Provides access to Ethernet high-performance LAN adapters by way of the Ethernet device handler.
The /dev/entn character special file provides access to the Ethernet device handler for the purpose of providing access to an Ethernet LAN. The device handler supports up to four adapters, each of which may be running either or both of the standard Ethernet and IEEE 802.3 protocols.
When accessing the Ethernet device handler, the following should be taken into account:
The device handler can be loaded and unloaded. The handler supports the configuration calls to initialize and terminate itself.
Calls other than the open and close subroutines are discussed based on the mode in which the device handler is operating.
The Ethernet device handler supports the open and close, read, write, and ioctl subroutines in the following manner:
The device handler supports the
/dev/entn special file as a character-multiplex special
file. The special file must be opened for both reading and writing (O_RDWR). However, there are no particular
considerations for closing the special file. The special file name used
in an open call depends upon how the device is to be opened.
Types of special file names are:
Can take the form of a read, readx, readv, or readvx subroutine. For this call, the device handler copies the data into the buffer specified by the caller.
Can take the form of a write, writex, writev, or writevx subroutine. For this call, the device handler copies the user data into a buffer and transmits the data on the LAN.
The Ethernet device handler
supports the following ioctl operations:
| CCC_GET_VPD | Returns adapter vital product data (VPD) if available and valid. |
| CIO_GET_FASTWRT | Returns the parameters required to issue an ent_fastwrt call. |
| CIO_GET_STAT | Returns current adapter and device handler status. |
| CIO_HALT | Halts a session and unregisters a network ID. |
| CIO_QUERY | Returns the current RAS counter values, as defined in the sys/comio.h and sys/entuser.h files. |
| CIO_START | Starts a session and registers a network ID. |
| ENT_SET_MULTI | Sets or clears a multicast address. |
| IOCINFO | Returns a device information structure to the user specified area. The devtype field value is DD_NET_DH and the devsubtype field is value DD_EN, as defined in the sys/devinfo.h file. |
The following error codes may be
returned when accessing the device handler through the
dev/entn special file:
This file functions with the Ethernet device handler.
The entn special file is part of Base Operating System (BOS) Runtime.
The close subroutine, open subroutine, read or readx subroutine, write or writex subroutine, ioctl subroutine.