pcidump.c

#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>

#include <linux/pci.h>
#include <asm/page.h>

/* A structure to declare how data is decoded */
struct pcidump_info {
    int offset; /* the data item to retrieve */
    unsigned long bitmask;
    int bool; /* true or false */
    char *string;
};

#define ONEBYTE 0xFF
#define TWOBYTES 0xFFFF
#define FOURBYTES 0xFFFFFFFF

struct pcidump_info dumpinfo[] = {
    {0,                    0,          0, "\tCompulsory registers:\n"},
    {PCI_VENDOR_ID,        TWOBYTES,   0, "Vendor id: 0x%04x\n"},
    {PCI_DEVICE_ID,        TWOBYTES,   0, "Device id: 0x%04x\n"},
    {PCI_COMMAND,          TWOBYTES,   0, "Command Register: 0x%04x\n"},
    {PCI_STATUS,           TWOBYTES,   0, "Status Register: 0x%04x\n"},
    {PCI_REVISION_ID,      ONEBYTE,    0, "Revision id (decimal): %i\n"},
    {PCI_CLASS_PROG,       ONEBYTE,    0, "Programmer Interface: 0x%02x\n"},
    {PCI_CLASS_DEVICE,     TWOBYTES,   0, "Class of device: 0x%04x\n"},
    {PCI_HEADER_TYPE,      0x7f,       0, "Header type: 0x%02x\n"},
    {PCI_HEADER_TYPE,      0x80,       1, "Multi function device: %c\n"},
    {0,                    0,          0, "\tOptional registers:\n"},
    {PCI_CACHE_LINE_SIZE,  ONEBYTE,    0, "Cache line size (decimal): %i\n"},
    {PCI_LATENCY_TIMER,    ONEBYTE,    0, "Latency timer (decimal): %i\n"},
    {PCI_BIST,             ONEBYTE,    0, "Is Built-In-Self-Test available: %c\n"},
    {PCI_BASE_ADDRESS_0,   FOURBYTES,  0, "Base Address 0 (B0): 0x%08x\n"},
    {PCI_BASE_ADDRESS_1,   FOURBYTES,  0, "Base Address 1 (B1): 0x%08x\n"},
    {PCI_BASE_ADDRESS_2,   FOURBYTES,  0, "Base Address 2 (B2): 0x%08x\n"},
    {PCI_BASE_ADDRESS_3,   FOURBYTES,  0, "Base Address 3 (B3): 0x%08x\n"},
    {PCI_BASE_ADDRESS_4,   FOURBYTES,  0, "Base Address 4 (B4): 0x%08x\n"},
    {PCI_BASE_ADDRESS_5,   FOURBYTES,  0, "Base Address 5 (B5): 0x%08x\n"},
    {PCI_SUBSYSTEM_ID,       TWOBYTES, 0, "Subsystem id: 0x%04x\n"},
    {PCI_SUBSYSTEM_VENDOR_ID, TWOBYTES,0, "Subsystem vendor: 0x%04x\n"},
    {PCI_ROM_ADDRESS,      FOURBYTES,  0, "Expantion Rom base address: 0x%08x\n"},
    {PCI_INTERRUPT_LINE,   ONEBYTE,    0, "Interrupt line (decimal): %i\n"},
    {PCI_INTERRUPT_PIN,    ONEBYTE,    0, "Interrupt pin (decimal): %i\n"},
    {PCI_MIN_GNT,          ONEBYTE,    0, "Min bus grant time (decimal): %i\n"},
    {PCI_MAX_LAT,          ONEBYTE,    0, "Max bus latency acceptable (decimal): %i\n"},
    {0x00,                 0,                       0, NULL}
};

unsigned char buffer[PAGE_SIZE];

int main(int argc, char **argv)
{
    int fd, len;
    char file[] = "/proc/bus/pci/00/00.0";
    char *fname = file;

    unsigned char *curr, *end;

    if (argc>1) {
        fname = argv[1];
    }
    if (argc != 2) {
        printf("Usage: \"%s <file name>\"\n", argv[0]);
        printf("\tfilename should embed binary pci configuration data\n");
        printf("\tif filename is missing, \"%s\" is used\n", fname);

        exit(0);
    }

    fd=open(fname, O_RDONLY);
    if (fd<0) {
        fprintf(stderr,"%s: %s: %s\n", argv[0], fname, strerror(errno));
        exit(1);
    }

    switch (len=read(fd,buffer,PAGE_SIZE)) {
      case 0:
        fprintf(stderr,"%s: %s: no data\n", argv[0], fname);
        exit(1);
      case -1:
        fprintf(stderr,"%s: %s: %s\n", argv[0], fname, strerror(errno));
        exit(1);
      default: break;
    }
    if (len < 64) {
        buffer[len]='\0';
        fprintf(stderr," %s: %s: %s\n", argv[0], fname, buffer);
        exit(1);
    }
    if (len % 64) {
        fprintf(stderr," %s: %s: incorrect data size: %i\n",
                argv[0], fname, len);
        exit(1);
    }

    for (end = buffer+len, curr = buffer; curr < end; curr += 256) {
        struct pcidump_info *ptr;
        unsigned int datum;

        for (ptr = dumpinfo; ptr->string; ptr++) {
            /*
             * Perform a little-endian read of the item
             */
            datum = curr[ptr->offset]
                | (curr[ptr->offset+1]<<8)
                    | (curr[ptr->offset+2]<<16)
                        | (curr[ptr->offset+3]<<24);
            datum &= ptr->bitmask;
            printf(ptr->string, ptr->bool ? (datum ? 'y' : 'n') : datum);
        }
        printf("\n");
    }
    return 0;
}

lspci

gcc -o pcidump pcidump.c
./pcidump /proc/bus/pci/00/12.0
 Compulsory registers:
  Vendor id: 0x1022
  Device id: 0x2000
  Command Register: 0x0003
  Status Register: 0x0280
  Revision id (decimal): 16
  Programmer Interface: 0x00
  Class of device: 0x0200
  Header type: 0x00
  Multi function device: n
 Optional registers:
  Cache line size (decimal): 0
  Latency timer (decimal): 64
  Is Built-In-Self-Test available:
  Base Address 0 (B0): 0x00001401
  Base Address 1 (B1): 0x00000000
  Base Address 2 (B2): 0x00000000
  Base Address 3 (B3): 0x00000000
  Base Address 4 (B4): 0x00000000
  Base Address 5 (B5): 0x00000000
  Subsystem id: 0x2000
  Subsystem vendor: 0x1022
  Expantion Rom base address: 0x00000000
  Interrupt line (decimal): 9
  Interrupt pin (decimal): 1
  Min bus grant time (decimal): 6
  Max bus latency acceptable (decimal): 255

Reference:
pcidump.c