<<On Tue, 29 Feb 2000 18:59:50 +0100 (CET), Luigi Rizzo <[EMAIL PROTECTED]> said:

> can you clarify this ? Looong ago i used the '586 on a bridge and it did let
> me write the MAC header...

The 82586 has a mode bit which selects one of two possibilities:

1) The transmit command specifies the destination address and
length/ethertype field; the source address is inserted by hardware.
The receive buffer descriptor gets the source address and
length/ethertype.

2) The transmit and receive buffers include a full Ethernet header.

I can't say off the top of my head which the `ie' driver uses, but I
would bet on (2) because that's easier for the driver to deal with.

These sorts of controllers are the reason why ether_input takes the
Ethernet header as a separate parameter.

-GAWollman

--
Garrett A. Wollman   | O Siem / We are all family / O Siem / We're all the same
[EMAIL PROTECTED]  | O Siem / The fires of freedom 
Opinions not those of| Dance in the burning flame
MIT, LCS, CRS, or NSA|                     - Susan Aglukark and Chad Irschick


To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-current" in the body of the message

Reply via email to