3.6. Pre-Installation Hardware and Operating System Setup
This section will walk you through pre-installation hardware setup, if
any, that you will need to do prior to installing Debian. Generally,
this involves checking and possibly changing firmware settings for
your system. The “firmware” is the core software used by the
hardware; it is most critically invoked during the bootstrap process
(after power-up). Known hardware issues affecting the reliability of
Debian GNU/Linux on your system are also highlighted.
3.6.1. Invoking the BIOS Set-Up Menu
BIOS provides the basic functions needed to boot your machine to allow
your operating system to access your hardware. Your system probably
provides a BIOS set-up menu, which is used to configure the BIOS.
Before installing, you must ensure that your BIOS
is setup correctly; not doing so can lead to intermittent crashes or
an inability to install Debian.
The rest of this section is lifted from the
https://www.faqs.org/faqs/pc-hardware-faq/part1/, answering the question, “How do I
enter the CMOS configuration menu?”. How you access the BIOS (or
“CMOS”) configuration menu depends on who wrote your BIOS
Some Intel x86 machines don't have a CMOS configuration menu in the
BIOS. They require a software CMOS setup program. If you don't have
the Installation and/or Diagnostics diskette for your machine, you can
try using a shareware/freeware program. Try looking in
3.6.2. Boot Device Selection
Many BIOS set-up menus allow you to select the devices that will be
used to bootstrap the system. Set this to look for a bootable
operating system on A: (the first floppy disk),
then optionally the first CD-ROM device (possibly appearing as
D: or E:), and then from
C: (the first hard disk). This setting enables
you to boot from either a floppy disk or a CD-ROM, which are the two
most common boot devices used to install Debian.
If you have a newer SCSI controller and you have a CD-ROM device
attached to it, you are usually able to boot from the CD-ROM. All you
have to do is enable booting from a CD-ROM in the SCSI-BIOS of your
Other popular option is to boot from a USB storage (also called USB
memory stick or USB key). Some BIOSes can boot USB storage directly,
and some cannot. You may need to configure your BIOS to boot from
a “Removable drive” or even a “USB-ZIP” to
get it to boot from the USB device.
Here are some details about how to set the boot order. Remember to
reset the boot order after Linux is installed, so that you restart
your machine from the hard drive.
18.104.22.168. Changing the Boot Order on IDE Computers
As your computer starts, press the keys to enter the BIOS
utility. Often, it is the Delete key. However,
consult the hardware documentation for the exact keystrokes.
Find the boot sequence in the setup utility. Its location depends on
your BIOS, but you are looking for a field that lists drives.
Common entries on IDE machines are C, A, cdrom or A, C, cdrom.
C is the hard drive, and A is the floppy drive.
Change the boot sequence setting so that the CD-ROM or the
floppy is first. Usually, the Page Up or
Page Down keys cycle
through the possible choices.
Save your changes. Instructions on the screen tell you how to
save the changes on your computer.
22.214.171.124. Changing the Boot Order on SCSI Computers
As your computer starts, press the keys to enter the SCSI setup
You can start the SCSI setup utility after the memory check and
the message about how to start the BIOS utility displays when you
start your computer.
The keystrokes you need depend on the utility. Often, it is
However, consult your hardware documentation for the
Find the utility for changing the boot order.
Set the utility so that the SCSI ID of the CD drive is first on
Save your changes. Instructions on the screen tell you how to
save the changes on your computer. Often, you must press
3.6.3. Miscellaneous BIOS Settings
126.96.36.199. CD-ROM Settings
Some BIOS systems (such as Award BIOS) allow you to automatically set
the CD speed. You should avoid that, and instead set it to, say, the
lowest speed. If you get seek failed error
messages, this may be your problem.
188.8.131.52. Extended vs. Expanded Memory
If your system provides both extended and
expanded memory, set it so that there is as much
extended and as little expanded memory as possible. Linux requires
extended memory and cannot use expanded memory.
184.108.40.206. Virus Protection
Disable any virus-warning features your BIOS may provide. If you have
a virus-protection board or other special hardware, make sure it is
disabled or physically removed while running GNU/Linux. These aren't
compatible with GNU/Linux; moreover, due to the file system
permissions and protected memory of the Linux kernel, viruses are
almost unheard of.
220.127.116.11. Shadow RAM
Your motherboard may provide shadow RAM or BIOS
caching. You may see settings for “Video BIOS Shadow”,
“C800-CBFF Shadow”, etc. Disable
all shadow RAM. Shadow
RAM is used to accelerate access to the ROMs on your motherboard and
on some of the controller cards. Linux does not use these ROMs once it
has booted because it provides its own faster 32-bit software in place
of the 16-bit programs in the ROMs. Disabling the shadow RAM may make
some of it available for programs to use as normal memory. Leaving
the shadow RAM enabled may interfere with Linux access to hardware
18.104.22.168. Memory Hole
If your BIOS offers something like “15–16 MB Memory
Hole”, please disable that. Linux expects to find memory there if
you have that much RAM.
We have a report of an Intel Endeavor motherboard on which there is an
option called “LFB” or “Linear Frame Buffer”.
This had two settings: “Disabled” and “1
Megabyte”. Set it to “1 Megabyte”.
When disabled, the installation floppy was not read correctly, and the
system eventually crashed. At this writing we don't understand what's
going on with this particular device — it just worked with that
setting and not without it.
22.214.171.124. Advanced Power Management
If your motherboard provides Advanced Power Management (APM),
configure it so that power management is controlled by APM. Disable
the doze, standby, suspend, nap, and sleep modes, and disable the hard
disk's power-down timer. Linux can take over control of these modes,
and can do a better job of power-management than the BIOS.
3.6.4. Hardware Issues to Watch Out For
Many people have tried operating their 90 MHz CPU at 100 MHz, etc. It
sometimes works, but is sensitive to temperature and other factors and
can actually damage your system. One of the authors of this document
over-clocked his own system for a year, and then the system started
aborting the gcc program with an unexpected signal
while it was compiling the operating system kernel. Turning the CPU
speed back down to its rated value solved the problem.
The gcc compiler is often the first thing to die
from bad memory modules (or other hardware problems that change data
unpredictably) because it builds huge data structures that it
traverses repeatedly. An error in these data structures will cause it
to execute an illegal instruction or access a non-existent
address. The symptom of this will be gcc dying from
an unexpected signal.
The very best motherboards support parity RAM and will actually tell
you if your system has a single-bit error in RAM. Unfortunately, they
don't have a way to fix the error, thus they generally crash
immediately after they tell you about the bad RAM. Still, it's better
to be told you have bad memory than to have it silently insert errors
in your data. Thus, the best systems have motherboards that support
parity and true-parity memory modules; see
Section 2.4.3, “Fake or “Virtual” Parity RAM”.
If you do have true-parity RAM and your motherboard can handle it, be
sure to enable any BIOS settings that cause the motherboard to
interrupt on memory parity errors.
126.96.36.199. The Turbo Switch
Many systems have a turbo switch that controls
the speed of the CPU. Select the high-speed setting. If your BIOS
allows you to disable software control of the turbo switch (or
software control of CPU speed), do so and lock the system in
high-speed mode. We have one report that on a particular system, while
Linux is auto-probing (looking for hardware devices) it can
accidentally touch the software control for the turbo switch.
188.8.131.52. Cyrix CPUs and Floppy Disk Errors
Many users of Cyrix CPUs have had to disable the cache in their
systems during installation, because the floppy disk has errors if
they do not. If you have to do this, be sure to re-enable your cache
when you are finished with installation, as the system runs
much slower with the cache disabled.
We don't think this is necessarily the fault of the Cyrix CPU. It may
be something that Linux can work around. We'll continue to look into
the problem. For the technically curious, we suspect a problem with
the cache being invalid after a switch from 16-bit to 32-bit code.
184.108.40.206. Peripheral Hardware Settings
You may have to change some settings or jumpers on your computer's
peripheral cards. Some cards have setup menus, while others rely on
jumpers. This document cannot hope to provide complete information on
every hardware device; what it hopes to provide is useful tips.
If any cards provide “mapped memory”, the memory should be
mapped somewhere between 0xA0000 and 0xFFFFF (from 640K to just below 1
megabyte) or at an address at least 1 megabyte greater than the total
amount of RAM in your system.
220.127.116.11. USB BIOS support and keyboards
If you have no AT-style keyboard and only a USB model, you may need
to enable legacy AT keyboard emulation in your BIOS setup. Only do this if
the installation system fails to use your keyboard in USB mode. Conversely,
for some systems (especially laptops) you may need to disable legacy USB
support if your keyboard does not respond.
Consult your main board manual and look in the BIOS for “Legacy
keyboard emulation” or “USB keyboard support” options.
After installation you can enable Boot Sector protection if you
want. This offers no additional security in Linux but if you also run
Windows it may prevent a catastrophe. There is no need to tamper with
the Master Boot Record (MBR) after the boot manager has been set up.