vbatts/grub
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity
grub/loader/i386/linux.c
robertmh 9c323f0961 2009-03-29 Robert Millan <rmh@aybabtu.com> 
* loader/i386/linux.c (grub_cmd_linux): Parse "vga=" parameter and
        set `vid_mode' accordingly.
        (grub_linux_boot): Process `vid_mode' and set video mode.
2009-03-29 19:52:35 +00:00

765 lines
19 KiB
C
Raw Blame History

/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2006,2007,2008,2009 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/loader.h>
#include <grub/machine/machine.h>
#include <grub/machine/memory.h>
#include <grub/machine/loader.h>
#include <grub/file.h>
#include <grub/disk.h>
#include <grub/err.h>
#include <grub/misc.h>
#include <grub/types.h>
#include <grub/dl.h>
#include <grub/mm.h>
#include <grub/term.h>
#include <grub/cpu/linux.h>
#include <grub/video.h>
/* FIXME: the definition of `struct grub_video_render_target' is
VBE-specific. */
#include <grub/i386/pc/vbe.h>
#include <grub/command.h>
#define GRUB_LINUX_CL_OFFSET 0x1000
#define GRUB_LINUX_CL_END_OFFSET 0x2000
static grub_dl_t my_mod;
static grub_size_t linux_mem_size;
static int loaded;
static void *real_mode_mem;
static void *prot_mode_mem;
static void *initrd_mem;
static grub_uint32_t real_mode_pages;
static grub_uint32_t prot_mode_pages;
static grub_uint32_t initrd_pages;
static grub_uint8_t gdt[] __attribute__ ((aligned(16))) =
{
/* NULL. */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* Reserved. */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* Code segment. */
0xFF, 0xFF, 0x00, 0x00, 0x00, 0x9A, 0xCF, 0x00,
/* Data segment. */
0xFF, 0xFF, 0x00, 0x00, 0x00, 0x92, 0xCF, 0x00
};
struct gdt_descriptor
{
grub_uint16_t limit;
void *base;
} __attribute__ ((packed));
static struct gdt_descriptor gdt_desc =
{
sizeof (gdt) - 1,
gdt
};
struct idt_descriptor
{
grub_uint16_t limit;
void *base;
} __attribute__ ((packed));
static struct idt_descriptor idt_desc =
{
0,
0
};
static grub_uint16_t vid_mode;
struct linux_vesafb_res
{
grub_uint16_t width;
grub_uint16_t height;
};
enum vga_modes
{
VGA_640_480,
VGA_800_600,
VGA_1024_768,
VGA_1280_1024,
};
struct linux_vesafb_mode
{
grub_uint8_t res_index;
grub_uint8_t depth;
};
static struct linux_vesafb_res linux_vesafb_res[] =
{
{ 640, 480 },
{ 800, 600 },
{ 1024, 768 },
{ 1280, 1024 }
};
/* This is the reverse of the table in [linux]/Documentation/fb/vesafb.txt. */
struct linux_vesafb_mode linux_vesafb_modes[] =
{
{ VGA_640_480, 8 }, /* 0x301 */
{ 0, 0 },
{ VGA_800_600, 8 }, /* 0x303 */
{ 0, 0 },
{ VGA_1024_768, 8 }, /* 0x305 */
{ 0, 0 },
{ VGA_1280_1024, 8 }, /* 0x307 */
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ VGA_640_480, 15 }, /* 0x310 */
{ VGA_640_480, 16 }, /* 0x311 */
{ VGA_640_480, 24 }, /* 0x312 */
{ VGA_800_600, 15 }, /* 0x313 */
{ VGA_800_600, 16 }, /* 0x314 */
{ VGA_800_600, 24 }, /* 0x315 */
{ VGA_1024_768, 15 }, /* 0x316 */
{ VGA_1024_768, 16 }, /* 0x317 */
{ VGA_1024_768, 24 }, /* 0x318 */
{ VGA_1280_1024, 15 }, /* 0x319 */
{ VGA_1280_1024, 16 }, /* 0x31a */
{ VGA_1280_1024, 24 }, /* 0x31b */
