# Peripheral Component Interconnect

> Conventional PCI, often shortened to PCI, is a local computer bus for attaching hardware devices in a computer. PCI is the initialism for Peripheral Component Interconnect\[2] and is part of the PCI Local Bus standard. The PCI bus supports the functions found on a processor bus but in a standardized format that is independent of any particular processor's native bus. Devices connected to the PCI bus appear to a bus master to be connected directly to its own bus and are assigned addresses in the processor's address space. It is a parallel bus, synchronous to a single bus clock. Wikipedia

* [Wikipedia Peripheral Component Interconnect](https://es.wikipedia.org/wiki/Peripheral_Component_Interconnect)

## Kernel Integration

### Kernel Display Message

```bash
    root@edison:~# dmesg | grep -i pci
    [    0.000000] e820: [mem 0x40000000-0xfebfffff] available for PCI devices
    [    0.191609] PCI: MMCONFIG for domain 0000 [bus 00-00] at [mem 0x3f500000-0x3f5fffff] (base 0x3f500000)
    [    0.191633] PCI: MMCONFIG at [mem 0x3f500000-0x3f5fffff] reserved in E820
    [    0.191647] PCI: Using MMCONFIG for extended config space
    [    0.191660] PCI: Using configuration type 1 for base access
    [    0.214309] Intel MID platform detected, using MID PCI ops
    [    0.214322] PCI: Probing PCI hardware
    [    0.214337] PCI: root bus 00: using default resources
    [    0.214352] PCI: Probing PCI hardware (bus 00)
    [    0.214615] PCI host bridge to bus 0000:00
    ...
```

## Applications / Libraries

### Programs

> lspci
>
> > A command on Unix-like operating systems that prints ("lists") detailed information about all PCI buses and devices in the system. It is based on a common portable library libpci which offers access to the PCI configuration space on a variety of operating systems.

```bash
    root@edison:~# lspci
    00:00.0 Host bridge: Intel Corporation Device 1170 (rev 01)             
    00:01.0 SD Host controller: Intel Corporation Device 1190 (rev 01)      
    00:01.2 SD Host controller: Intel Corporation Device 1190 (rev 01)      
    00:01.3 SD Host controller: Intel Corporation Device 1190 (rev 01)         
    00:02.0 Display controller: Intel Corporation Device 1182 (rev 01)         
    00:04.0 Serial controller: Intel Corporation Device 1191 (rev 01)          
    00:04.1 Serial controller: Intel Corporation Device 1191 (rev 01)           
    00:04.2 Serial controller: Intel Corporation Device 1191 (rev 01)           
    00:04.3 Serial controller: Intel Corporation Device 1191 (rev 01)           
    00:05.0 Serial controller: Intel Corporation Device 1192 (rev 01)           
    00:06.0 System peripheral: Intel Corporation Device 1193 (rev 01)           
    00:06.1 System peripheral: Intel Corporation Device 1193 (rev 01)           
    00:07.0 System peripheral: Intel Corporation Device 1194 (rev 01)           
    00:07.1 System peripheral: Intel Corporation Device 1194 (rev 01)           
    00:07.2 System peripheral: Intel Corporation Device 1194 (rev 01)           
    00:08.0 Communication controller: Intel Corporation Device 1195 (rev 01)    
    00:08.1 Communication controller: Intel Corporation Device 1195 (rev 01)    
    00:08.2 Communication controller: Intel Corporation Device 1195 (rev 01)    
    00:08.3 Communication controller: Intel Corporation Device 1195 (rev 01)    
    00:09.0 Communication controller: Intel Corporation Device 1196 (rev 01)    
    00:09.1 Communication controller: Intel Corporation Device 1196 (rev 01)    
    00:09.2 Communication controller: Intel Corporation Device 1196 (rev 01)    
    00:0a.0 Communication controller: Intel Corporation Device 1197 (rev 01)    
    00:0b.0 Encryption controller: Intel Corporation Device 1198 (rev 01)       
    00:0c.0 System peripheral: Intel Corporation Device 1199 (rev 01)           
    00:0d.0 Multimedia audio controller: Intel Corporation Device 119a (rev 01) 
    00:0e.0 System peripheral: Intel Corporation Device 119b (rev 01)           
    00:11.0 USB controller: Intel Corporation Device 119e (rev 01)              
    00:12.0 Signal processing controller: Intel Corporation Device 119f (rev 01)
    00:13.0 Co-processor: Intel Corporation Device 11a0 (rev 01)                
    00:14.0 Co-processor: Intel Corporation Device 11a1 (rev 01)                
    00:15.0 System peripheral: Intel Corporation Device 11a2 (rev 01)           
    00:16.0 Co-processor: Intel Corporation Device 11a3 (rev 01)                
    00:16.1 Co-processor: Intel Corporation Device 11a4 (rev 01)                
    00:17.0 System peripheral: Intel Corporation Device 11a5 (rev 01)           
    00:18.0 Display controller: Intel Corporation Device 11a6 (rev 01)
    root@ubilinux:~# cat /proc/bus/pci/devices
```


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