+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
/* 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
boot_drive:
.byte 0xff /* the disk to load kernel from */
/* 0xff means use the boot drive */
+root_drive:
+ .byte 0xff
after_BPB:
/*
* 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
/* restore %dl */
popw %dx
+ pushw %dx
/* head start */
movb %al, %dh
popw %ds
popa
+ popw %dx
/* boot kernel */
jmp *(kernel_address)
call read_cdrom
+ /* Root drive will default to boot drive */
+ movb $0xFF, %dh
+
ljmp $(DATA_ADDR >> 4), $0
/*
.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
/*
* 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
/* Let's go */
.globl _start; _start:
+ /* Root drive will default to boot drive */
+ movb $0xFF, %dh
+
/* Jump to the real world */
ljmp $0, $0x8200
/*
* 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
/* 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
#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
/*
* 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
/* 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;
}
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);
/*
* 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
movl %ebx, EXT_C(grub_install_bsd_part)
2:
shrl $24, %edx
+ movb $0xFF, %dh
/* enter the usual booting */
call prot_to_real
.code16
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
VARIABLE(grub_boot_drive)
.long 0
+VARIABLE(grub_root_drive)
+ .long 0
+
VARIABLE(grub_start_addr)
.long START_SYMBOL
projects / thirdparty / grub.git / commitdiff
