| Offset | Field | Purpose | |--------|-------|---------| | 0x00 | Vendor ID | Manufacturer (e.g., 0x10DE for NVIDIA) | | 0x02 | Device ID | Specific model (e.g., 0x1B80 for GTX 1080) | | 0x08 | Class Code | Device category (e.g., 0x030000 for VGA) | | 0x10 | BARs (Base Address Registers) | Memory/I/O addresses assigned by firmware | | 0x3C | Interrupt Line | Which IRQ the device is wired to | The driver matches the Vendor/Device ID against its internal table. A mismatch means the driver should ignore the device. 3. Key Responsibilities of a PCI Driver A. Probing – The Handshake The kernel calls the driver’s probe() function when a matching device is found. Inside probe() , the driver must:
// 6. Initialize device-specific state my_device_init(regs); pci device driver
But hardware alone is inert. The true intelligence lies in the —the software layer that translates the operating system's generic requests into specific commands the hardware understands. | Offset | Field | Purpose | |--------|-------|---------|
// 5. Set up interrupt handler request_irq(pdev->irq, my_interrupt_handler, IRQF_SHARED, "my_driver", dev); Key Responsibilities of a PCI Driver A
static int my_probe(struct pci_dev *pdev, const struct pci_device_id *id)