9be6b98b6f
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.
38 lines
1.2 KiB
ArmAsm
38 lines
1.2 KiB
ArmAsm
/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2000,2005,2007,2008 Free Software Foundation, Inc.
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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.file "pxeboot.S"
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.text
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/* Start with the prehistoric environment... */
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.code16
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/* Let's go */
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.globl _start; _start:
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/* Root drive will default to boot drive */
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movb $0xFF, %dh
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/* Jump to the real world */
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ljmp $0, $0x8200
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/* This region is a junk. Do you say that this is wasteful?
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But I like that the memory layout of the body is consistent
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among different kernels rather than scamping just for 1.5KB. */
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. = _start + 0x8200 - 0x7C00 - 0x200 - 1
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.byte 0
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