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Chapter 2. The

proc

File System

2.2.12.

/proc/isapnp

This file lists Plug and Play (PnP) cards in ISA slots on the system. This is most often seen with

sound cards but may include any number of devices. A

/proc/isapnp

file with Soundblaster entry

in it looks similar to this:

Card 1 'CTL0070:Creative ViBRA16C PnP' PnP version 1.0 Product version 1.0

Logical device 0 'CTL0001:Audio'

Device is not active

Active port 0x220,0x330,0x388

Active IRQ 5 [0x2]

Active DMA 1,5

Resources 0

Priority preferred

Port 0x220 0x220, align 0x0, size 0x10, 16 bit address decoding

Port 0x330 0x330, align 0x0, size 0x2, 16 bit address decoding

Port 0x388 0x3f8, align 0x0, size 0x4, 16 bit address decoding

IRQ 5 High Edge

DMA 1 8 bit byte count compatible

DMA 5 16 bit word count compatible

Alternate resources 0:1

Priority acceptable

Port 0x220 0x280, align 0x1f, size 0x10, 16 bit address decoding

Port 0x300 0x330, align 0x2f, size 0x2, 16 bit address decoding

Port 0x388 0x3f8, align 0x0, size 0x4, 16 bit address decoding

IRQ 5,7,2/9,10 High Edge

DMA 1,3 8 bit byte count compatible

DMA 5,7 16 bit word count compatible

This file can be quite long, depending on the number of devices displayed and their resource require 

ments.

Each card lists its name, PnP version number, and product version number. If the device is active

and configured, this file will also reveal the port and IRQ numbers for the device. In addition, to

ensure better compatibility, the card will specify

preferred

and

acceptable

values for a number

of different parameters. The goal here is to allow the PnP cards to work around one another and avoid

IRQ and port conflicts.

2.2.13.

/proc/kcore

This file represents the physical memory of the system and is stored in the core file format. Unlike

most

/proc/

files,

kcore

displays a size. This value is given in bytes and is equal to the size of

physical memory (RAM) used plus 4KB.

The contents of this file are designed to be examined by a debugger, such as

gdb

and is not human

readable.

Warning

Do not view the /proc/kcore virtual file. The contents of the file will scramble text output on the

terminal. If you accidentally view this file, press [Ctrl] [C] to stop the process then type reset to bring

back the command line prompt.