Chapter 7
Installing new hardware
Well, before I jump to the most exciting part of this book, I plan to give you a short introduction on how to install new hardware.
Installing the hardware
In this installation I will add two extra parallel ports to the system, again make sure that Linux supports the hardware or it won't work.
Sure you can use the hard drake, to detect your hardware and it probably will allow you to configure it right there from the control center. Here we will do it manually.
Step 1
- The first thing is getting resources for the parallel card
For ISA (Industry Standard Architecture)
If you are installing an ISA card, most likely resources are set by jumpers such as IRQs. Consult the manual if you have one.
For PCI (Peripheral Connection Interface)
For PCI, Linux can read and report these resources for all PCI cards. To see the resources type the following on your command line:
lspci –v | less
When this command is executed it will report all the resources being used by all PCI peripherals in the system.
Note: I suggest you run this command first before you physically install the hardware, and make note of what is installed, what IRQs are used by which devices and what addresses are used. Once you have this information, install your hardware and run the command again.
This is an example of a PCI Net card found in my system:
00:0f . 0 Ethernet controller: Realtek Semiconductor Co., Ltd
RTL-8139/8139C (rev 10)
Subsystem: Realtek Semiconductor Co., Ltd. RT8139
Flags: bus master, medium devsel, latency 66, IRQ 11
I/O Ports at 2400 [size=256]
Memory at 42000000 (32-bit, non-prefetchable) [size =256]
Capabilities: <available only to root>
The information above is what you get when you run the command, and what you really need from this information is: I/O and IRQ
I/O Ports at 2400
Flags: bus master, medium devsel, latency 66, IRQ 11
Let's assume that on this system we have a parallel port PCI at port address 0x6100 and IRQ 12.
We also have other two parallel ports at addresses:
- 0x6400 with IRQ 12 (port B)
- And 0x6500 with IRQ 12 (port C).
Make note that these addresses are in Hexadecimal. That is why it appears with the 0x. All hardware uses an address like this one; it is a reserved area exclusively for that piece of hardware. These addresses are used as a point of reference whenever the hardware needs to communicate to the processor or other devices in accordance with the IRQ (interrupt request).
DMA (direct memory access): Without this, the hardware is unable to communicate. But of course it can be modified and new ones can be assigned. Once these values have been defined, they stay permanently as long as the hardware exists in the system.
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