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Re: [PATCH] memdisk plus lnxboot extension
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From: |
Bean |
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Subject: |
Re: [PATCH] memdisk plus lnxboot extension |
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Date: |
Wed, 23 Jan 2008 00:22:32 +0800 |
On Jan 22, 2008 9:57 PM, Robert Millan <address@hidden> wrote:
> On Tue, Jan 22, 2008 at 12:25:49PM +0800, Bean wrote:
> > > but, what is the advantage in that? Is there any use case in which the
> > > first
> > > option is not good but the second is?
> >
> > Some advantages of using external initrd:
> >
> > 1, Resolve size limit for core.img
> > core.img can't be too large, otherwise it doesn't fit inside
> > conventional memory. external initrd doesn't have this problem.
>
> Ok.
>
> > 2. Easy to modify
> > users may not know how to create core.img, but modifying files in a,
> > say, tar or cpio archive is very easy. They can do simple tasks like
> > replacing splash image without too much knowledge of grub2.
> >
> > 3. Multiple configuration
> > We can use the same core.img, but different initrd to start grub2 with
> > different configuration.
>
> I don't think these two make a big difference, but well.
>
> No objection from me, then.
this is the patch, please try it.
* boot/i386/pc/lnxboot.S (data_start) : Simplify code.
(real_code_2) : Set grub_memdisk_image_addr using initrd address.
* include/grub/i386/pc/boot.h : New constant
GRUB_BOOT_MACHINE_LNX_LENG_OFFSET.
* include/grub/i386/pc/kernel.h : New constant
GRUB_KENRL_MACHINE_MEMDISK_IMAGE_ADDR.
New variable grub_memdisk_image_addr.
* kern/i386/pc/init.c (grub_arch_memdisk_addr) : Use
grub_memdisk_image_addr if it isn't zero.
* kern/i386/pc/startup.S : New variable grub_memdisk_image_addr.
* util/i386/pc/grub-mkimage.c (generate_image) : Add is_linux parameter.
If it's set, use lnxboot.img as header instead of diskboot.img.
(options): Add "linux"|'x' option
(main): Parse --linux|-x option, and pass its value to generate_image.
diff --git a/boot/i386/pc/lnxboot.S b/boot/i386/pc/lnxboot.S
index f1a4ded..6503e26 100644
--- a/boot/i386/pc/lnxboot.S
+++ b/boot/i386/pc/lnxboot.S
@@ -36,22 +36,7 @@
.globl start, _start
data_start:
- pushw %cs
- popw %ds
- xorl %eax, %eax
- xorl %ebx, %ebx
- call data_next
-
-data_next:
- popw %bx
- movw %cs, %ax
- shll $4, %eax
- leal 0x200 + data_start - data_next(%ebx,%eax), %eax
- movzbl setup_sects - data_next(%bx), %ecx
- shll $9, %ecx
- addl %ecx, %eax
- movl %eax, code32_start - data_next(%bx)
-
+ xorl %ebp, %ebp
jmp linux_next
. = data_start + 0x1F1
@@ -76,7 +61,7 @@ boot_flag:
start:
_start:
- jmp linux_code
+ jmp linux_init
.ascii "HdrS" // Header signature
.word 0x0203 // Header version number
@@ -134,9 +119,10 @@ reg_edx:
data_leng:
.long 0
-linux_code:
+linux_init:
movw %cs:(reg_edx - start), %dx
+ movl %cs:(code32_start - start), %ebp
linux_next:
@@ -164,9 +150,6 @@ real_code:
movw %si, %ss
movw $(CODE_ADDR), %sp
- pushl %esi
- pushl %edi
-
// Move itself to 0:CODE_ADDR
cld
@@ -183,17 +166,26 @@ real_code:
real_code_2:
+ xchgl %ebp, %esi
+ orl %esi, %esi
+ jnz 1f
+ movw %ds, %si
+ shll $4, %esi
+ addl %ebp, %esi
+1:
+
pushw %es
popw %ds
- movl (ramdisk_image - start), %esi
- or %esi, %esi
+ movl (data_leng - start), %ecx
+ or %ecx, %ecx
jnz 1f
- movl (code32_start - start), %esi
+ movl (ramdisk_image - start), %esi
+ movl (ramdisk_size - start), %ecx
