Doing a BIOS update on recent Dell computers running linux is becoming really really easy, and is well integrated to the standard way to update software on linux distros using RPM and YUM. See this wiki page that helps to setup the dell yum repo. Do an initial invocation of bootstrap_firmware that'll enumerate the hardware of the machine that can possibly be updated through this method, pass the result of this command to yum, so the necessary firmware files will be downloaded, update the firmware, reboot, and voila! BIOS is up-to-date. No more proprietary MS-DOS executables, no more need to seek for an old bootable floppy with and even older copy of MS-DOS 6.22 on it.

[root@lxorgfr ~]# yum -y update
Loading "skip-broken" plugin
Loading "dellsysidplugin" plugin
fwupdate                  100% |=========================| 1.9 kB    00:00     
dell-software             100% |=========================| 1.9 kB    00:00     
fedora                    100% |=========================| 2.1 kB    00:00     
updates                   100% |=========================| 2.3 kB    00:00     
bellet                    100% |=========================| 2.1 kB    00:00     
Excluding Packages in global exclude list
Finished
Setting up Update Process
Resolving Dependencies
---> Running transaction check
---> Package openldap.i386 0:2.3.39-3.fc8 set to be updated
---> Package control-center-filesystem.i386 1:2.20.3-2.fc8 set to be updated
---> Package yum-utils.noarch 0:1.1.11-1.fc8 set to be updated
---> Package mesa-libGLU.i386 0:7.0.2-3.fc8 set to be updated
---> Package spamassassin.i386 0:3.2.4-1.fc8 set to be updated
---> Package shared-mime-info.i386 0:0.22-4.fc8 set to be updated
---> Package yum-skip-broken.noarch 0:1.1.11-1.fc8 set to be updated
---> Package system_bios_ven_0x1028_dev_0x0211.noarch 50:a07-20 set to be updated
---> Package xterm.i386 0:232-1.fc8 set to be updated
---> Package util-linux-ng.i386 0:2.13.1-1.fc8 set to be updated
---> Package mesa-libGL.i386 0:7.0.2-3.fc8 set to be updated
[...]
[root@lxorgfr ~]# update_firmware --yes

Searching storage directory for available BIOS updates...

Checking System BIOS for OptiPlex 755 - a05
        Available: system_bios(ven_0x1028_dev_0x0211) - a07
        Found Update: system_bios(ven_0x1028_dev_0x0211) - a07

Found firmware which needs to be updated.

Running updates...
 100% Installing system_bios(ven_0x1028_dev_0x0211) - a07
Done: Update complete. You must perform a warm reboot for the update to take effect.

[root@lxorgfr ~]# reboot

Broadcast message from root (pts/0) (Wed Feb 13 15:14:19 2008):

The system is going down for reboot NOW!
[root@lxorgfr ~]#

(et voila)