Userland devfs attempt

[Bramble Whisper]

Hi all:
 I'm a newbie and trying to make a userland devfs for DFly and the
design is much more
like devctl.
 The logic is kernel provide a device named udev, in d_open the
device copyout list of devices.
 I inject the make_dev in kern_conf.c with udev_attach().
 The userland daemon udevd open and read /dev/udev and create respected node.
 The protocal is raw string like "+null @ major/minor for uid/gid with perms".
 My code can make nodes now but I have some problems:

1. Is there any block device ?
2. what is the purpose of make_sub_dev in kern_conf.c ?
3. I got /dev/ad0 for my harddisk but where is the make_dev of slice
and disklabel ?
4. I use 189 for the major of udev but what is the meaning of
"Hopefully, this list will one day be obsoleted by DEVFS" in
sys/conf/majors ?

My /dev looks better now :)
Thanks.

best wishes
whisper :)