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Access PCI Configuration Space

hard8/8

Program VGA Registers for Graphics ModesNext

Language

Compiler

2.0s Limit 256MB

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Implementation

Implement PCI configuration space access in C.

Requirements:

Implement pci_read_config(bus, device, function, offset)
Implement pci_get_vendor_device(bus, dev, func)
Implement pci_get_class_code(bus, dev, func)
Implement pci_print_device_info()
Parse and print BAR values
Show class code names
Enumerate bus 0 devices and print found devices
Handle 0xFFFF vendor ID (no device)
Show configuration address format

Test:

Show config read
Show vendor/device IDs
Show class code
Show BARs
Show enumeration results

Why This Matters

The 0xCF8/0xCFC configuration-address mechanism you implement here is exactly what the Linux kernel's drivers/pci/access.c 'type 1' config access uses on every x86 machine that hasn't switched to MMCONFIG, and enumerating all 256 buses times 32 devices times 8 functions is the same brute-force scan `lspci` performs under the hood. Misreading the bus/device/function bit-packing in the address register is a classic bug that silently probes the wrong device entirely.

Hints

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Validation Suite

main.c

Workspace 1.0

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