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grub/loader/i386/pc/linux.c

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/* linux.c - boot Linux zImage or bzImage */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 1999,2000,2001,2002,2003,2004,2005 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/loader.h>
#include <grub/machine/loader.h>
#include <grub/file.h>
#include <grub/err.h>
#include <grub/device.h>
#include <grub/disk.h>
#include <grub/misc.h>
#include <grub/types.h>
#include <grub/machine/init.h>
#include <grub/machine/memory.h>
#include <grub/rescue.h>
#include <grub/dl.h>
#include <grub/machine/linux.h>
static grub_dl_t my_mod;
static int big_linux;
static grub_size_t linux_mem_size;
static int loaded;
static grub_err_t
grub_linux_boot (void)
{
if (big_linux)
grub_linux_boot_bzimage ();
else
grub_linux_boot_zimage ();
/* Never reach here. */
return GRUB_ERR_NONE;
}
static grub_err_t
grub_linux_unload (void)
{
grub_dl_unref (my_mod);
loaded = 0;
return GRUB_ERR_NONE;
}
void
grub_rescue_cmd_linux (int argc, char *argv[])
{
grub_file_t file = 0;
struct linux_kernel_header lh;
grub_uint8_t setup_sects;
grub_size_t real_size, prot_size;
grub_ssize_t len;
int i;
char *dest;
grub_dl_ref (my_mod);
if (argc == 0)
{
grub_error (GRUB_ERR_BAD_ARGUMENT, "no kernel specified");
goto fail;
}
file = grub_file_open (argv[0]);
if (! file)
goto fail;
if (grub_file_size (file) > (grub_ssize_t) grub_os_area_size)
{
grub_error (GRUB_ERR_OUT_OF_RANGE, "too big kernel");
goto fail;
}
if (grub_file_read (file, (char *) &lh, sizeof (lh)) != sizeof (lh))
{
grub_error (GRUB_ERR_READ_ERROR, "cannot read the linux header");
goto fail;
}
if (lh.boot_flag != grub_cpu_to_le16 (0xaa55))
{
grub_error (GRUB_ERR_BAD_OS, "invalid magic number");
goto fail;
}
if (lh.setup_sects > GRUB_LINUX_MAX_SETUP_SECTS)
{
grub_error (GRUB_ERR_BAD_OS, "too many setup sectors");
goto fail;
}
big_linux = 0;
setup_sects = lh.setup_sects;
linux_mem_size = 0;
if (lh.header == grub_cpu_to_le32 (GRUB_LINUX_MAGIC_SIGNATURE)
&& grub_le_to_cpu16 (lh.version) >= 0x0200)
{
big_linux = (lh.loadflags & GRUB_LINUX_FLAG_BIG_KERNEL);
lh.type_of_loader = GRUB_LINUX_BOOT_LOADER_TYPE;
/* Put the real mode part at as a high location as possible. */
grub_linux_real_addr = (char *) (grub_lower_mem
- GRUB_LINUX_SETUP_MOVE_SIZE);
/* But it must not exceed the traditional area. */
if (grub_linux_real_addr > (char *) GRUB_LINUX_OLD_REAL_MODE_ADDR)
grub_linux_real_addr = (char *) GRUB_LINUX_OLD_REAL_MODE_ADDR;
if (grub_le_to_cpu16 (lh.version) >= 0x0201)
{
lh.heap_end_ptr = grub_cpu_to_le16 (GRUB_LINUX_HEAP_END_OFFSET);
lh.loadflags |= GRUB_LINUX_FLAG_CAN_USE_HEAP;
}
if (grub_le_to_cpu16 (lh.version) >= 0x0202)
lh.cmd_line_ptr = grub_linux_real_addr + GRUB_LINUX_CL_OFFSET;
else
{
lh.cl_magic = grub_cpu_to_le16 (GRUB_LINUX_CL_MAGIC);
