Crate pcics

source ·
Expand description

§PCI configuration space

PCI configuration space is the underlying way that the Conventional PCI, PCI-X and PCI Express perform auto configuration of the cards inserted into their bus.

This library implements decoding PCI configuration space and PCI Express extended configuration space.

§Design

The main purpose of this library is to represent configuration space data as a hierarchical structures. Therefore, CPU and memory usage may not be optimal.

The library is divided into three parts:

§Usage

let conf_space_data = include_bytes!(concat!(
    env!("CARGO_MANIFEST_DIR"),
    "/tests/data/device/8086_2030/config"
));

let header = Header::try_from(&conf_space_data[..DDR_OFFSET]).unwrap();
assert_eq!((0x8086, 0x2030), (header.vendor_id, header.device_id));

let mut caps = Capabilities::new(&conf_space_data[DDR_OFFSET..ECS_OFFSET], &header);
let BridgeSubsystemVendorId {
    subsystem_vendor_id,
    ..
} = caps
    .find_map(|cap| {
        if let Ok(Capability {
            kind: CapabilityKind::BridgeSubsystemVendorId(ssvid),
            ..
        }) = cap
        {
            Some(ssvid)
        } else {
            None
        }
    })
    .unwrap();
assert_eq!(0x8086, subsystem_vendor_id);

let mut ecaps = ExtendedCapabilities::new(&conf_space_data[ECS_OFFSET..]);
let VendorSpecificExtendedCapability { header, .. } = ecaps
    .find_map(|ecap| {
        if let Ok(ExtendedCapability {
            kind: ExtendedCapabilityKind::VendorSpecificExtendedCapability(vsec),
            ..
        }) = ecap
        {
            Some(vsec)
        } else {
            None
        }
    })
    .unwrap();
assert_eq!(0x0c, header.vsec_length);

More detailed usage in modules descriptions

Re-exports§

Modules§

Constants§

  • DDR_LENGTH
    Device dependent region length
  • DDR_OFFSET
    Device dependent region starts at 0x40 offset
  • ECS_LENGTH
    Extended configuration space length
  • ECS_OFFSET
    Extended configuration space starts at 0x100 offset