Matthias Ringwald writes:

hi

I found a discussion on providing /dev/.. devices by a user client on

this list from nov 2001.

Is it possible to write a pseudo device driver that can be used by

other applications over open/read/write/ioctl POSIX calls ?

I'm trying to port the lirc linux infrared control to mac os x and it

uses /dev/.. devices for their communication.

Sure. Using ioctls and devices is much more portable when you've got code that runs on other UNIXes. Note that MacOS X uses devfs (the older, uglier one, I think), so you should make the special files from inside the driver. Also note that unlike linux & solaris, MacOS & *BSD do not support factory devices. Drew PS: Here's working sample code ripped from my (real hardware) driver. The idea is to make several /dev/sample* devices, with different permissions based on device number. static int sample_macos_special_create () { int i, perms; char name[16]; sample_macos_major = cdevsw_add (-1, &sample_macos_cdevsw); if (sample_macos_major == -1) { return sample_macos_major; } /* got a cdevsw_entry, now create device nodes via devfs */ bzero (sample_macos_specials, SAMPLE_ARCH_MAX_MINOR * sizeof (void *)); for (i = 0; i < SAMPLE_ARCH_MAX_MINOR; i++) { if (i < 2 * SAMPLE_ARCH_MAX_INSTANCE) { if (i & 1) { /* priv. port, so use secure permissions */ sprintf (name, "samplep%d", i / 2); perms = 0600; } else { sprintf (name, "sample%d", i / 2); perms = 0666; } } else { sprintf (name, "sample%d", i); perms = 0666; } /* create the special file */ sample_macos_specials[i] = devfs_make_node (makedev (sample_macos_major, i), DEVFS_CHAR, UID_ROOT, GID_WHEEL, perms, name, i); if (sample_macos_specials[i] == NULL) { sample_macos_special_destroy (); return -1; } } return sample_macos_major; } /* * Undo the above. Remove the cdevsw, and free our special devices.. */ static void sample_macos_special_destroy () { int i; cdevsw_remove (sample_macos_major, &sample_macos_cdevsw); for (i = 0; i < SAMPLE_ARCH_MAX_MINOR; i++) { if (sample_macos_specials[i] != NULL) { devfs_remove (sample_macos_specials[i]); sample_macos_specials[i] = 0; } } sample_macos_major = -1; } _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.