arch/common/boot/grub2/font/manager.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2003,2005,2006,2007  Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <grub/file.h>
  20 #include <grub/misc.h>
  21 #include <grub/dl.h>
  22 #include <grub/normal.h>
  23 #include <grub/types.h>
  24 #include <grub/mm.h>
  25 #include <grub/font.h>
  26
  27 struct entry
  28 {
  29   grub_uint32_t code;
  30   grub_uint32_t offset;
  31 };
  32
  33 struct font
  34 {
  35   struct font *next;
  36   grub_file_t file;
  37   grub_uint32_t num;
  38   struct entry table[0];
  39 };
  40
  41 static struct font *font_list;
  42
  43 /* Fill unknown glyph's with rounded question mark.  */
  44 static grub_uint8_t unknown_glyph[16] =
  45 {       /* 76543210 */
  46   0x7C, /*  ooooo   */
  47   0x82, /* o     o  */
  48   0xBA, /* o ooo o  */
  49   0xAA, /* o o o o  */
  50   0xAA, /* o o o o  */
  51   0x8A, /* o   o o  */
  52   0x9A, /* o  oo o  */
  53   0x92, /* o  o  o  */
  54   0x92, /* o  o  o  */
  55   0x92, /* o  o  o  */
  56   0x92, /* o  o  o  */
  57   0x82, /* o     o  */
  58   0x92, /* o  o  o  */
  59   0x82, /* o     o  */
  60   0x7C, /*  ooooo   */
  61   0x00  /*          */
  62 };
  63
  64 static int
  65 add_font (const char *filename)
  66 {
  67   grub_file_t file = 0;
  68   char magic[4];
  69   grub_uint32_t num, i;
  70   struct font *font = 0;
  71
  72   file = grub_file_open (filename);
  73   if (! file)
  74     goto fail;
  75
  76   if (grub_file_read (file, magic, 4) != 4)
  77     goto fail;
  78
  79   if (grub_memcmp (magic, GRUB_FONT_MAGIC, 4) != 0)
  80     {
  81       grub_error (GRUB_ERR_BAD_FONT, "invalid font magic");
  82       goto fail;
  83     }
  84
  85   if (grub_file_read (file, (char *) &num, 4) != 4)
  86     goto fail;
  87
  88   num = grub_le_to_cpu32 (num);
  89   font = (struct font *) grub_malloc (sizeof (struct font)
  90                                       + sizeof (struct entry) * num);
  91   if (! font)
  92     goto fail;
  93
  94   font->file = file;
  95   font->num = num;
  96
  97   for (i = 0; i < num; i++)
  98     {
  99       grub_uint32_t code, offset;
 100
 101       if (grub_file_read (file, (char *) &code, 4) != 4)
 102         goto fail;
 103
 104       if (grub_file_read (file, (char *) &offset, 4) != 4)
 105         goto fail;
 106
 107       font->table[i].code = grub_le_to_cpu32 (code);
 108       font->table[i].offset = grub_le_to_cpu32 (offset);
 109     }
 110
 111   font->next = font_list;
 112   font_list = font;
 113
 114   return 1;
 115
 116  fail:
 117   if (font)
 118     grub_free (font);
 119
 120   if (file)
 121     grub_file_close (file);
 122
 123   return 0;
 124 }
 125
 126 static void
 127 remove_font (struct font *font)
 128 {
 129   struct font **p, *q;
 130
 131   for (p = &font_list, q = *p; q; p = &(q->next), q = q->next)
 132     if (q == font)
 133       {
 134         *p = q->next;
 135
 136         grub_file_close (font->file);
 137         grub_free (font);
 138
 139         break;
 140       }
 141 }
 142
 143 /* Return the offset of the glyph corresponding to the codepoint CODE
 144    in the font FONT.  If no found, return zero.  */
 145 static grub_uint32_t
 146 find_glyph (const struct font *font, grub_uint32_t code)
 147 {
 148   grub_uint32_t start = 0;
 149   grub_uint32_t end = font->num - 1;
 150   const struct entry *table = font->table;
 151
 152   /* This shouldn't happen.  */
 153   if (font->num == 0)
 154     return 0;
 155
 156   /* Do a binary search.  */
 157   while (start <= end)
 158     {
 159       grub_uint32_t i = (start + end) / 2;