+ addl $0x200, %esi
+ subl $0x200, %ecx
1:
- movl $0x200, %ecx
- addl %ecx, %esi
movl $DATA_ADDR, %edi
call move_memory
@@ -204,13 +196,17 @@ real_code_2:
movsbl (reg_edx + 2 - start), %eax
movl %eax, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_INSTALL_BSD_PART)
- movl %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_COMPRESSED_SIZE), %ecx
- addl $(GRUB_KERNEL_MACHINE_RAW_SIZE - 0x200), %ecx
+ movl (data_leng - start), %eax
+ or %eax, %eax
+ jz 1f
+ movl (ramdisk_size - start), %eax
+ or %eax, %eax
+ jz 1f
- call move_memory
-
- popl %edi
- popl %esi
+ movl %eax, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_MEMDISK_IMAGE_SIZE)
+ movl (ramdisk_image - start), %eax
+ movl %eax, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_MEMDISK_IMAGE_ADDR)
+1:
ljmp $(DATA_ADDR >> 4), $0
@@ -261,8 +257,8 @@ move_memory:
2:
- leal (%esi, %eax), %esi
- leal (%edi, %eax), %edi
+ addl %eax, %esi
+ addl %eax, %edi
subl %eax, %ecx
jnz 1b
diff --git a/include/grub/i386/pc/boot.h b/include/grub/i386/pc/boot.h
index fcc961b..4cc9a04 100644
--- a/include/grub/i386/pc/boot.h
+++ b/include/grub/i386/pc/boot.h
@@ -75,4 +75,7 @@
/* The size of a block list used in the kernel startup code. */
#define GRUB_BOOT_MACHINE_LIST_SIZE 12
+/* The offset of variable data_leng in lnxboot.S. */
+#define GRUB_BOOT_MACHINE_LNX_LENG_OFFSET 0x264
+
#endif /* ! BOOT_MACHINE_HEADER */
diff --git a/include/grub/i386/pc/kernel.h b/include/grub/i386/pc/kernel.h
index ca16df7..f5d8438 100644
--- a/include/grub/i386/pc/kernel.h
+++ b/include/grub/i386/pc/kernel.h
@@ -37,8 +37,11 @@
/* The offset of GRUB_MEMDISK_IMAGE_SIZE. */
#define GRUB_KERNEL_MACHINE_MEMDISK_IMAGE_SIZE 0x1c
+/* The offset of GRUB_MEMDISK_IMAGE_ADDR. */
+#define GRUB_KERNEL_MACHINE_MEMDISK_IMAGE_ADDR 0x20
+
/* The offset of GRUB_PREFIX. */
-#define GRUB_KERNEL_MACHINE_PREFIX 0x20
+#define GRUB_KERNEL_MACHINE_PREFIX 0x24
/* End of the data section. */
#define GRUB_KERNEL_MACHINE_DATA_END 0x50
@@ -66,6 +69,9 @@ extern grub_int32_t grub_install_bsd_part;
/* The size of memory disk image, if present. */
extern grub_int32_t grub_memdisk_image_size;
+/* The address of memory disk image, if present. */
+extern grub_int32_t grub_memdisk_image_addr;
+
/* The prefix which points to the directory where GRUB modules and its
configuration file are located. */
extern char grub_prefix[];
diff --git a/kern/i386/pc/init.c b/kern/i386/pc/init.c
index 0cf81d7..af6deda 100644
--- a/kern/i386/pc/init.c
+++ b/kern/i386/pc/init.c
@@ -253,9 +253,10 @@ grub_arch_modules_addr (void)
grub_addr_t
grub_arch_memdisk_addr (void)
{
- return GRUB_MEMORY_MACHINE_DECOMPRESSION_ADDR
+ return (grub_memdisk_image_addr) ? grub_memdisk_image_addr :
+ (GRUB_MEMORY_MACHINE_DECOMPRESSION_ADDR
+ (grub_kernel_image_size - GRUB_KERNEL_MACHINE_RAW_SIZE)
- + grub_total_module_size;
+ + grub_total_module_size);
}
/* Return the size of the memdisk image. */
diff --git a/kern/i386/pc/startup.S b/kern/i386/pc/startup.S
index e4101a6..5dd2e67 100644
--- a/kern/i386/pc/startup.S
+++ b/kern/i386/pc/startup.S
@@ -97,6 +97,8 @@ VARIABLE(grub_install_bsd_part)
.long 0xFFFFFFFF
VARIABLE(grub_memdisk_image_size)
.long 0
+VARIABLE(grub_memdisk_image_addr)
+ .long 0
VARIABLE(grub_prefix)
/* to be filled by grub-mkimage */
diff --git a/util/i386/pc/grub-mkimage.c b/util/i386/pc/grub-mkimage.c
index 48d6dfc..eee6b34 100644
--- a/util/i386/pc/grub-mkimage.c
+++ b/util/i386/pc/grub-mkimage.c