};
static inline grub_size_t
page_align (grub_size_t size)
{
return (size + (1 << 12) - 1) & (~((1 << 12) - 1));
}
/* Find the optimal number of pages for the memory map. */
static grub_size_t
find_mmap_size (void)
{
grub_size_t count = 0, mmap_size;
auto int NESTED_FUNC_ATTR hook (grub_uint64_t, grub_uint64_t, grub_uint32_t);
int NESTED_FUNC_ATTR hook (grub_uint64_t addr __attribute__ ((unused)),
grub_uint64_t size __attribute__ ((unused)),
grub_uint32_t type __attribute__ ((unused)))
{
count++;
return 0;
}
grub_machine_mmap_iterate (hook);
mmap_size = count * sizeof (struct grub_e820_mmap);
/* Increase the size a bit for safety, because GRUB allocates more on
later. */
mmap_size += (1 << 12);
return page_align (mmap_size);
}
static void
free_pages (void)
{
real_mode_mem = prot_mode_mem = initrd_mem = 0;
}
/* Allocate pages for the real mode code and the protected mode code
for linux as well as a memory map buffer. */
static int
allocate_pages (grub_size_t prot_size)
{
grub_size_t real_size, mmap_size;
/* Make sure that each size is aligned to a page boundary. */
real_size = GRUB_LINUX_CL_END_OFFSET;
prot_size = page_align (prot_size);
mmap_size = find_mmap_size ();
grub_dprintf ("linux", "real_size = %x, prot_size = %x, mmap_size = %x\n",
(unsigned) real_size, (unsigned) prot_size, (unsigned) mmap_size);
/* Calculate the number of pages; Combine the real mode code with
the memory map buffer for simplicity. */
real_mode_pages = ((real_size + mmap_size) >> 12);
prot_mode_pages = (prot_size >> 12);
/* Initialize the memory pointers with NULL for convenience. */
real_mode_mem = 0;
prot_mode_mem = 0;
/* FIXME: Should request low memory from the heap when this feature is
implemented. */
auto int NESTED_FUNC_ATTR hook (grub_uint64_t, grub_uint64_t, grub_uint32_t);
int NESTED_FUNC_ATTR hook (grub_uint64_t addr, grub_uint64_t size, grub_uint32_t type)
{
/* We must put real mode code in the traditional space. */
if (type == GRUB_MACHINE_MEMORY_AVAILABLE
&& addr <= 0x90000)
{
if (addr < 0x10000)
{
size += addr - 0x10000;
addr = 0x10000;
}
if (addr + size > 0x90000)
size = 0x90000 - addr;
if (real_size + mmap_size > size)
return 0;
real_mode_mem = (void *) ((addr + size) - (real_size + mmap_size));
return 1;
}
return 0;
}
grub_machine_mmap_iterate (hook);
if (! real_mode_mem)
{
grub_error (GRUB_ERR_OUT_OF_MEMORY, "cannot allocate real mode pages");
goto fail;
}
prot_mode_mem = (void *) 0x100000;
grub_dprintf ("linux", "real_mode_mem = %lx, real_mode_pages = %x, "
"prot_mode_mem = %lx, prot_mode_pages = %x\n",
(unsigned long) real_mode_mem, (unsigned) real_mode_pages,
(unsigned long) prot_mode_mem, (unsigned) prot_mode_pages);
return 1;
fail:
free_pages ();
return 0;
}
static void
grub_e820_add_region (struct grub_e820_mmap *e820_map, int *e820_num,
grub_uint64_t start, grub_uint64_t size,
grub_uint32_t type)
{
int n = *e820_num;
if (n >= GRUB_E820_MAX_ENTRY)
grub_fatal ("Too many e820 memory map entries");
if ((n > 0) && (e820_map[n - 1].addr + e820_map[n - 1].size == start) &&
(e820_map[n - 1].type == type))
e820_map[n - 1].size += size;
