Created
June 21, 2016 12:40
-
-
Save alex-eg/e5e051c665b67801e7322bf4cff1aede to your computer and use it in GitHub Desktop.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| #include <sys/mman.h> | |
| #include <fcntl.h> | |
| #include <stdio.h> | |
| #include <errno.h> | |
| int main(void) { | |
| off_t offset = 0; | |
| size_t size=33554432; | |
| int open_flags = O_RDWR; | |
| int prot = PROT_READ | PROT_WRITE; | |
| int fd = 0; | |
| const char reg_name[] = "/sys/bus/pci/devices/0000:01:00.0/resource1"; | |
| fd = open(reg_name, open_flags | O_CLOEXEC); | |
| if (fd != -1) { | |
| printf("Opened %s\n", reg_name); | |
| printf(" Try to map device memory (size=%lu)... ", size); | |
| void *vaddr = mmap(NULL, size, prot, MAP_SHARED, fd, offset); | |
| if (vaddr == MAP_FAILED) { | |
| perror("Error "); | |
| printf("FAILED (err=%d)\n", errno); | |
| } | |
| else { | |
| printf("Mapped at {virtualAddr=%p}... ", vaddr); | |
| munmap(vaddr, size); | |
| printf("Unmapped\n"); | |
| } | |
| close(fd); | |
| } | |
| else { | |
| printf("FAILED to open %s (err=%d)\n", reg_name, errno ); | |
| } | |
| return 0; | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment