grub/grub-core/kern/main.c
2011-07-02 14:09:36 +02:00

246 lines
6.2 KiB
C

/* main.c - the kernel main routine */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2002,2003,2005,2006,2008,2009 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 3 of the License, or
* (at your option) any later version.
*
* GRUB 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, see <http://www.gnu.org/licenses/>.
*/
#include <grub/kernel.h>
#include <grub/misc.h>
#include <grub/symbol.h>
#include <grub/dl.h>
#include <grub/term.h>
#include <grub/file.h>
#include <grub/device.h>
#include <grub/env.h>
#include <grub/mm.h>
#include <grub/command.h>
#include <grub/reader.h>
#include <grub/parser.h>
void
grub_module_iterate (int (*hook) (struct grub_module_header *header))
{
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 (hook (header))
break;
}
}
/* This is actualy platform-independant but used only on loongson and sparc. */
#if defined (GRUB_MACHINE_MIPS_LOONGSON) || defined (GRUB_MACHINE_MIPS_QEMU_MIPS) || defined (GRUB_MACHINE_SPARC64)
grub_addr_t
grub_modules_get_end (void)
{
struct grub_module_info *modinfo;
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 modbase;
return modbase + modinfo->size;
}
#endif
/* Load all modules in core. */
static void
grub_load_modules (void)
{
auto int hook (struct grub_module_header *);
int hook (struct grub_module_header *header)
{
/* Not an ELF module, skip. */
if (header->type != OBJ_TYPE_ELF)
return 0;
if (! grub_dl_load_core ((char *) header + sizeof (struct grub_module_header),
(header->size - sizeof (struct grub_module_header))))
grub_fatal ("%s", grub_errmsg);
if (grub_errno)
grub_print_error ();
return 0;
}
grub_module_iterate (hook);
}
static void
grub_load_config (void)
{
auto int hook (struct grub_module_header *);
int hook (struct grub_module_header *header)
{
/* Not an embedded config, skip. */
if (header->type != OBJ_TYPE_CONFIG)
return 0;
grub_parser_execute ((char *) header +
sizeof (struct grub_module_header));
return 1;
}
grub_module_iterate (hook);
}
/* 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);
}
static void
grub_set_prefix_and_root (void)
{
char *device = NULL;
char *path = NULL;
char *fwdevice = NULL;
char *fwpath = NULL;
grub_register_variable_hook ("root", 0, grub_env_write_root);
{
char *pptr = NULL;
if (grub_prefix[0] == '(')
{
pptr = grub_strrchr (grub_prefix, ')');
if (pptr)
{
device = grub_strndup (grub_prefix + 1, pptr - grub_prefix - 1);
pptr++;
}
}
if (!pptr)
pptr = grub_prefix;
if (pptr[0])
path = grub_strdup (pptr);
}
if ((!device || device[0] == ',' || !device[0]) || !path)
grub_machine_get_bootlocation (&fwdevice, &fwpath);
if (!device && fwdevice)
device = fwdevice;
else if (fwdevice && (device[0] == ',' || !device[0]))
{
/* We have a partition, but still need to fill in the drive. */
char *comma, *new_device;
comma = grub_strchr (fwdevice, ',');
if (comma)
{
char *drive = grub_strndup (fwdevice, comma - fwdevice);
new_device = grub_xasprintf ("%s%s", drive, device);
grub_free (drive);
}
else
new_device = grub_xasprintf ("%s%s", fwdevice, device);
grub_free (fwdevice);
grub_free (device);
device = new_device;
}
if (fwpath && !path)
path = fwpath;
if (device)
{
char *prefix;
prefix = grub_xasprintf ("(%s)%s", device, path ? : "");
if (prefix)
{
grub_env_set ("prefix", prefix);
grub_free (prefix);
}
grub_env_set ("root", device);
}
grub_free (device);
grub_free (path);
grub_print_error ();
}
/* 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");
/* Something went wrong. Print errors here to let user know why we're entering rescue mode. */
grub_print_error ();
grub_errno = 0;
grub_command_execute ("normal", 0, 0);
}
/* 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 ();
#ifdef GRUB_LINKER_HAVE_INIT
grub_arch_dl_init_linker ();
#endif
grub_load_modules ();
/* It is better to set the root device as soon as possible,
for convenience. */
grub_set_prefix_and_root ();
grub_env_export ("root");
grub_env_export ("prefix");
grub_register_core_commands ();
grub_load_config ();
grub_load_normal_mode ();
grub_rescue_run ();
}