else
{
e820_map[n].addr = start;
e820_map[n].size = size;
e820_map[n].type = type;
(*e820_num)++;
}
}
static int
grub_linux_setup_video (struct linux_kernel_params *params)
{
struct grub_video_mode_info mode_info;
struct grub_video_render_target *render_target;
int ret;
ret = grub_video_get_info (&mode_info);
if (ret)
return 1;
ret = grub_video_get_active_render_target (&render_target);
if (ret)
return 1;
params->lfb_width = mode_info.width;
params->lfb_height = mode_info.height;
params->lfb_depth = mode_info.bpp;
params->lfb_line_len = mode_info.pitch;
params->lfb_base = (void *) render_target->data;
params->lfb_size = (params->lfb_line_len * params->lfb_height + 65535) >> 16;
params->red_mask_size = 8;
params->red_field_pos = 16;
params->green_mask_size = 8;
params->green_field_pos = 8;
params->blue_mask_size = 8;
params->blue_field_pos = 0;
params->reserved_mask_size = 8;
params->reserved_field_pos = 24;
return 0;
}
#ifdef __x86_64__
struct
{
grub_uint32_t kernel_entry;
grub_uint32_t kernel_cs;
} jumpvector;
#endif
static grub_err_t
grub_linux_boot (void)
{
struct linux_kernel_params *params;
int e820_num;
params = real_mode_mem;
if (vid_mode == GRUB_LINUX_VID_MODE_NORMAL || vid_mode == GRUB_LINUX_VID_MODE_EXTENDED)
grub_video_restore ();
else if (vid_mode)
{
struct linux_vesafb_mode *linux_mode;
int depth, flags;
flags = 0;
linux_mode = &linux_vesafb_modes[vid_mode - 0x301];
depth = linux_mode->depth;
/* If we have 8 or less bits, then assume that it is indexed color mode. */
if ((depth <= 8) && (depth != -1))
flags |= GRUB_VIDEO_MODE_TYPE_INDEX_COLOR;
/* We have more than 8 bits, then assume that it is RGB color mode. */
if (depth > 8)
flags |= GRUB_VIDEO_MODE_TYPE_RGB;
/* If user requested specific depth, forward that information to driver. */
if (depth != -1)
flags |= (depth << GRUB_VIDEO_MODE_TYPE_DEPTH_POS)
& GRUB_VIDEO_MODE_TYPE_DEPTH_MASK;
/* Try to initialize requested mode. */
if (grub_video_setup (linux_vesafb_res[linux_mode->res_index].width,
linux_vesafb_res[linux_mode->res_index].height,
flags) != GRUB_ERR_NONE)
{
grub_printf ("Unable to initialize requested video mode (vga=0x%x)\n", vid_mode);
return grub_errno;
}
}
if (! grub_linux_setup_video (params))
params->have_vga = GRUB_VIDEO_TYPE_VLFB;
else
{
params->have_vga = 0;
params->video_cursor_x = grub_getxy () >> 8;
params->video_cursor_y = grub_getxy () & 0xff;
params->video_width = 80;
params->video_height = 25;
}
grub_dprintf ("linux", "code32_start = %x, idt_desc = %lx, gdt_desc = %lx\n",
(unsigned) params->code32_start,
(unsigned long) &(idt_desc.limit),
(unsigned long) &(gdt_desc.limit));
grub_dprintf ("linux", "idt = %x:%lx, gdt = %x:%lx\n",
(unsigned) idt_desc.limit, (unsigned long) idt_desc.base,
(unsigned) gdt_desc.limit, (unsigned long) gdt_desc.base);
auto int NESTED_FUNC_ATTR hook (grub_uint64_t, grub_uint64_t, grub_uint32_t);
int NESTED_FUNC_ATTR hook (grub_uint64_t addr, grub_uint64_t size, grub_uint32_t type)
{
switch (type)
{
case GRUB_MACHINE_MEMORY_AVAILABLE:
grub_e820_add_region (params->e820_map, &e820_num,
