| D.1. Linux Devices | ||
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Appendix D. Random Bits | 
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| D.1. Linux Devices | ||
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Appendix D. Random Bits |
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In Linux various special files can be found under the directory
/dev. These files are called device files and
behave unlike ordinary files. The most common types of device files
are for block devices and character devices. These files are an
interface to the actual driver (part of the Linux kernel) which in
turn accesses the hardware. Another, less common, type of device file
is the named pipe.
The most important device files are listed in the tables below.
sda |
First hard disk |
sdb |
Second hard disk |
sda1 |
First partition of the first hard disk |
sdb7 |
Seventh partition of the second hard disk |
sr0 |
First CD-ROM |
sr1 |
Second CD-ROM |
ttyS0 |
Serial port 0, COM1 under MS-DOS |
ttyS1 |
Serial port 1, COM2 under MS-DOS |
psaux |
PS/2 mouse device |
gpmdata |
Pseudo device, repeater data from GPM (mouse) daemon |
cdrom |
Symbolic link to the CD-ROM drive |
mouse |
Symbolic link to the mouse device file |
null |
Anything written to this device will disappear |
zero |
One can endlessly read zeros out of this device |
The mouse can be used in both the Linux console (with gpm) and the X
window environment. Normally, this is a simple matter of installing
gpm and the X server itself. Both should be
configured to use /dev/input/mice as the mouse
device. The correct mouse protocol is named exps2
in gpm, and ExplorerPS/2 in X. The respective
configuration files are /etc/gpm.conf and
/etc/X11/xorg.conf.
Certain kernel modules must be loaded in order for your mouse to work. In most cases the correct modules are autodetected, but not always for old-style serial and bus mice[20], which are quite rare except on very old computers. Summary of Linux kernel modules needed for different mouse types:
| Module | Description |
|---|---|
| psmouse | PS/2 mice (should be autodetected) |
| usbhid | USB mice (should be autodetected) |
| sermouse | Most serial mice |
| logibm | Bus mouse connected to Logitech adapter card |
| inport | Bus mouse connected to ATI or Microsoft InPort card |
To load a mouse driver module, you can use the modconf
command (from the package with the same name) and look in the category
kernel/drivers/input/mouse.
[20] Serial mice usually have a 9-hole D-shaped connector; bus mice have an 8-pin round connector, not to be confused with the 6-pin round connector of a PS/2 mouse or the 4-pin round connector of an ADB mouse.
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| Appendix D. Random Bits |  |
D.2. Disk Space Needed for Tasks |