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     cs — Ethernet device driver


     To compile this driver into the kernel, place the following line in your kernel
     configuration file:

           device cs

     Alternatively, to load the driver as a module at boot time, place the following line in


     In /boot/device.hints:"isa"


     The cs driver is not present in FreeBSD 13.0 and later.  See for more information.


     The cs driver provides support for ISA Ethernet adapters based on the Crystal Semiconductor
     CS8900 and CS8920 NICs.  These devices are used on the IBM EtherJet ISA adapters and in many
     embedded applications where the high integration, small size and low cost of the CS89x0
     family compensate for their drawbacks.

     The cs driver will obtain configuration parameters either from /boot/device.hints or from
     the card.  At least the I/O port number must be specified.  Other parameters specified in
     /boot/device.hints will be used if present; the card may be soft-configured so these may be
     any valid value.  Adapters based on the CS8920 normally offer PnP configuration and the
     driver will detect the IBM EtherJet and the CSC6040 adapters automatically.

     Note that the CS8900 is limited to 4 IRQ values; these are normally implemented as 5, 10, 11
     and 12.  The CS8920 has no such limitation.

     Memory-mapped and DMA operation are not supported at this time.

     In addition to the ISA devices, the PC Card devices based on the CS889x0 family are also
     supported.  The IBM EtherJet PCMCIA Card is the only known device based on this chip.  The
     PC Card support does not need the above specific ISA hints to work.  The PC Card support may
     not work for 10base2 (thinnet) connections and may bogusly claim to support 10base5 (there
     are no known cards that have an AUI necessary for 10base5 support on their dongles).


     cs%d: full/half duplex negotiation timeout  The attempt to negotiate duplex settings with
     the hub timed out.  This may indicate a cabling problem or a faulty or incompatible hub.

     cs%d: failed to enable <media>  The CS89x0 failed to select the nominated media, either
     because it is not present or not operating correctly.

     cs%d: No EEPROM, assuming defaults  The CS89x0 does not have an EEPROM, or the EEPROM is
     hopelessly damaged.  Operation will only be successful if the configuration entry lists
     suitable values for the adapter.

     cs%d: Invalid irq  The IRQ specified in the configuration entry is not valid for the

     cs%d: Could not allocate memory for NIC  There is a critical memory shortage.  The adapter
     will not function.

     cs%d: Adapter has no media  The adapter is not configured for a specific media type.  The
     media type will have to be manually set.

     This is a %s, but LDN %d is disabled  The PnP probe code found a recognised adapter, but the
     adapter is disabled.

     failed to read pnp parms  A PnP adapter was found, but configuration parameters for it could
     not be read.

     failed to pnp card parameters  The parameters obtained via PnP were not accepted by the
     driver.  The adapter may not function.


     arp(4), netintro(4), ng_ether(4), ifconfig(8)


     The cs device driver was written by Maxim Bolotin and Oleg Sharoiko.  This manpage was
     written by Michael Smith.


     The CS89x0 family of adapters have a very small RAM buffer (4K).  This may cause problems
     with extremely high network loads or bursty network traffic.  In particular, NFS operations
     should be limited to 1k read/write transactions in order to avoid overruns.