[PATCH 1/7] Make boot/i386/pc/boot.S safer to modify

[Pavel Roskin]

ChangeLog:

        * include/grub/i386/pc/boot.h: Sort all offsets.
        (GRUB_BOOT_MACHINE_KERNEL_ADDRESS): Remove, it's unused.
        (GRUB_BOOT_MACHINE_KERNEL_SEGMENT): Likewise.
        * boot/i386/pc/boot.S: Assert location of every offset listed in
        include/grub/i386/pc/boot.h.
---
 boot/i386/pc/boot.S         |    8 +++++++-
 include/grub/i386/pc/boot.h |   10 ++--------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/boot/i386/pc/boot.S b/boot/i386/pc/boot.S
index 8d8c27c..fb90947 100644
--- a/boot/i386/pc/boot.S
+++ b/boot/i386/pc/boot.S
@@ -65,6 +65,7 @@ start:
         * this area.
         */
 
+       . = _start + GRUB_BOOT_MACHINE_BPB_START
        . = _start + 4
 
        /* scratch space */
@@ -91,14 +92,19 @@ cylinder_start:
         * End of BIOS parameter block.
         */
 
+       . = _start + GRUB_BOOT_MACHINE_VER_MAJ
 boot_version:
        .byte   GRUB_BOOT_VERSION_MAJOR, GRUB_BOOT_VERSION_MINOR
 kernel_address:
        .word   GRUB_BOOT_MACHINE_KERNEL_ADDR
 kernel_segment:
        .word   GRUB_BOOT_MACHINE_KERNEL_SEG
+
+       . = _start + GRUB_BOOT_MACHINE_KERNEL_SECTOR
 kernel_sector:
        .long   1, 0
+
+       . = _start + GRUB_BOOT_MACHINE_BOOT_DRIVE
 boot_drive:
        .byte 0xff      /* the disk to load kernel from */
                        /* 0xff means use the boot drive */
@@ -477,8 +483,8 @@ nt_magic:
         *  sneaky, huh?
         */
 
-part_start:
        . = _start + GRUB_BOOT_MACHINE_PART_START
+part_start:
 
 probe_values:
        .byte   36, 18, 15, 9, 0
diff --git a/include/grub/i386/pc/boot.h b/include/grub/i386/pc/boot.h
index f35cb3a..221ed38 100644
--- a/include/grub/i386/pc/boot.h
+++ b/include/grub/i386/pc/boot.h
@@ -31,17 +31,11 @@
 /* The offset of the major version.  */
 #define GRUB_BOOT_MACHINE_VER_MAJ      0x3e
 
-/* The offset of BOOT_DRIVE.  */
-#define GRUB_BOOT_MACHINE_BOOT_DRIVE   0x4c
-
-/* The offset of KERNEL_ADDRESS.  */
-#define GRUB_BOOT_MACHINE_KERNEL_ADDRESS       0x40
-
 /* The offset of KERNEL_SECTOR.  */
 #define GRUB_BOOT_MACHINE_KERNEL_SECTOR        0x44
 
-/* The offset of KERNEL_SEGMENT.  */
-#define GRUB_BOOT_MACHINE_KERNEL_SEGMENT       0x42
+/* The offset of BOOT_DRIVE.  */
+#define GRUB_BOOT_MACHINE_BOOT_DRIVE   0x4c
 
 /* The offset of BOOT_DRIVE_CHECK.  */
 #define GRUB_BOOT_MACHINE_DRIVE_CHECK  0x4e