【Linux c】读写pcie配置空间（安装lib库）

readme.txt + pcie.c + in.txt +Makefile 

可参考源码是： lspci

readme.txt

Please open the terminal in your linux system, then:

1.Please install two lib about pcie:

apt-get install libpciaccess-dev
apt-get install pciutils-dev

2.Please find the road path of libpci.a in your system, follows the commands:

cd /usr
find ./ -name "*pci*"

then, please modify the road path of the Makefile.

(in my ubuntu, it's road path: /usr/lib/i386-linux-gnu/libpci.a )

3.Please go into the directory of pcie.c, follows the commands:

make
./pcie

4. If you want to write pcie's configuration space, please write your data into the in.txt file.
Separating each byte with space .Such as "3a 4b 5c 6d 7e".

5. You computer may be poweroff, when you modify the byte 37, 38, 39 of PCIE configuration space. (that is,if you modify the Base Address Register 6)

pcie.c

#include <stdio.h>#include <ctype.h>#include <string.h>#include "/usr/include/pci/pci.h"#include "/usr/include/pciaccess.h"int config_space_read(int vendor_id, int device_id, int print){int i = 0;int ret = 0;struct pci_access * myaccess;struct pci_dev * mydev;myaccess = pci_alloc();pci_init(myaccess);pci_scan_bus(myaccess);for (mydev = myaccess->devices; mydev; mydev = mydev->next){pci_fill_info(mydev, PCI_FILL_IDENT | PCI_FILL_BASES | PCI_FILL_CLASS);if(mydev->vendor_id == vendor_id && mydev->device_id == device_id){if (print == 1){printf("Configuration space content:\n");for (i = 0; i < 64; i++) {ret = pci_read_byte(mydev, i);printf("%d: %02x \t", i, ret);if(i%4 == 3 ){printf("\n");}}}else{for (i = 0; i < 64; i++) {pci_read_byte(mydev, i);    }}return 1;}}pci_free_dev(mydev);    pci_cleanup(myaccess);    return 0;}int config_space_write(int vendor_id, int device_id,  int position, unsigned int data[],int length){int i = 0;struct pci_access * myaccess;struct pci_dev * mydev;int flag;myaccess = pci_alloc();pci_init(myaccess);pci_scan_bus(myaccess);for (mydev = myaccess->devices; mydev; mydev = mydev->next){pci_fill_info(mydev, PCI_FILL_IDENT | PCI_FILL_BASES | PCI_FILL_CLASS);if(mydev->vendor_id == vendor_id && mydev->device_id == device_id){for(i = 0; i < length; i++, position++){pci_write_byte(mydev, position, data[i]);}return 1;}}pci_free_dev(mydev);    pci_cleanup(myaccess);return 0;}void main(void){int vendor_id ;int device_id ;int choose ;int num ;int length ;unsigned int data[256] = {0};int position = 0;int i = 0 ;int flag = 1;FILE *fp;int print = 0;printf("Please input vid & pid(for example:8086 1c02):");scanf("%x%x", &vendor_id, &device_id);printf("\t\t 1-Configuration space read test\t\t 2-Configuration space write test \n please choose:");scanf("%d", &choose);switch(choose){case 1:{printf("Enter the number of times :");scanf("%d", &num);print = 1;config_space_read(vendor_id, device_id, print);print = 0;for(i = 1; i < num; i++){config_space_read(vendor_id, device_id, print);}printf("Read PCIE configuration space %d times\n", num);break;}case 2:{printf("Enter the number of times:");scanf("%d", &num);printf("Enter the starting position (decimal):");scanf("%d", &position);printf("Enter the length:");scanf("%d", &length);fp = fopen("in.txt", "r");if (fp == NULL){printf("Can't open file!\n");return ;}for(i = 0; i< length; i++){fscanf(fp, "%x", &data[i]);}printf("The data is :\n");for(i = 0; i< length; i++){printf("%x \t", data[i]);if (i%4 == 3){printf("\n");}}printf("\n");fclose(fp);for(i = 0; i < num; i++){flag = config_space_write(vendor_id, device_id, position, data, length);if(flag == 0){printf("This device not exist!\n");}}printf("Write PCIE configuration space %d times\n", num);print = 1;config_space_read(vendor_id, device_id, print);break;}}return ;}

in.txt

ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 

 
Makefile

pcie:pcie.c
gcc -Wall -o pcie pcie.c /usr/lib/i386-linux-gnu/libpci.a -lz
clean:
rm -fr *.o *~