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; on your system are also highlighted.
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.
Atari TT RAM boards are notorious for RAM problems under Linux; if you
encounter any strange problems, try running at least the kernel in
ST-RAM. Amiga users may need to exclude RAM using a booter memfile.
FIXME: more description of this needed.
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
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.
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.
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.
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.
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 tyour keyboard in USB mode. Consult
your main board manual and look in the BIOS for "Legacy keyboard
emulation" or "USB keyboard support" options.
More than 64 MB RAM
The Linux Kernel can not always detect what amount of RAM you have. If
this is the case please look at .