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What is PCIe endpoint?
An Endpoint is a device that resides at the bottom of the branches of the tree topology and implements a single Upstream Port toward the Root. Native PCIe Endpoints are PCIe devices designed from scratch as opposed to adding a PCIe interface to old PCI device designs.
What is bus enumeration?
Bus enumeration is the act of determining which child devices are connected to a parent device. A parent device is typically a bus adapter, but it can also be a device that supports multiple functions, such as a sound card, for which each function requires a separate set of drivers.
What is legacy endpoint in PCIe?
Legacy literally means ancestral. in other words, it means PCI-devices are being treated as an endpoint in itself and supported by pci-express fabric.
Is PCIe point-to-point?
PCIe uses a point-to-point access bus that provides outstanding data transfer speed improvement over its predecessors. In the 1980’s, early computer bus architecture was based on parallel data paths between the CPU and all components.
What is PCIe bus number?
All PCIe devices have a PCIe bus address, which is shown by lspci , listed in dmidecode (cf), and so on. On most systems, the domain is always 0000 and is omitted by lpsci and what you see is the bus, the device, and the function, which looks like this: 0a:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
What is PCI enumeration?
PCI Express Switch Enumeration Using VMM-Based DesignWare Verification IP. During the enumeration process the system software discovers all of the switch and endpoint devices that are connected to the system, determines the memory requirements and then configures the PCIe devices.
How does the enumeration of the PCIe bus happen?
PCIe enumeration is the process of detecting the devices connected to the PCIe bus. As part of PCIe enumeration, switches and endpoint devices are allocated memory from the PCIe slave address space of the HOST. – allocation and initialization of MSI/MSI-X addresses for the devices.
How is the memory allocated in PCIe enumeration?
PCIe enumeration is the process of detecting the devices connected to the PCIe bus. As part of PCIe enumeration, switches and endpoint devices are allocated memory from the PCIe slave address space of the HOST.
How big is the configuration space on PCI Express?
Bus / Device / Function (aka BDF) form hierarchy-based address (PCIe 3.0 calls this “Routing ID”) “Functions” allow multiple, logically independent agents in one physical device E.g. combination SCSI + Ethernet device 256 bytes or 4K bytes of configuration space per device