In this post I am explaining the steps you can follow to boot from a DOS image using your grub to update the server’s BIOS version without the need of using a USB drive attached to your server.

To check your BIOS version in your server run this command:

$ sudo dmidecode --type bios # dmidecode 2.12 SMBIOS 2.6 present. Handle 0x0000, DMI type 0, 24 bytes BIOS Information Vendor: Dell Inc. Version: 1.12.0 Release Date: 07/30/2013 Address: 0xF0000 Runtime Size: 64 kB ROM Size: 4096 kB Characteristics: ISA is supported PCI is supported PNP is supported BIOS is upgradeable BIOS shadowing is allowed Boot from CD is supported Selectable boot is supported EDD is supported Japanese floppy for Toshiba 1.2 MB is supported (int 13h) 5.25"/360 kB floppy services are supported (int 13h) 5.25"/1.2 MB floppy services are supported (int 13h) 3.5"/720 kB floppy services are supported (int 13h) 8042 keyboard services are supported (int 9h) Serial services are supported (int 14h) CGA/mono video services are supported (int 10h) ACPI is supported USB legacy is supported BIOS boot specification is supported Function key-initiated network boot is supported Targeted content distribution is supported BIOS Revision: 1.12 Handle 0x0D00, DMI type 13, 22 bytes BIOS Language Information Language Description Format: Long Installable Languages: 1 en|US|iso8859-1 Currently Installed Language: en|US|iso8859-1

Now we are going to make a small bootable DOS system that we will use to boot in the server. I did the following steps in my own PC, but you can do them anywhere.

Install qemu if not installed yet to be able to install FreeDOS:

# apt-get update # apt-get install syslinux qemu-system-x86

You can download FreeDOS here http://www.freedos.org/download/

or just:

$ wget http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.0/fdbasecd.iso

Creaty an empty image of 250MB size:

dd if=/dev/zero of=fdos-250m-hdd.img bs=1M count=250

Launch qemu and install FreeDOS into the empty image:

qemu-system-x86_64 -hda fdos-250m-hdd.img -cdrom fdbasecd.iso -boot d

After installing FreeDOS you have to copy the BIOS updater tool to the image. To do that follow this steps:

~# fdisk -ul fdos-250m-hdd.img GNU Fdisk 1.2.5 Copyright (C) 1998 - 2006 Free Software Foundation, Inc. This program is free software, covered by the GNU General Public License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. Disk /home/user/fdos-250m-hdd.img: 261 MB, 261660672 bytes 16 heads, 63 sectors/track, 507 cylinders, total 511056 sectors Units = sectors of 1 * 512 = 512 bytes Device Boot Start End Blocks Id System /home/user/fdos-250m-hdd.img1 * 63 511055 255496 e FAT16 LBA

The partition starts at 63, so to get the offset, we have to multiply 63 by 512, 32256. To mount the partition you have to run this command:

~# mount -o loop,offset=32256 fdos-250m-hdd.img /mnt/

And copy the required tool:

~# mkdir /mnt/DELL ~# cp PER410-011200.exe /mnt/DELL/ ~# umount /mnt

Once you have your FreeDOS image ready, copy the image to your server to /boot/images. Create the directory /boot/images if it does not exist.

Prepare grub2 to use memdisk

$ sudo cp -a /usr/lib/syslinux/memdisk to /boot

Create the following file with your preferred editor:

~# cat /etc/grub.d/50_memdisk #!/bin/sh set -e IMAGES=/boot/images . /usr/lib/grub/grub-mkconfig_lib if test -e /boot/memdisk ; then MEMDISKPATH=$( make_system_path_relative_to_its_root "/boot/memdisk" ) echo "Found memdisk: $MEMDISKPATH" >&2 find $IMAGES -name "*.img" | sort | while read image ; do IMAGEPATH=$( make_system_path_relative_to_its_root "$image" ) echo "Found floppy image: $IMAGEPATH" >&2 cat << EOF menuentry "Bootable floppy: $(basename $IMAGEPATH | sed s/.img//)" { EOF prepare_grub_to_access_device ${GRUB_DEVICE_BOOT} | sed -e "s/^/\t/" cat << EOF linux16 $MEMDISKPATH bigraw initrd16 $IMAGEPATH } EOF done fi

And finally update grub with your new image:

$ sudo update-grub Generating grub configuration file ... Found linux image: /boot/vmlinuz-3.13.0-68-generic Found initrd image: /boot/initrd.img-3.13.0-68-generic Found memtest86+ image: /memtest86+.elf Found memtest86+ image: /memtest86+.bin Found memdisk: /memdisk Found floppy image: /images/fdos-250m-hdd.img done

Reboot and boot from your new image.