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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38
ChangeLog
View file

@ -1,3 +1,41 @@
2008-02-03 Yoshinori K. Okuji <okuji@enbug.org>
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.
2008-02-03 Robert Millan <rmh@aybabtu.com>
* util/i386/pc/grub-mkrescue.in: Rewrite most of image generation to

11
boot/i386/pc/boot.S
View file

@ -32,9 +32,6 @@
/* Print message string */
#define MSG(x) movw $ABS(x), %si; call message
/* XXX: binutils-2.9.1.0.x doesn't produce a short opcode for this. */
#define MOV_MEM_TO_AL(x) .byte 0xa0; .word x
.file "boot.S"
.text
@ -99,6 +96,8 @@ kernel_sector:
boot_drive:
.byte 0xff /* the disk to load kernel from */
/* 0xff means use the boot drive */
root_drive:
.byte 0xff
after_BPB:
@ -141,7 +140,9 @@ real_start:
/*
* Check if we have a forced disk reference here
*/
MOV_MEM_TO_AL(ABS(boot_drive)) /* movb ABS(boot_drive), %al */
/* assign root_drive at the same time */
movw ABS(boot_drive), %ax
movb %ah, %dh
cmpb $0xff, %al
je 1f
movb %al, %dl
@ -303,6 +304,7 @@ setup_sectors:
/* restore %dl */
popw %dx
pushw %dx
/* head start */
movb %al, %dh
@ -353,6 +355,7 @@ copy_buffer:
popw %ds
popa
popw %dx
/* boot kernel */
jmp *(kernel_address)

3
boot/i386/pc/cdboot.S
View file

@ -78,6 +78,9 @@ bi_reserved:
call read_cdrom
/* Root drive will default to boot drive */
movb $0xFF, %dh
ljmp $(DATA_ADDR >> 4), $0
/*

2
boot/i386/pc/lnxboot.S
View file

@ -115,7 +115,7 @@ gdt_dst2:
.long 0, 0, 0, 0 /* More space for the BIOS. */
reg_edx:
.byte 0x80,0,0xFF,0xFF
.byte 0x80, 0xFF, 0xFF, 0xFF
data_leng:
.long 0

5
boot/i386/pc/pxeboot.S
View file

@ -1,6 +1,6 @@
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2000,2005,2007 Free Software Foundation, Inc.
* Copyright (C) 2000,2005,2007,2008 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
@ -25,6 +25,9 @@
/* Let's go */
.globl _start; _start:
/* Root drive will default to boot drive */
movb $0xFF, %dh
/* Jump to the real world */
ljmp $0, $0x8200

7
include/grub/i386/pc/boot.h
View file

@ -1,6 +1,6 @@
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 1999,2000,2002,2005,2006,2007 Free Software Foundation, Inc.
* Copyright (C) 1999,2000,2002,2005,2006,2007,2008 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
@ -34,6 +34,9 @@
/* The offset of BOOT_DRIVE. */
#define GRUB_BOOT_MACHINE_BOOT_DRIVE 0x4c
/* The offset of ROOT_DRIVE. */
#define GRUB_BOOT_MACHINE_ROOT_DRIVE 0x4d
/* The offset of KERNEL_ADDRESS. */
#define GRUB_BOOT_MACHINE_KERNEL_ADDRESS 0x40
@ -44,7 +47,7 @@
#define GRUB_BOOT_MACHINE_KERNEL_SEGMENT 0x42
/* The offset of BOOT_DRIVE_CHECK. */
#define GRUB_BOOT_MACHINE_DRIVE_CHECK 0x4e
#define GRUB_BOOT_MACHINE_DRIVE_CHECK 0x4f
/* The offset of a magic number used by Windows NT. */
#define GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC 0x1b8

5
include/grub/i386/pc/kernel.h
View file

@ -1,6 +1,6 @@
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2002,2003,2007 Free Software Foundation, Inc.
* Copyright (C) 2002,2003,2007,2008 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
@ -73,6 +73,9 @@ extern char grub_prefix[];
/* The boot BIOS drive number. */
extern grub_int32_t grub_boot_drive;
/* The root BIOS drive number. */
extern grub_int32_t grub_root_drive;
/* The end address of the kernel. */
extern grub_addr_t grub_end_addr;

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