When first starts up, it writes many messages to the screen
which you might not be able to see. Linux maintains a special file,
called /proc/kmsg, which stores all these messages for later
viewing, and I've included a sample startup sequence here.
- The first thing Linux does is decides what type of video card
and screen you have, so it can pick a good font size. (The smaller the
font, the more that can fit on the screen on any one time.) Linux
may ask you if you want a special font, or it might have had a choice
compiled in.
In this example, the machine owner decided he wanted the standard,
large font at compile time. Also,
note the misspelling of the word ``color.'' Linus evidentally learned
the wrong version of English.
- Linux has now switched to protected mode, and the serial
driver has started to ask questions about the
hardware. A driver is a part of the kernel that controls a device,
usually a peripheral.
Here, it found 3 serial ports. A serial port is the equivalent of
a DOS COM port, and is a device normally used with
modems and mice.
What it is trying to say is that serial port 0 (COM1) has an
address of 0x03f8. When it interrupts the kernel,
usually to say that it has data, it uses IRQ 4. An IRQ is another
means of a peripheral talking to the software. Each serial port also
has a controller chip. The usual one for a port to have is a 16450;
other values possible are 8250 and 16550. The differences are beyond
the scope of this book.
- Next comes the parallel port driver. A parallel port is
normally connected to a printer, and the names for the parallel ports
(in ) start with lp. lp stands for Line
Printer, although it could be a laser printer.
That message says it has found one parallel port, and is using the
standard driver for it.
- The Linux kernel also tells you a little about memory usage:
This said that the machine had 8 megabytesmegabyte of
memory. Some of this memory was reserved for the kernel--just the
operating system. The rest of it could be used by programs.
The other type of ``memory'' is general called a hard
disk. It's like a large floppy disk permenantly in
your computer--the contents stay around even when the power is off.
- The kernel now moves onto looking at your floppy drives. In this
example, the machine has two drives. In DOS , drive ``A''
is a
inch drive, and drive
``B'' is a
inch drive.
Linux calls drive ``A'' fd0, and drive ``B'' fd1.
- Now Linux moves onto less needed things, such as network cards.
The following should be described in
The Linux Networking Guide, and is beyond the scope of this document.
- The next message you normally won't see as the machine boots up.
supports a FPU , a floating point unit. This is a
special chip (or part of a chip, in the case of a
80486DX CPUfloating point unit) that performs arithmetic
dealing with non-whole numbers. Some of these chips are bad, and
when tries to identify these chips, the machine ``crashes''.
That is to say, the machine stops functioning. If this happens,
you'll see:
Otherwise, you'll see:
if you're using a 486DX. If you are using a 386 with a 387, you'll see:
If you don't have any type of math coprocessor at all, you'll see:
- The kernel also scans for any hard disks you might have. If it
finds any (and it should) it'll look at what partitions you have on
them. A partition is a logical separation on a drive that is used
to keep operating systems from interfering with each other. In this
example, the computer had one hard disk (hda) with four
partitions.
- Finally, mounts the
root partition. The root partition is the disk partition where the
operating system resides. When
``mounts'' this partition, it is making the partition
available for use by the user.
