*s1)
    {
      const char *ptr, *tmp;

      ptr = s1;
      tmp = s2;

      while (*tmp && *ptr == *tmp)
	ptr++, tmp++;
      
      if (tmp > s2 && ! *tmp)
	return (char *) s1;

      s1++;
    }

  return 0;
}

int
grub_strlen (const char *str)
{
  int len = 0;

  while (*str++)
    len++;

  return len;
}
#endif /* ! STAGE1_5 */

int
memcheck (int addr, int len)
{
#ifdef GRUB_UTIL
  static int start_addr (void)
    {
      int ret;
# if defined(HAVE_START_SYMBOL)
      asm volatile ("movl	$start, %0" : "=a" (ret));
# elif defined(HAVE_USCORE_START_SYMBOL)
      asm volatile ("movl	$_start, %0" : "=a" (ret));
# endif
      return ret;
    }

  static int end_addr (void)
    {
      int ret;
# if defined(HAVE_END_SYMBOL)
      asm volatile ("movl	$end, %0" : "=a" (ret));
# elif defined(HAVE_USCORE_END_SYMBOL)
      asm volatile ("movl	$_end, %0" : "=a" (ret));
# endif
      return ret;
    }

  if (start_addr () <= addr && end_addr () > addr + len)
    return ! errnum;
#endif /* GRUB_UTIL */

  if ((addr < RAW_ADDR (0x1000))
      || (addr < RAW_ADDR (0x100000)
	  && RAW_ADDR (mbi.mem_lower * 1024) < (addr + len))
      || (addr >= RAW_ADDR (0x100000)
	  && RAW_ADDR (mbi.mem_upper * 1024) < ((addr - 0x100000) + len)))
    errnum = ERR_WONT_FIT;

  return ! errnum;
}

void *
grub_memmove (void *to, const void *from, int len)
{
   if (memcheck ((int) to, len))
     {
       /* This assembly code is stolen from
	  linux-2.2.2/include/asm-i386/string.h. This is not very fast
	  but compact.  */
       int d0, d1, d2;

       if (to < from)
	 {
	   asm volatile ("cld\n\t"
			 "rep\n\t"
			 "movsb"
			 : "=&c" (d0), "=&S" (d1), "=&D" (d2)
			 : "0" (len),"1" (from),"2" (to)
			 : "memory");
	 }
       else
	 {
	   asm volatile ("std\n\t"
			 "rep\n\t"
			 "movsb\n\t"
			 "cld"
			 : "=&c" (d0), "=&S" (d1), "=&D" (d2)
			 : "0" (len),
			 "1" (len - 1 + (const char *) from),
			 "2" (len - 1 + (char *) to)
			 : "memory");
	 }
     }

   return errnum ? NULL : to;
}

void *
grub_memset (void *start, int c, int len)
{
  char *p = start;

  if (memcheck ((int) start, len))
    {
      while (len -- > 0)
	*p ++ = c;
    }

  return errnum ? NULL : start;
}

#ifndef STAGE1_5
char *
grub_strcpy (char *dest, const char *src)
{
  grub_memmove (dest, src, grub_strlen (src) + 1);
  return dest;
}
#endif /* ! STAGE1_5 */

#ifndef GRUB_UTIL
# undef memcpy
/* GCC emits references to memcpy() for struct copies etc.  */
void *memcpy (void *dest, const void *src, int n)  __attribute__ ((alias ("grub_memmove")));
#endif