TITLE:		GRUB-Howto
LFS VERSION:	any
AUTHOR:		Fabio Fracassi <turiya@linuxfromscratch.org>

SYNOPSIS:
	GRUB is an alternative to LILO. This explains how to make it work.

HINT:
GRUB is the GNU GRand Unified Bootloader, a project which intends to
solve all bootup problems once and for all.

One of the most interesting features, is that you don't
have to install a new partition or kernel, you can change all parameters
at boottime via the GRUB Console, since it knows about the filesystems.

Let's get down to work:

	1. - Download: ftp://alpha.gnu.org/pub/gnu/grub/grub-0.91.tar.gz
	1b.- Download: http://linuxfromscratch.org/~gerard/grub-0.91-vga16.patch
		 This gives you support for a background picture in grub, 
		 if you want it
	2. - Extract: tar -xvzf grub-0.91.tar.gz
	2b.- Optionally apply th patch: patch -Np1 -i grub-0.91-vga16.patch
	3. - Install:
			./configure --prefix=/usr  # see INSTALL for further options
			make
			make install
	
			mkdir /boot/grub
			cp /usr/share/grub/i386-pc/stage1 /boot/grub
			cp /usr/share/grub/i386-pc/stage2 /boot/grub
		  And if you want copy one of the stage1.5 files, too (more later)
	4. - Starting Gurb:
		Now there are two ways of going on, you can start the GRUB Console
		via /usr/sbin/grub (which did not work too well for me :( )
		or via bootdisk:
			cd /boot/gurb
			cat stage1 stage2 >/dev/fd0 #Be sure to have an empty disk
						    # in your drive!
		Reboot!

	5. - Cofiguration:
		Now you have to define your setup:
		First GRUB wants to know on which partition it is installed
		GRUB names the partition as follows: (hd<BiosNr>,<PartitionNr>)
		i.e. /dev/hda is (hd0), /dev/hda1 (hd0,0), /dev/hdb2 (hd1,1), ...
		(I hope you get the clue ;) - else try man grub/info grub)

		if you dont know the partition you can issue a
			find /boot/grub/stage1
		on the GRUB Console
		
		Now you tell GRUB where it is installed:
			root (hd0,2)   # thats my setup (/dev/hda2)
		
		And install it in MBR
			setup (hd0) 


		If you want you can reboot now, and with
			kernel (hd0,1)/boot/bzImage root=/dev/hda2
                start your system.

		There is the posibility to "teach" GRUB knowlage of the filesystem,
		that way GRUB doesn't need a Blockmap for the stage2 file and is
		thus more robust against filesystem changes.
		This is arcived with the stage1.5 files:
		after issuing 
			root (hd0,1)
		type
			embed /boot/grub/reiserfs_stage1_5 (hd0) # or e2fs_stage1_5
		and note the number of sectors
		now issue 
			setup (hd0)
		or 
			install /boot/grub/stage1 (hd0) (hd0)1+<number of sectors embed returned> p /boot/grub/stage2 /boot/grub/menu.lst
		
		
	6. - Installing a Bootmenu:
		simply put a menu.lst file in the /boot/grub directory
		you can put most GRUB Console commands in there! (Check info grub!)

		Here is my setup for reference:

		# File /boot/grub/menu.lst - Bootmenu definition
		#
 
		# Start Entry 0 by default
		default 0
		timeout 10
 
		# makeing it nicer ;)
		color green/black light-green/black
 
		# If you have the Pixmap patch applied you can 
		# define a Background Picture here
		# The nice LFS image can be found at
		# http://linuxfromscratch.org/~gerard/lfslogos/lfs-grub-splash.xpm
		splashimage (hd0,1)/boot/grub/lfs-grub-splash.xpm
 
		#German keyboard
		setkey y z
		setkey z y
		setkey Y Z
		setkey Z Y
		setkey equal parenright
		setkey parenright parenleft
		setkey parenleft asterisk 
		setkey doublequote at
		setkey plus bracketright
		setkey minus slash
		setkey slash ampersand
		setkey ampersand percent
		setkey percent caret
		setkey underscore question
		setkey question underscore
		setkey semicolon less
		setkey less numbersign
		setkey numbersign backslash
		setkey colon greater
		setkey greater bar
		setkey asterisk braceright  
	
		#Standard Linux
		title LFS-Linux 2.4
		kernel (hd0,1)/boot/bzImage root=/dev/hda2
 
		#Old Linux
		title Old Suse Linux 6.4
		kernel (hd1,0)/bzImage root=/dev/hdb2
 
		#Windows 98
		title Windows 98
		chainloader (hd0,0)+1
 
		#install grup
		title (Re)Install grup
		root (hd0,1)
		embed /boot/grub/reiserfs_stage1_5
		install /boot/grub/stage1 (hd0) (hd0)1+19 p /boot/grub/stage2 /boot/grub/menu.lst                    


I think that gives you an idea how powerful a tool GRUB is, and
as you see not to difficult, too :)
The only problem I encouterd was, that the install/setup commands didn't
work from /usr/sbin/grub but I had no problems with the bootdisk.
I don't know much more about GRUB than what I wrote here check
the Documentation (especially info grub) for more information

Thanks to the German C't Magazin for the great article about GRUB

Update: 17/Apr/2002 Fabio Fracassi (turiya@linuxfromscratch.org)

Thanks to Gerard Beekmans for the Splashscreen Patch (and for LFS ;) )