addr, size, GRUB_E820_RAM);
break;
default:
grub_e820_add_region (params->e820_map, &e820_num,
addr, size, GRUB_E820_RESERVED);
}
return 0;
}
e820_num = 0;
grub_machine_mmap_iterate (hook);
params->mmap_size = e820_num;
/* Hardware interrupts are not safe any longer. */
asm volatile ("cli" : : );
/* Load the IDT and the GDT for the bootstrap. */
asm volatile ("lidt %0" : : "m" (idt_desc));
asm volatile ("lgdt %0" : : "m" (gdt_desc));
#ifdef __x86_64__
jumpvector.kernel_entry = (grub_uint64_t) grub_linux_real_boot;
jumpvector.kernel_cs = 0x10;
asm volatile ( "mov %0, %%rbx" : : "m" (params->code32_start));
asm volatile ( "mov %0, %%rsi" : : "m" (real_mode_mem));
asm volatile ( "ljmp *%0" : : "m" (jumpvector));
#else
/* Pass parameters. */
asm volatile ("movl %0, %%ecx" : : "m" (params->code32_start));
asm volatile ("movl %0, %%esi" : : "m" (real_mode_mem));
asm volatile ("xorl %%ebx, %%ebx" : : );
/* Enter Linux. */
asm volatile ("jmp *%%ecx" : : );
#endif
/* Never reach here. */
return GRUB_ERR_NONE;
}
static grub_err_t
grub_linux_unload (void)
{
free_pages ();
grub_dl_unref (my_mod);
loaded = 0;
return GRUB_ERR_NONE;
}
static grub_err_t
grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
int argc, char *argv[])
{
grub_file_t file = 0;
struct linux_kernel_header lh;
struct linux_kernel_params *params;
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_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;
}
/* FIXME: Is 2.02 recent enough for 32-bit boot? */
if (lh.header != grub_cpu_to_le32 (GRUB_LINUX_MAGIC_SIGNATURE)
|| grub_le_to_cpu16 (lh.version) < 0x0203)
{
grub_error (GRUB_ERR_BAD_OS, "too old version");
goto fail;
}
/* zImage doesn't support 32-bit boot. */
if (! (lh.loadflags & GRUB_LINUX_FLAG_BIG_KERNEL))
{
grub_error (GRUB_ERR_BAD_OS, "zImage is not supported");
goto fail;
}
setup_sects = lh.setup_sects;
/* 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;
if (! allocate_pages (prot_size))
goto fail;
params = (struct linux_kernel_params *) real_mode_mem;
grub_memset (params, 0, GRUB_LINUX_CL_END_OFFSET);
grub_memcpy (&params->setup_sects, &lh.setup_sects, sizeof (lh) - 0x1F1);
params->ps_mouse = params->padding10 = 0;
len = 0x400 - sizeof (lh);
if (grub_file_read (file, (char *) real_mode_mem + sizeof (lh), len) != len)
{
grub_error (GRUB_ERR_FILE_READ_ERROR, "Couldn't read file");
goto fail;
}
params->type_of_loader = (LINUX_LOADER_ID_GRUB << 4);
params->cl_magic = GRUB_LINUX_CL_MAGIC;
params->cl_offset = 0x1000;
params->cmd_line_ptr = (unsigned long) real_mode_mem + 0x1000;
params->ramdisk_image = 0;
params->ramdisk_size = 0;
params->heap_end_ptr = GRUB_LINUX_HEAP_END_OFFSET;
params->loadflags |= GRUB_LINUX_FLAG_CAN_USE_HEAP;
/* These are not needed to be precise, because Linux uses these values
only to raise an error when the decompression code cannot find good
space. */
params->ext_mem = ((32 * 0x100000) >> 10);
params->alt_mem = ((32 * 0x100000) >> 10);
params->video_page = 0; /* ??? */
params->video_mode = 0;
params->video_ega_bx = 0;
params->font_size = 16; /* XXX */
/* The other parameters are filled when booting. */
