intro —
introduction to emips special files and hardware support
This section describes the special files, related driver functions, and
  networking support available in the system. In this part of the manual, the
  SYNOPSIS section of each configurable device gives a sample specification for
  use in constructing a system description for the
  config(1) program. The
  DIAGNOSTICS section lists messages which may appear on the console and/or in
  the system error log /var/log/messages due to errors
  in device operation; see
  syslogd(8) for more
  information.
This section contains both devices which may be configured into
    the system and network related information. The networking support is
    introduced in
    netintro(4).
This section describes the hardware supported on eMIPS (Microsoft Extensible
  MIPS processor)-based platforms. Software support for these devices comes in
  two forms. A hardware device may be supported with a character or block
  device driver, or it may be used within the networking
  subsystem and have a network interface driver. Block and
  character devices are accessed through files in the file system of a special
  type; see mknod(8). Network
  interfaces are indirectly accessed through the interprocess communication
  facilities provided by the system; see
  socket(2).
A hardware device is identified to the system at configuration
    time and the appropriate device or network interface driver is then compiled
    into the system. When the resultant system is booted, the autoconfiguration
    facilities in the system probe for the device and, if found, enable the
    software support for it. If a device does not respond at autoconfiguration
    time it is not accessible at any time afterwards. To enable a device which
    did not autoconfigure, the system must be rebooted.
The autoconfiguration system is described in
    emips/autoconf(4).
    A list of the supported devices is given below.
The following systems are supported:
  - BeSquare BErkeley Emulation System-3 FPGA development board
- known as the "BEE3". This is a quad-chip FPGA system where eMIPS
      can run on each FPGA separately, on multiple FPGAs in concert, and in
      multi-processor configurations.
- Xilinx University Program board
- known as "XUP". This is the Xilinx reference board for the
      Virtex-5 series chips. It can use the same XL110T FPGA chip present on the
      BEE3.
- Xilinx ML402
- Xilinx reference board for the Virtex-4 series chip, including the
    SX35.
- Xilinx ML401
- Same as the above, but with the smaller LX25 chip.
 
The devices listed below are supported in this incarnation of the system.
  Devices are indicated by their functional interface. Not all supported devices
  are listed.
  - ace
- Xilinx SystemACE interface for Compact-FLASH cards, bears similarities to
      the IDE interface. Present on XUP and ML40x boards. Not present on
    BEE3.
- dz
- serial driver for the eMIPS console serial device. Present on all
    systems.
- enic
- Ethernet driver for the eNIC device. Present on XUP and BEE3 systems. Not
      present on ML40x systems.
- eclock
- System clock, must be configured on all systems.
- ebus
- Extensible BUS, present on all systems.
 
This eMIPS intro appeared in NetBSD
  6.0.