vbatts/grub
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2008-02-03 Yoshinori K. Okuji <okuji@enbug.org>

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Add support for having a grub directory in a different drive. This
    is still only the data handling part.

    * kern/i386/pc/startup.S (multiboot_trampoline): Set %dh to 0xFF.
    (codestart): Save %dh in GRUB_ROOT_DRIVE.
    (grub_root_drive): New variable.

    * kern/i386/pc/init.c (make_install_device): Use GRUB_ROOT_DRIVE
    instead of GRUB_BOOT_DRIVE to construct a device name. Set
    GRUB_ROOT_DRIVE to GRUB_BOOT_DRIVE if it is 0xFF, otherwise use it
    as it was.

    * include/grub/i386/pc/kernel.h (grub_root_drive): New prototype.

    * include/grub/i386/pc/boot.h (GRUB_BOOT_MACHINE_ROOT_DRIVE): New
    macro.
    (GRUB_BOOT_MACHINE_DRIVE_CHECK): Set to 0x4f.

    * boot/i386/pc/pxeboot.S (_start): Set %dh to 0xFF. For now, this
    is bogus, because PXE booting does not specify any drive
    correctly.

    * boot/i386/pc/lnxboot.S (reg_edx): Set the second byte to 0xFF. I
    am not sure if this is really correct.

    * boot/i386/pc/cdboot.S: Set %dh to 0xFF, because the root drive
    is always identical to the boot drive when booting from a CD.

    * boot/i386/pc/boot.S (MOV_MEM_TO_AL): Removed. Not needed any
    longer.
    (root_drive): New variable.
    (real_start): Unconditionally set %dh to ROOT_DRIVE.
    (setup_sectors): Push %dx right after popping it, because %dh will
    be modified later.
    (copy_buffer): Restore %dx.
This commit is contained in:
okuji 2008-02-03 18:56:08 +00:00
parent e0ca067708
commit 9be6b98b6f
9 changed files with 78 additions and 15 deletions
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13
kern/i386/pc/init.c
View file

@ -72,13 +72,18 @@ make_install_device (void)
}
else if (grub_install_dos_part != -2)
{
if (grub_boot_drive >= GRUB_BIOSDISK_MACHINE_CDROM_START)
/* If the root drive is not set explicitly, assume that it is identical
to the boot drive. */
if (grub_root_drive == 0xFF)
grub_root_drive = grub_boot_drive;
if (grub_root_drive >= GRUB_BIOSDISK_MACHINE_CDROM_START)
grub_sprintf (dev, "(cd%u",
grub_boot_drive - GRUB_BIOSDISK_MACHINE_CDROM_START);
grub_root_drive - GRUB_BIOSDISK_MACHINE_CDROM_START);
else
grub_sprintf (dev, "(%cd%u",
(grub_boot_drive & 0x80) ? 'h' : 'f',
grub_boot_drive & 0x7f);
(grub_root_drive & 0x80) ? 'h' : 'f',
grub_root_drive & 0x7f);
if (grub_install_dos_part >= 0)
grub_sprintf (dev + grub_strlen (dev), ",%u", grub_install_dos_part + 1);

9
kern/i386/pc/startup.S
View file

@ -1,6 +1,6 @@
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 1999,2000,2001,2002,2003,2005,2006,2007 Free Software Foundation, Inc.
* Copyright (C) 1999,2000,2001,2002,2003,2005,2006,2007,2008 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
@ -162,6 +162,7 @@ multiboot_trampoline:
movl %ebx, EXT_C(grub_install_bsd_part)
2:
shrl $24, %edx
movb $0xFF, %dh
/* enter the usual booting */
call prot_to_real
.code16
@ -182,8 +183,9 @@ codestart:
sti /* we're safe again */
/* save boot drive reference */
/* save boot and root drive references */
ADDR32 movb %dl, EXT_C(grub_boot_drive)
ADDR32 movb %dh, EXT_C(grub_root_drive)
/* reset disk system (%ah = 0) */
int $0x13
@ -255,6 +257,9 @@ codestart:
VARIABLE(grub_boot_drive)
.long 0
VARIABLE(grub_root_drive)
.long 0
VARIABLE(grub_start_addr)
.long START_SYMBOL