 160
 161       if (table[i].code < code)
 162         start = i + 1;
 163       else if (table[i].code > code)
 164         end = i - 1;
 165       else
 166         return table[i].offset;
 167     }
 168
 169   return 0;
 170 }
 171
 172 /* Set the glyph to something stupid.  */
 173 static void
 174 fill_with_default_glyph (grub_font_glyph_t glyph)
 175 {
 176   unsigned i;
 177
 178   /* Use pre-defined pattern to fill unknown glyphs.  */
 179   for (i = 0; i < 16; i++)
 180     glyph->bitmap[i] = unknown_glyph[i];
 181
 182   glyph->char_width = 1;
 183   glyph->width = glyph->char_width * 8;
 184   glyph->height = 16;
 185   glyph->baseline = (16 * 3) / 4;
 186 }
 187
 188 /* Get a glyph corresponding to the codepoint CODE.  Always fill glyph
 189    information with something, even if no glyph is found.  */
 190 int
 191 grub_font_get_glyph (grub_uint32_t code,
 192                      grub_font_glyph_t glyph)
 193 {
 194   struct font *font;
 195   grub_uint8_t bitmap[32];
 196
 197   /* FIXME: It is necessary to cache glyphs!  */
 198
 199  restart:
 200   for (font = font_list; font; font = font->next)
 201     {
 202       grub_uint32_t offset;
 203
 204       offset = find_glyph (font, code);
 205       if (offset)
 206         {
 207           grub_uint32_t w;
 208           int len;
 209
 210           /* Make sure we can find glyphs for error messages.  Push active
 211              error message to error stack and reset error message.  */
 212           grub_error_push ();
 213
 214           grub_file_seek (font->file, offset);
 215           if ((len = grub_file_read (font->file, (char *) &w, sizeof (w)))
 216               != sizeof (w))
 217             {
 218               remove_font (font);
 219               goto restart;
 220             }
 221
 222           w = grub_le_to_cpu32 (w);
 223           if (w != 1 && w != 2)
 224             {
 225               /* grub_error (GRUB_ERR_BAD_FONT, "invalid width"); */
 226               remove_font (font);
 227               goto restart;
 228             }
 229
 230           if (grub_file_read (font->file, (char *) bitmap, w * 16)
 231               != (grub_ssize_t) w * 16)
 232             {
 233               remove_font (font);
 234               goto restart;
 235             }
 236
 237           /* Fill glyph with information.  */
 238           grub_memcpy (glyph->bitmap, bitmap, w * 16);
 239
 240           glyph->char_width = w;
 241           glyph->width = glyph->char_width * 8;
 242           glyph->height = 16;
 243           glyph->baseline = (16 * 3) / 4;
 244
 245           /* Restore old error message.  */
 246           grub_error_pop ();
 247
 248           return 1;
 249         }
 250     }
 251
 252   /* Uggh...  No font was found.  */
 253   fill_with_default_glyph (glyph);
 254   return 0;
 255 }
 256
 257 static grub_err_t
 258 font_command (struct grub_arg_list *state __attribute__ ((unused)),
 259               int argc  __attribute__ ((unused)),
 260               char **args __attribute__ ((unused)))
 261 {
 262   if (argc == 0)
 263     return grub_error (GRUB_ERR_BAD_ARGUMENT, "no font specified");
 264
 265   while (argc--)
 266     if (! add_font (*args++))
 267       return 1;
 268
 269   return 0;
 270 }
 271
 272 GRUB_MOD_INIT(font_manager)
 273 {
 274   grub_register_command ("font", font_command, GRUB_COMMAND_FLAG_BOTH,
 275                          "font FILE...",
 276                          "Specify one or more font files to display.", 0);
 277 }
 278
 279 GRUB_MOD_FINI(font_manager)
 280 {
 281   grub_unregister_command ("font");
 282 }