Chapter 2. The

proc

File System

29

2.2.10.

/proc/iomem

This file shows you the current map of the system's memory for each physical device:

00000000 0009fbff : System RAM

0009fc00 0009ffff : reserved

000a0000 000bffff : Video RAM area

000c0000 000c7fff : Video ROM

000f0000 000fffff : System ROM

00100000 07ffffff : System RAM

00100000 00291ba8 : Kernel code

00291ba9 002e09cb : Kernel data

e0000000 e3ffffff : VIA Technologies, Inc. VT82C597 [Apollo VP3]

e4000000 e7ffffff : PCI Bus #01

e4000000 e4003fff : Matrox Graphics, Inc. MGA G200 AGP

e5000000 e57fffff : Matrox Graphics, Inc. MGA G200 AGP

e8000000 e8ffffff : PCI Bus #01

e8000000 e8ffffff : Matrox Graphics, Inc. MGA G200 AGP

ea000000 ea00007f : Digital Equipment Corporation DECchip 21140 [FasterNet]

ea000000 ea00007f : tulip

ffff0000 ffffffff : reserved

The first column displays the memory registers used by each of the different types of memory. The

second column tells the kind of memory located within those registers. In particular, this column

will tell you which memory registers are used by the kernel within the system RAM or, if you have

multiple Ethernet ports on your NIC, the memory registers assigned for each port.

2.2.11.

/proc/ioports

The output of

/proc/ioports

provides a list of currently registered port regions used for input or

output communication with a device. This file can be quite long, with a beginning similar to this:

0000 001f : dma1

0020 003f : pic1

0040 005f : timer

0060 006f : keyboard

0070 007f : rtc

0080 008f : dma page reg

00a0 00bf : pic2

00c0 00df : dma2

00f0 00ff : fpu

0170 0177 : ide1

01f0 01f7 : ide0

02f8 02ff : serial(auto)

0376 0376 : ide1

03c0 03df : vga+

03f6 03f6 : ide0

03f8 03ff : serial(auto)

0cf8 0cff : PCI conf1

d000 dfff : PCI Bus #01

e000 e00f : VIA Technologies, Inc. Bus Master IDE

e000 e007 : ide0

e008 e00f : ide1

e800 e87f : Digital Equipment Corporation DECchip 21140 [FasterNet]

e800 e87f : tulip

The first column gives the IO port address range reserved for the device listed in the second column.