@@ -77,7 +77,7 @@ compress_kernel (char *kernel_img, size_t kernel_size,
}
static void
-generate_image (const char *dir, char *prefix, FILE *out, char
*mods[], char *memdisk_path)
+generate_image (const char *dir, char *prefix, FILE *out, char
*mods[], char *memdisk_path, int is_linux)
{
grub_addr_t module_addr = 0;
char *kernel_img, *boot_img, *core_img;
@@ -151,17 +151,25 @@ generate_image (const char *dir, char *prefix,
FILE *out, char *mods[], char *me
if (num > 0xffff)
grub_util_error ("the core image is too big");
- boot_path = grub_util_get_path (dir, "diskboot.img");
+ boot_path = grub_util_get_path (dir, (is_linux) ? "lnxboot.img" :
"diskboot.img");
boot_size = grub_util_get_image_size (boot_path);
- if (boot_size != GRUB_DISK_SECTOR_SIZE)
+ if ((! is_linux) && (boot_size != GRUB_DISK_SECTOR_SIZE))
grub_util_error ("diskboot.img is not one sector size");
boot_img = grub_util_read_image (boot_path);
- /* i386 is a little endian architecture. */
- *((grub_uint16_t *) (boot_img + GRUB_DISK_SECTOR_SIZE
+ if (is_linux)
+ {
+ *((grub_uint32_t *) (boot_img + GRUB_BOOT_MACHINE_LNX_LENG_OFFSET))
+ = grub_cpu_to_le32 (core_size);
+ }
+ else
+ {
+ /* i386 is a little endian architecture. */
+ *((grub_uint16_t *) (boot_img + GRUB_DISK_SECTOR_SIZE
- GRUB_BOOT_MACHINE_LIST_SIZE + 8))
- = grub_cpu_to_le16 (num);
+ = grub_cpu_to_le16 (num);
+ }
grub_util_write_image (boot_img, boot_size, out);
free (boot_img);
@@ -208,6 +216,7 @@ static struct option options[] =
{"prefix", required_argument, 0, 'p'},
{"memdisk", required_argument, 0, 'm'},
{"output", required_argument, 0, 'o'},
+ {"linux", no_argument, 0, 'x'},
{"help", no_argument, 0, 'h'},
{"version", no_argument, 0, 'V'},
{"verbose", no_argument, 0, 'v'},
@@ -229,6 +238,7 @@ Make a bootable image of GRUB.\n\
-p, --prefix=DIR set grub_prefix directory [default=%s]\n\
-m, --memdisk=FILE embed FILE as a memdisk image\n\
-o, --output=FILE output a generated image to FILE [default=stdout]\n\
+ -x, --linux add linux kernel header to output file\n\
-h, --help display this message and exit\n\
-V, --version print version information and exit\n\
-v, --verbose print verbose messages\n\
@@ -247,12 +257,13 @@ main (int argc, char *argv[])
char *prefix = NULL;
char *memdisk = NULL;
FILE *fp = stdout;
+ int is_linux = 0;
progname = "grub-mkimage";
while (1)
{
- int c = getopt_long (argc, argv, "d:p:m:o:hVv", options, 0);
+ int c = getopt_long (argc, argv, "d:p:m:o:xhVv", options, 0);
if (c == -1)
break;
@@ -280,6 +291,10 @@ main (int argc, char *argv[])
memdisk = xstrdup (optarg);
break;
+ case 'x':
+ is_linux = 1;
+ break;
+
case 'h':
usage (0);
break;
@@ -312,7 +327,7 @@ main (int argc, char *argv[])
grub_util_error ("cannot open %s", output);
}
- generate_image (dir ? : GRUB_LIBDIR, prefix ? : DEFAULT_DIRECTORY,
fp, argv + optind, memdisk);
+ generate_image (dir ? : GRUB_LIBDIR, prefix ? : DEFAULT_DIRECTORY,
fp, argv + optind, memdisk, is_linux);
fclose (fp);
--
Bean
- Re: [PATCH] memdisk plus lnxboot extension, Robert Millan, 2008/01/20
- Re: [PATCH] memdisk plus lnxboot extension, Marco Gerards, 2008/01/23
- Re: [PATCH] memdisk plus lnxboot extension, Bean, 2008/01/23
- Re: [PATCH] memdisk plus lnxboot extension, Bean, 2008/01/23
- Re: [PATCH] memdisk plus lnxboot extension, Robert Millan, 2008/01/23
- Re: [PATCH] memdisk plus lnxboot extension, Bean, 2008/01/23
- Re: [PATCH] memdisk plus lnxboot extension, Robert Millan, 2008/01/23
- Re: [PATCH] memdisk plus lnxboot extension, Bean, 2008/01/23