Skip to content

vcgencmd: Make use of more restricted vcio_gencmd node if available #178

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
popcornmix wants to merge 1 commit into
base: master
Choose a base branch
from
+13 −8
Open

vcgencmd: Make use of more restricted vcio_gencmd node if available #178

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
21 changes: 13 additions & 8 deletions vcgencmd/vcgencmd.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -37,7 +37,8 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <unistd.h>
#include <sys/ioctl.h> /* ioctl */

#define DEVICE_FILE_NAME "/dev/vcio"
#define countof(x) (sizeof x/sizeof *x)

#define MAJOR_NUM 100
#define IOCTL_MBOX_PROPERTY _IOWR(MAJOR_NUM, 0, char *)

Expand All @@ -61,15 +62,19 @@ static int mbox_property(int file_desc, void *buf)
static int mbox_open()
{
int file_desc;

const char *devices[] = {"/dev/vcio_gencmd", "/dev/vcio"};
int i;
// open a char device file used for communicating with kernel mbox driver
file_desc = open(DEVICE_FILE_NAME, 0);
if (file_desc < 0) {
printf("Can't open device file: %s\n", DEVICE_FILE_NAME);
printf("Try creating a device file with: sudo mknod %s c %d 0\n", DEVICE_FILE_NAME, MAJOR_NUM);
exit(-1);
// first try the more restrictive interface but fall back to full if unavailable
for (i=0; i<countof(devices); i++)
{
file_desc = open(devices[i], 0);
if (file_desc >= 0)
return file_desc;
}
return file_desc;
printf("Can't open device file: %s\n", devices[0]);
printf("Try creating a device file with: sudo mknod %s c %d 0\n", devices[0], MAJOR_NUM);
exit(-1);
}

static void mbox_close(int file_desc) {
Expand Down