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Hi all. I have few questions on PCI. The first one is practical:

• - I can from the PCI configuration space by writing address of register I want to read to 0xCF8, and reading it from 0xCF8. On wiki page I found that I can write some configuration registers, but there's nothing about how what's the way to do it. Is it possible then? How can I do it?
  - Let's say I have graphic card connected to my computer via PCI. If I read BARs, can I get the memory or IO port for writing video memory? Or there's some special way and BARs are there only for some configurations?

Please help.

HugeCode wrote:Hi all. I have few questions on PCI. The first one is practical:

• - I can from the PCI configuration space by writing address of register I want to read to 0xCF8, and reading it from 0xCF8. On wiki page I found that I can write some configuration registers, but there's nothing about how what's the way to do it. Is it possible then? How can I do it?

1. outl [register index] to address register
2. in/out [data register]

HugeCode wrote:- Let's say I have graphic card connected to my computer via PCI. If I read BARs, can I get the memory or IO port for writing video memory? Or there's some special way and BARs are there only for some configurations?[/list]
Please help.

In theory every graphic card may be different, and you should check the device identity from configuration and don't touch any device you don't know about. Next, check the device's manual for supported interface(s), which may involve multiple BARs, and there are types of BAR to tell about io port number, address, and IRQ.

Thanks alot....