GRUB Legacy: Difference between revisions

GRUB stands for GRand Unified Bootloader and is a [[bootloader]] and the reference implementation of the [[Multiboot|Multiboot Specification]]. GRUB can boot any Multiboot-compliant OS (e.g. Hurd, [http://grub.enbug.org/MultibootSystems among others]), however it can also boot some non-Multiboot-compliant OSes, e.g. Windows, via a chain-loading function, and some others via special support, e.g. Linux. mbchk can be used to determine if a file is Multiboot-compliant.

 

 

==Features==

Remove the boot disk from the floppy drive and insert the auxiliary disk. The files <code>stage1</code> and <code>stage2</code> from the GRUB distribution must be written to this disk, to sector 0 and sector 1+ respectively. In your shell (for Windows users, this means the [[Cygwin]] shell), type:

 

dd if=<stage1> of=/dev/fd0 bs=512 count=1

dd if=<stage2> of=/dev/fd0 bs=512 seek=1

 

Now GRUB will be able to boot stage1 and stage2 from this disk. We cannot use it as our boot disk, though, since writing stage2 to sector 1 destroyed the floppy's format structure (you can't write files to the disk anymore, and any previously written <code>boot</code> directory could no longer be found). That's why we will now set up the other disk to boot GRUB and have a valid structure.

GRUB will boot into its command shell. (If your system does boot from hard drive instead, check your BIOS boot drive settings.) When the <code>grub ></code> prompt appears, remove the auxiliary disk from the drive and replace the boot disk. From the GRUB shell, you can now complete the installation on the boot disk:

 

install (fd0)/boot/stage1 (fd0) (fd0)/boot/stage2 (fd0)/boot/menu.cfg

 

The parameters tell GRUB:

 

===Installing to USB===

'''NOTE''': I have tried many tools to install GRUB onto a USB device under windows, however, I have not been able to figure out how. So, to install, either use a Linux distro on your PC of use a Linux Live CD.

 

If you need to mount your USB device: (Exchange <code>sdb1</code> with your device name.)

 

mkdir /mnt/sdb1

mount /dev/sdb1 /mnt/sdb1

 

Create required directories:

 

mkdir /mnt/sdb1/boot

mkdir /mnt/sdb1/boot/grub

 

Locate the <code>stage1</code>, <code>stage2</code>, and <code>*_stage1_5</code> files:

 

find / -name stage1

 

Copy stage1 and stage2 files, <code>/usr/lib/grub/</code> is an example location, use the location returned by the find command:

 

cp /usr/lib/grub/stage1 /mnt/sdb1/boot/grub/stage1

cp /usr/lib/grub/stage2 /mnt/sdb1/boot/grub/stage2

 

For FAT formatted USB device use:

 

cp /usr/lib/grub/fat_stage1_5 /mnt/sdb1/boot/grub/fat_stage1_5

 

For ext2 formatted USB device use:

 

cp /usr/lib/grub/e2fs_stage_1_5 /mnt/sdb1/boot/grub/e2fs_stage_1_5

 

Then execute the GRUB install application:

 

sudo grub

 

Enter the following commands:

 

root (hd1,1)

setup (hd1)

quit

if you don't know where your kernel is, you can use the command "find /boot/grub/e2fs_stage_1_5" to get the parameters which would be used in the command root (sdb1,1) and setup (sdb1).

 

 

==Load your kernel over network (TFTP)==

You can also use GRUB's builtin network support to increase your build/test turn around time. You can boot another machine with a kernel directly from your build directory without having to copy it over manually. See also, [http://www.gnu.org/software/grub/manual/html_node/General-usage-of-network-support.html#General-usage-of-network-support How to set up your network] in the official GRUB manual.

 

Run

 

./configure --help

 

to see a list of options. In my case, I use Netgear tulip cards, so I execute:

 

./configure --enable-tulip

make

make install

 

You may want to consider using the <code>--prefix</code> option if you don't want to overwrite your existing GRUB install or do not have root access.

*[[Topic:9548|Switching back to real mode from GRUB]]

*[[Topic:9586|Setting boot-time graphic video mode with GRUB]]

 

===External Links===

 

[[Category:Bootloaders]]

[[de:Grand Unified Bootloader]]