Партнёры:
Хостинг:
devctl - device event reporting and device control interface
Also note: we specifically do not attach a device to the Vt device_t tree to avoid potential chicken and egg problems. One could argue that all of this belongs to the root node. One could also further argue that the sysctl(3) interface that we have now might more properly be an ioctl(2) interface.
SIGIO support is included in the driver. However, the author is not sure that the SIGIO support is done correctly. It was copied from a driver that had SIGIO support that likely has not been tested since Fx 3.4 or Fx 2.2.8 !
The read channel for this device is used to report changes to userland in realtime. We return one record at a time. If you try to read this device a character at a time, you will lose the rest of the data. Listening programs are expected to cope.
The sysctl and boot parameter hw.bus.devctl_disable is used to disable when no devd(8) is running.
Type Description
! A notify event, such as a link state change.
+ Device node in tree attached.
- Device node in tree detached.
? Unknown device detected.
Part Description
The nomatch messages can be used to load devices driver.
If you load a device driver, then one of two things can happen.
If the device driver attaches to something, you will get a device
attached message.
If it does not, then nothing will happen.
The attach and detach messages arrive after the event. This means one cannot use the attach message to load an alternate driver. The attach message driver has already claimed this device. One cannot use the detach messages to flush data to the device. The device is already gone.
|
Закладки на сайте Проследить за страницей |
Created 1996-2024 by Maxim Chirkov Добавить, Поддержать, Вебмастеру |