#include <stdio.h>
#include <inttypes.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

__attribute__((stdcall)) uint32_t pci_read(uint32_t bus, uint32_t dev, uint32_t fun, uint32_t offset, size_t len) {
    char path[128];
    uint32_t value = 0;
    sprintf(path, "/sys/bus/pci/devices/%4.4u:%2.2u:%2.2u.%u/config", 0, bus, dev, fun);
    int fd = open(path, O_RDONLY);
    lseek(fd, offset, SEEK_SET);
    read(fd, &value, len);
    close(fd);
    return value;
}