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CM(4) | Device Drivers Manual | CM(4) |
NAME¶
cm
—
SMC Arcnet Ethernet device driver
SYNOPSIS¶
To compile this driver into the kernel, place the following lines in your kernel configuration file:device isa
device cm
if_cm_load="YES"
DESCRIPTION¶
Thecm
driver provides support for the Arcnet
ISA network adapters.
This driver also has quirks preset in the
device.hints(5) file for card detection.
HARDWARE¶
Thecm
driver supports the following card
models:
- SMC90c26
- SMC90c56
- SMC90c66 in '56 compatibility mode.
IMPLEMENTATION NOTES¶
When the NOARP flag is set on thecm
interface, it does not employ the
address resolution protocol described in arp(4)
to dynamically map between Internet and Ethernet addresses on the local
network. Instead it uses the least significant 8 bits of the IP address as the
hardware address like described in RFC 1051 and RFC 1201.
With the IFF_LINK0
flag cleared IP/ARP/RARP
encoding is done according to RFC 1201 that is, with Packet Header Definition
Standard header and packet type 212 / 213. The MTU is normally 1500. The
IFF_LINK0
flag is cleared by default.
With the IFF_LINK0
flag set, IP and ARP
encoding is done according to the deprecated RFC 1051 encoding, that is with
simple header, packet type 240 / 241, and the MTU is 507.
When switching between the two modes, use
ifconfig interfacename down
up
DIAGNOSTICS¶
The following driver specific error messages may be reported:- reset: card reset, link addr = 0x%02x (cm%d)
- The card is being reset and a new link address assigned.
- srint: restarted rx on buf cm%d
- The rx buffer has been emptied and will be reset.
SEE ALSO¶
netintro(4), watchdog(4), device.hints(5), ifconfig(8), watchdog(8)HISTORY¶
Thecm
device was ported from
NetBSD by
Max Khon ⟨fjoe@FreeBSD.org⟩ and first appeared in FreeBSD 4.6. This manual page first appeared in FreeBSD 5.3.
AUTHORS¶
This manual page was written by Tom Rhodes ⟨trhodes@FreeBSD.org⟩. The IMPLEMENTATION NOTES section was submitted byMax Khon ⟨fjoe@FreeBSD.org⟩ and originated from NetBSD.
BUGS¶
Thecm
driver code could do with a bit of
improvement, it would be nice if some one could come along and take care of
this.
The IMPLEMENTATION
NOTES section is specific to all Arcnet devices (see
sys/net/if_arcsubr.c) and should be moved
to a more generic location.July 16, 2005 | Debian |