grub/commands/i386/pc/vbe_list_modes.c

147 lines
3.7 KiB
C

/* vbe_list_modes.c - command to list compatible VBE video modes. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2005 Free Software Foundation, Inc.
*
* GRUB is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <grub/normal.h>
#include <grub/dl.h>
#include <grub/arg.h>
#include <grub/env.h>
#include <grub/misc.h>
#include <grub/machine/init.h>
#include <grub/machine/vbe.h>
static void *
real2pm(grub_vbe_farptr_t ptr)
{
return (void *)((((unsigned long)ptr & 0xFFFF0000) >> 12UL)
+ ((unsigned long)ptr & 0x0000FFFF));
}
static grub_err_t
grub_cmd_vbe_list_modes(struct grub_arg_list *state __attribute__ ((unused)),
int argc __attribute__ ((unused)),
char **args __attribute__ ((unused)))
{
struct grub_vbe_info_block controller_info;
struct grub_vbe_mode_info_block mode_info_tmp;
grub_uint32_t use_mode = GRUB_VBE_DEFAULT_VIDEO_MODE;
grub_uint16_t *sptr;
grub_uint32_t rc;
char *modevar;
grub_printf ("List of compatible video modes:\n");
rc = grub_vbe_probe (&controller_info);
if (rc != GRUB_ERR_NONE)
{
grub_printf ("VESA BIOS Extension not detected!\n");
return rc;
}
sptr = real2pm (controller_info.video_mode_ptr);
/* Walk thru all video modes listed. */
for (;*sptr != 0xFFFF; sptr++)
{
int valid_mode = 1;
rc = grub_vbe_get_video_mode_info (*sptr, &mode_info_tmp);
if (rc != GRUB_ERR_NONE) continue;
if ((mode_info_tmp.mode_attributes & 0x080) == 0)
{
/* We support only linear frame buffer modes. */
continue;
}
if ((mode_info_tmp.mode_attributes & 0x010) == 0)
{
/* We allow only graphical modes. */
continue;
}
switch(mode_info_tmp.memory_model)
{
case 0x04:
case 0x06:
break;
default:
valid_mode = 0;
break;
}
if (valid_mode == 0) continue;
grub_printf ("0x%03x: %d x %d x %d bpp\n",
*sptr,
mode_info_tmp.x_resolution,
mode_info_tmp.y_resolution,
mode_info_tmp.bits_per_pixel);
}
/* Check existence of vbe_mode environment variable. */
modevar = grub_env_get ("vbe_mode");
/* Check existence of vbe_mode environment variable. */
modevar = grub_env_get ("vbe_mode");
if (modevar != 0)
{
unsigned long value = 0;
if ((grub_strncmp (modevar, "0x", 2) == 0) ||
(grub_strncmp (modevar, "0X", 2) == 0))
{
/* Convert HEX mode number. */
value = grub_strtoul (modevar + 2, 0, 16);
}
else
{
/* Convert DEC mode number. */
value = grub_strtoul (modevar, 0, 10);
}
if (value != 0)
{
use_mode = value;
}
}
grub_printf ("Configured VBE mode (vbe_mode) = 0x%03x\n", use_mode);
return 0;
}
GRUB_MOD_INIT
{
(void)mod; /* To stop warning. */
grub_register_command ("vbe_list_modes",
grub_cmd_vbe_list_modes,
GRUB_COMMAND_FLAG_BOTH,
"vbe_list_modes",
"List compatible VESA BIOS extension video modes.",
0);
}
GRUB_MOD_FINI
{
grub_unregister_command ("vbe_list_modes");
}