kern/rescue_reader.c

   1 /* rescue_reader.c - rescue mode reader  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2009  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/types.h>
  21 #include <grub/reader.h>
  22 #include <grub/misc.h>
  23 #include <grub/term.h>
  24
  25 #define GRUB_RESCUE_BUF_SIZE    256
  26
  27 static char linebuf[GRUB_RESCUE_BUF_SIZE];
  28
  29 static grub_err_t
  30 grub_rescue_init (void)
  31 {
  32   grub_printf ("Entering rescue mode...\n");
  33   return 0;
  34 }
  35
  36 /* Prompt to input a command and read the line.  */
  37 static grub_err_t
  38 grub_rescue_read_line (char **line, int cont)
  39 {
  40   int c;
  41   int pos = 0;
  42
  43   grub_printf ((cont) ? "> " : "grub rescue> ");
  44   grub_memset (linebuf, 0, GRUB_RESCUE_BUF_SIZE);
  45
  46   while ((c = GRUB_TERM_ASCII_CHAR (grub_getkey ())) != '\n' && c != '\r')
  47     {
  48       if (grub_isprint (c))
  49         {
  50           if (pos < GRUB_RESCUE_BUF_SIZE - 1)
  51             {
  52               linebuf[pos++] = c;
  53               grub_putchar (c);
  54             }
  55         }
  56       else if (c == '\b')
  57         {
  58           if (pos > 0)
  59             {
  60               linebuf[--pos] = 0;
  61               grub_putchar (c);
  62               grub_putchar (' ');
  63               grub_putchar (c);
  64             }
  65         }
  66       grub_refresh ();
  67     }
  68
  69   grub_putchar ('\n');
  70   grub_refresh ();
  71
  72   *line = grub_strdup (linebuf);
  73
  74   return 0;
  75 }
  76
  77 static struct grub_reader grub_rescue_reader =
  78   {
  79     .name = "rescue",
  80     .init = grub_rescue_init,
  81     .read_line = grub_rescue_read_line
  82   };
  83
  84 void
  85 grub_register_rescue_reader (void)
  86 {
  87   grub_reader_register ("rescue", &grub_rescue_reader);
  88 }