vbatts/grub
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

2005-07-17 Yoshinori Okuji <okuji@enbug.org>

Browse source 
* boot/i386/pc/boot.S (boot_drive_check): New label.

	* include/grub/i386/pc/boot.h (GRUB_BOOT_MACHINE_DRIVE_CHECK): New
	macro.

	* util/i386/pc/grub-setup.c (setup): Added a workaround for BIOSes
	which do not pass a boot drive correctly. Copied from GRUB Legacy.
This commit is contained in:
okuji 2005-07-17 14:57:07 +00:00
parent e293232b8e
commit f806d18efd
4 changed files with 42 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

17
boot/i386/pc/boot.S
View file

@ -1,7 +1,7 @@
/* -*-Asm-*- */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 1999,2000,2001,2002 Free Software Foundation, Inc.
* Copyright (C) 1999,2000,2001,2002,2005 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -108,6 +108,21 @@ after_BPB:
/* general setup */
cli /* we're not safe here! */
/*
* This is a workaround for buggy BIOSes which don't pass boot
* drive correctly. If GRUB is installed into a HDD, check if
* DL is masked correctly. If not, assume that the BIOS passed
* a bogus value and set DL to 0x80, since this is the only
* possible boot drive. If GRUB is installed into a floppy,
* this does nothing (only jump).
*/
boot_drive_check:
jmp 1f
testb $0x80, %dl
jnz 1f
movb $0x80, %dl
1:
/*
* ljmp to the next instruction because some bogus BIOSes
* jump to 07C0:0000 instead of 0000:7C00.