grub/commands/boot.c
2009-06-10 21:04:23 +00:00

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/* boot.c - command to boot an operating system */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2002,2003,2004,2005,2007,2009 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/normal.h>
#include <grub/dl.h>
#include <grub/misc.h>
#include <grub/loader.h>
#include <grub/kernel.h>
#include <grub/mm.h>
static grub_err_t (*grub_loader_boot_func) (void);
static grub_err_t (*grub_loader_unload_func) (void);
static int grub_loader_noreturn;
struct grub_preboot_t
{
grub_err_t (*preboot_func) (int);
grub_err_t (*preboot_rest_func) (void);
grub_loader_preboot_hook_prio_t prio;
struct grub_preboot_t *next;
struct grub_preboot_t *prev;
};
static int grub_loader_loaded;
static struct grub_preboot_t *preboots_head = 0,
*preboots_tail = 0;
int
grub_loader_is_loaded (void)
{
return grub_loader_loaded;
}
/* Register a preboot hook. */
void *
grub_loader_register_preboot_hook (grub_err_t (*preboot_func) (int noreturn),
grub_err_t (*preboot_rest_func) (void),
grub_loader_preboot_hook_prio_t prio)
{
struct grub_preboot_t *cur, *new_preboot;
if (! preboot_func && ! preboot_rest_func)
return 0;
new_preboot = (struct grub_preboot_t *)
grub_malloc (sizeof (struct grub_preboot_t));
if (! new_preboot)
{
grub_error (GRUB_ERR_OUT_OF_MEMORY, "hook not added");
return 0;
}
new_preboot->preboot_func = preboot_func;
new_preboot->preboot_rest_func = preboot_rest_func;
new_preboot->prio = prio;
for (cur = preboots_head; cur && cur->prio > prio; cur = cur->next);
if (cur)
{
new_preboot->next = cur;
new_preboot->prev = cur->prev;
cur->prev = new_preboot;
}
else
{
new_preboot->next = 0;
new_preboot->prev = preboots_tail;
preboots_tail = new_preboot;
}
if (new_preboot->prev)
new_preboot->prev->next = new_preboot;
else
preboots_head = new_preboot;
return new_preboot;
}
void
grub_loader_unregister_preboot_hook (void *hnd)
{
struct grub_preboot_t *preb = hnd;
if (preb->next)
preb->next->prev = preb->prev;
else
preboots_tail = preb->prev;
if (preb->prev)
preb->prev->next = preb->next;
else
preboots_head = preb->next;
grub_free (preb);
}
void
grub_loader_set (grub_err_t (*boot) (void),
grub_err_t (*unload) (void),
int noreturn)
{
if (grub_loader_loaded && grub_loader_unload_func)
grub_loader_unload_func ();
grub_loader_boot_func = boot;
grub_loader_unload_func = unload;
grub_loader_noreturn = noreturn;
grub_loader_loaded = 1;
}
void
grub_loader_unset(void)
{
if (grub_loader_loaded && grub_loader_unload_func)
grub_loader_unload_func ();
grub_loader_boot_func = 0;
grub_loader_unload_func = 0;
grub_loader_loaded = 0;
}
grub_err_t
grub_loader_boot (void)
{
grub_err_t err = GRUB_ERR_NONE;
struct grub_preboot_t *cur;
if (! grub_loader_loaded)
return grub_error (GRUB_ERR_NO_KERNEL, "no loaded kernel");
if (grub_loader_noreturn)
grub_machine_fini ();
for (cur = preboots_head; cur; cur = cur->next)
{
err = cur->preboot_func (grub_loader_noreturn);
if (err)
{
for (cur = cur->prev; cur; cur = cur->prev)
cur->preboot_rest_func ();
return err;
}
}
err = (grub_loader_boot_func) ();
for (cur = preboots_tail; cur; cur = cur->prev)
if (! err)
err = cur->preboot_rest_func ();
else
cur->preboot_rest_func ();
return err;
}
/* boot */
static grub_err_t
grub_cmd_boot (struct grub_command *cmd __attribute__ ((unused)),
int argc __attribute__ ((unused)),
char *argv[] __attribute__ ((unused)))
{
return grub_loader_boot ();
}
static grub_command_t cmd_boot;
GRUB_MOD_INIT(boot)
{
cmd_boot =
grub_register_command ("boot", grub_cmd_boot,
0, "boot an operating system");
}
GRUB_MOD_FINI(boot)
{
grub_unregister_command (cmd_boot);
}