grub/kern/main.c

136 lines
3.7 KiB
C

/* main.c - the kernel main routine */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <grub/kernel.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/symbol.h>
#include <grub/dl.h>
#include <grub/term.h>
#include <grub/rescue.h>
#include <grub/file.h>
#include <grub/device.h>
#include <grub/env.h>
/* Load all modules in core. */
static void
grub_load_modules (void)
{
struct grub_module_info *modinfo;
struct grub_module_header *header;
grub_addr_t modbase;
modbase = grub_arch_modules_addr ();
modinfo = (struct grub_module_info *) modbase;
/* Check if there are any modules. */
if ((modinfo == 0) || modinfo->magic != GRUB_MODULE_MAGIC)
return;
for (header = (struct grub_module_header *) (modbase + modinfo->offset);
header < (struct grub_module_header *) (modbase + modinfo->size);
header = (struct grub_module_header *) ((char *) header + header->size))
{
if (! grub_dl_load_core ((char *) header + header->offset,
(header->size - header->offset)))
grub_fatal ("%s", grub_errmsg);
}
/* Add the region where modules reside into dynamic memory. */
grub_mm_init_region ((void *) modinfo, modinfo->size);
}
/* Write hook for the environment variables of root. Remove surrounding
parentheses, if any. */
static char *
grub_env_write_root (struct grub_env_var *var __attribute__ ((unused)),
const char *val)
{
/* XXX Is it better to check the existence of the device? */
grub_size_t len = grub_strlen (val);
if (val[0] == '(' && val[len - 1] == ')')
return grub_strndup (val + 1, len - 2);
return grub_strdup (val);
}
/* Set the root device according to the dl prefix. */
static void
grub_set_root_dev (void)
{
const char *prefix;
grub_register_variable_hook ("root", 0, grub_env_write_root);
prefix = grub_env_get ("prefix");
if (prefix)
{
char *dev;
dev = grub_file_get_device_name (prefix);
if (dev)
{
grub_env_set ("root", dev);
grub_free (dev);
}
}
}
/* Load the normal mode module and execute the normal mode if possible. */
static void
grub_load_normal_mode (void)
{
/* Load the module. */
grub_dl_load ("normal");
/* Ignore any error, because we have the rescue mode anyway. */
grub_errno = GRUB_ERR_NONE;
}
/* The main routine. */
void
grub_main (void)
{
/* First of all, initialize the machine. */
grub_machine_init ();
/* Hello. */
grub_setcolorstate (GRUB_TERM_COLOR_HIGHLIGHT);
grub_printf ("Welcome to GRUB!\n\n");
grub_setcolorstate (GRUB_TERM_COLOR_STANDARD);
/* Load pre-loaded modules and free the space. */
grub_register_exported_symbols ();
grub_load_modules ();
/* It is better to set the root device as soon as possible,
for convenience. */
grub_machine_set_prefix ();
grub_set_root_dev ();
/* Load the normal mode module. */
grub_load_normal_mode ();
/* Enter the rescue mode. */
grub_enter_rescue_mode ();
}