lh.cl_offset = grub_cpu_to_le16 (GRUB_LINUX_CL_OFFSET);
lh.setup_move_size = grub_cpu_to_le16 (GRUB_LINUX_SETUP_MOVE_SIZE);
}
}
else
{
/* Your kernel is quite old... */
lh.cl_magic = grub_cpu_to_le16 (GRUB_LINUX_CL_MAGIC);
lh.cl_offset = grub_cpu_to_le16 (GRUB_LINUX_CL_OFFSET);
setup_sects = GRUB_LINUX_DEFAULT_SETUP_SECTS;
grub_linux_real_addr = (char *) GRUB_LINUX_OLD_REAL_MODE_ADDR;
}
/* If SETUP_SECTS is not set, set it to the default (4). */
if (! setup_sects)
setup_sects = GRUB_LINUX_DEFAULT_SETUP_SECTS;
real_size = setup_sects << GRUB_DISK_SECTOR_BITS;
prot_size = grub_file_size (file) - real_size - GRUB_DISK_SECTOR_SIZE;
grub_linux_tmp_addr = (char *) GRUB_LINUX_BZIMAGE_ADDR + prot_size;
if (! big_linux
&& prot_size > (grub_size_t) (grub_linux_real_addr
- (char *) GRUB_LINUX_ZIMAGE_ADDR))
{
grub_error (GRUB_ERR_BAD_OS, "too big zImage, use bzImage instead");
goto fail;
}
if (grub_linux_real_addr + GRUB_LINUX_SETUP_MOVE_SIZE
> (char *) grub_lower_mem)
{
grub_error (GRUB_ERR_OUT_OF_RANGE, "too small lower memory");
goto fail;
}
grub_printf (" [Linux-%s, setup=0x%x, size=0x%x]\n",
big_linux ? "bzImage" : "zImage", real_size, prot_size);
for (i = 1; i < argc; i++)
if (grub_memcmp (argv[i], "vga=", 4) == 0)
{
/* Video mode selection support. */
grub_uint16_t vid_mode;
char *val = argv[i] + 4;
if (grub_strcmp (val, "normal") == 0)
vid_mode = GRUB_LINUX_VID_MODE_NORMAL;
else if (grub_strcmp (val, "ext") == 0)
vid_mode = GRUB_LINUX_VID_MODE_EXTENDED;
else if (grub_strcmp (val, "ask") == 0)
vid_mode = GRUB_LINUX_VID_MODE_ASK;
else
vid_mode = (grub_uint16_t) grub_strtoul (val, 0, 0);
if (grub_errno)
goto fail;
lh.vid_mode = grub_cpu_to_le16 (vid_mode);
}
else if (grub_memcmp (argv[i], "mem=", 4) == 0)
{
char *val = argv[i] + 4;
linux_mem_size = grub_strtoul (val, &val, 0);
if (grub_errno)
{
grub_errno = GRUB_ERR_NONE;
linux_mem_size = 0;
}
else
{
int shift = 0;
switch (grub_tolower (val[0]))
{
case 'g':
shift += 10;
case 'm':
shift += 10;
case 'k':
shift += 10;
default:
break;
}
/* Check an overflow. */
if (linux_mem_size > (~0UL >> shift))
linux_mem_size = 0;
else
linux_mem_size <<= shift;
}
}
/* Put the real mode code at the temporary address. */
grub_memmove (grub_linux_tmp_addr, &lh, sizeof (lh));
len = real_size + GRUB_DISK_SECTOR_SIZE - sizeof (lh);
if (grub_file_read (file, grub_linux_tmp_addr + sizeof (lh), len) != len)
{
grub_error (GRUB_ERR_FILE_READ_ERROR, "Couldn't read file");
goto fail;
}
if (lh.header != grub_cpu_to_le32 (GRUB_LINUX_MAGIC_SIGNATURE)
|| grub_le_to_cpu16 (lh.version) < 0x0200)
/* Clear the heap space. */
grub_memset (grub_linux_tmp_addr
+ ((setup_sects + 1) << GRUB_DISK_SECTOR_BITS),
0,
((GRUB_LINUX_MAX_SETUP_SECTS - setup_sects - 1)
<< GRUB_DISK_SECTOR_BITS));
/* Specify the boot file. */
dest = grub_stpcpy (grub_linux_tmp_addr + GRUB_LINUX_CL_OFFSET,