grub_file_seek (file, real_size + GRUB_DISK_SECTOR_SIZE);
grub_printf (" [Linux-bzImage, setup=0x%x, size=0x%x]\n",
(unsigned) real_size, (unsigned) prot_size);
/* Detect explicitly specified memory size, if any. */
linux_mem_size = 0;
for (i = 1; i < argc; i++)
if (grub_memcmp (argv[i], "vga=", 4) == 0)
{
/* Video mode selection support. */
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
vid_mode = (grub_uint16_t) grub_strtoul (val, 0, 0);
if (grub_errno)
goto fail;
}
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;
}
}
/* Specify the boot file. */
dest = grub_stpcpy ((char *) real_mode_mem + 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 < ((char *) real_mode_mem
+ 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_loader_set (grub_linux_boot, grub_linux_unload,
0 /* set noreturn=0 in order to avoid grub_console_fini() */);
loaded = 1;
}
fail:
if (file)
grub_file_close (file);
if (grub_errno != GRUB_ERR_NONE)
{
grub_dl_unref (my_mod);
loaded = 0;
}
return grub_errno;
}
static grub_err_t
grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
int argc, char *argv[])
{
grub_file_t file = 0;
grub_ssize_t size;
grub_addr_t addr_min, addr_max;
grub_addr_t 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;
}
file = grub_file_open (argv[0]);
if (! file)
goto fail;
size = grub_file_size (file);
initrd_pages = (page_align (size) >> 12);
lh = (struct linux_kernel_header *) real_mode_mem;
/* 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);
/* XXX in reality, Linux specifies a bogus value, so
it is necessary to make sure that ADDR_MAX does not exceed
0x3fffffff. */
if (addr_max > GRUB_LINUX_INITRD_MAX_ADDRESS)
addr_max = GRUB_LINUX_INITRD_MAX_ADDRESS;
}
else
addr_max = GRUB_LINUX_INITRD_MAX_ADDRESS;
if (linux_mem_size != 0 && 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;
/* Usually, the compression ratio is about 50%. */
addr_min = (grub_addr_t) prot_mode_mem + ((prot_mode_pages * 3) << 12)
+ page_align (size);
if (addr_max > grub_os_area_addr + grub_os_area_size)
addr_max = grub_os_area_addr + grub_os_area_size;
/* Put the initrd as high as possible, 4KiB aligned. */
addr = (addr_max - size) & ~0xFFF;
if (addr < addr_min)
{
grub_error (GRUB_ERR_OUT_OF_RANGE, "The initrd is too big");
goto fail;
}
initrd_mem = (void *) addr;
if (grub_file_read (file, initrd_mem, size) != size)
{
grub_error (GRUB_ERR_FILE_READ_ERROR, "Couldn't read file");
goto fail;
}
grub_printf (" [Initrd, addr=0x%x, size=0x%x]\n",
(unsigned) addr, (unsigned) size);
lh->ramdisk_image = addr;
lh->ramdisk_size = size;
lh->root_dev = 0x0100; /* XXX */
fail:
if (file)
grub_file_close (file);
return grub_errno;
}
static grub_command_t cmd_linux, cmd_initrd;
GRUB_MOD_INIT(linux)
{
cmd_linux = grub_register_command ("linux", grub_cmd_linux,
0, "load linux");
cmd_initrd = grub_register_command ("initrd", grub_cmd_initrd,
0, "load initrd");
my_mod = mod;
}
GRUB_MOD_FINI(linux)
{
grub_unregister_command (cmd_linux);
grub_unregister_command (cmd_initrd);
}
Reference in a new issue View git blame Copy permalink