"BOOT_IMAGE=");
dest = grub_stpcpy (dest, argv[0]);
/* Copy kernel parameters. */
for (i = 1;
i < argc
&& dest + grub_strlen (argv[i]) + 1 < (grub_linux_tmp_addr
+ GRUB_LINUX_CL_END_OFFSET);
i++)
{
*dest++ = ' ';
dest = grub_stpcpy (dest, argv[i]);
}
len = prot_size;
if (grub_file_read (file, (char *) GRUB_LINUX_BZIMAGE_ADDR, len) != len)
grub_error (GRUB_ERR_FILE_READ_ERROR, "Couldn't read file");
if (grub_errno == GRUB_ERR_NONE)
{
grub_linux_prot_size = prot_size;
grub_loader_set (grub_linux_boot, grub_linux_unload);
loaded = 1;
}
fail:
if (file)
grub_file_close (file);
if (grub_errno != GRUB_ERR_NONE)
{
grub_dl_unref (my_mod);
loaded = 0;
}
}
void
grub_rescue_cmd_initrd (int argc, char *argv[])
{
grub_file_t file = 0;
grub_ssize_t size;
grub_addr_t addr_max, addr_min, addr;
struct linux_kernel_header *lh;
if (argc == 0)
{
grub_error (GRUB_ERR_BAD_ARGUMENT, "No module specified");
goto fail;
}
if (!loaded)
{
grub_error (GRUB_ERR_BAD_ARGUMENT, "You need to load the kernel first.");
goto fail;
}
lh = (struct linux_kernel_header *) grub_linux_tmp_addr;
if (!(lh->header == grub_cpu_to_le32 (GRUB_LINUX_MAGIC_SIGNATURE)
&& grub_le_to_cpu16 (lh->version) >= 0x0200))
{
grub_error (GRUB_ERR_BAD_OS, "The kernel is too old for initrd.");
goto fail;
}
/* Get the highest address available for the initrd. */
if (grub_le_to_cpu16 (lh->version) >= 0x0203)
addr_max = grub_cpu_to_le32 (lh->initrd_addr_max);
else
addr_max = GRUB_LINUX_INITRD_MAX_ADDRESS;
if (!linux_mem_size && linux_mem_size < addr_max)
addr_max = linux_mem_size;
/* Linux 2.3.xx has a bug in the memory range check, so avoid
the last page.
Linux 2.2.xx has a bug in the memory range check, which is
worse than that of Linux 2.3.xx, so avoid the last 64kb. */
addr_max -= 0x10000;
if (addr_max > grub_os_area_addr + grub_os_area_size)
addr_max = grub_os_area_addr + grub_os_area_size;
addr_min = (grub_addr_t) grub_linux_tmp_addr + GRUB_LINUX_CL_END_OFFSET;
file = grub_file_open (argv[0]);
if (!file)
goto fail;
size = grub_file_size (file);
/* Put the initrd as high as possible, 4Ki aligned. */
addr = (addr_max - size) & ~0xFFF;
if (addr < addr_min)
{
grub_error (GRUB_ERR_OUT_OF_RANGE, "The initrd is too big");
goto fail;
}
if (grub_file_read (file, (void *)addr, size) != size)
{
grub_error (GRUB_ERR_FILE_READ_ERROR, "Couldn't read file");
goto fail;
}
lh->ramdisk_image = addr;
lh->ramdisk_size = size;
fail:
if (file)
grub_file_close (file);
}
GRUB_MOD_INIT(linux)
{
grub_rescue_register_command ("linux",
grub_rescue_cmd_linux,
"load linux");
grub_rescue_register_command ("initrd",
grub_rescue_cmd_initrd,
"load initrd");
my_mod = mod;
}
GRUB_MOD_FINI(linux)
{
grub_rescue_unregister_command ("linux");
grub_rescue_unregister_command ("initrd");
}
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