File : ip65/eth.s

 Common ethernet driver code (independant of host computer or ethernet chipset)

functions

set the destination address in the packet under construction to be the ethernet
broadcast address (FF:FF:FF:FF:FF:FF)
inputs:
 eth_outp: buffer in which outbound ethernet packet is being constructed
outputs: none

set the source address in the packet under construction to be local mac address
inputs:
 eth_outp: buffer in which outbound ethernet packet is being constructed
outputs: none

set the 'protocol' field in the packet under construction
inputs: 
   A = protocol number (per 'eth_proto_*' constants)
outputs: none

variables

constants

implementation

; Common ethernet driver code (independant of host computer or ethernet chipset)

.include "../inc/common.i"

  .export eth_set_broadcast_dest
  .export eth_set_my_mac_src
  .export eth_set_proto

  .exportzp eth_proto_ip
  .exportzp eth_proto_arp
  .exportzp eth_dest
  .exportzp eth_src
  .exportzp eth_type
  .exportzp eth_data

  .export eth_outp
  .export eth_outp_len
  .export eth_inp
  .export eth_inp_len

  .import cfg_mac

  .bss

; input and output buffers
eth_inp_len:  .res 2    ; input packet length
eth_inp:  .res 1518  ; space for input packet
eth_outp_len:  .res 2    ; output packet length
eth_outp:  .res 1518  ; space for output packet



; ethernet packet offsets
eth_dest  = 0    ; offset of destination address in ethernet packet
eth_src    = 6    ; offset of source address in ethernet packet
eth_type  = 12    ; offset of packet type in ethernet packet
eth_data  = 14    ; offset of packet data in ethernet packet

; protocols

eth_proto_ip  = 0
eth_proto_arp  = 6


  .code
;set the destination address in the packet under construction to be the ethernet
;broadcast address (FF:FF:FF:FF:FF:FF)
;inputs:
; eth_outp: buffer in which outbound ethernet packet is being constructed
;outputs: none
eth_set_broadcast_dest:
  ldx #5
  lda #$ff
:  sta eth_outp,x
  dex
  bpl :-
  rts

;set the source address in the packet under construction to be local mac address
;inputs:
; eth_outp: buffer in which outbound ethernet packet is being constructed
;outputs: none
eth_set_my_mac_src:
  ldx #5
:  lda cfg_mac,x
  sta eth_outp + 6,x
  dex
  bpl :-
  rts

;set the 'protocol' field in the packet under construction
;inputs: 
;   A = protocol number (per 'eth_proto_*' constants)
;outputs: none
eth_set_proto:
  sta eth_outp + eth_type + 1
  lda #8
  sta eth_outp + eth_type
  rts



;-- LICENSE FOR eth.s --
; The contents of this file are subject to the Mozilla Public License
; Version 1.1 (the "License"); you may not use this file except in
; compliance with the License. You may obtain a copy of the License at
; http://www.mozilla.org/MPL/
; 
; Software distributed under the License is distributed on an "AS IS"
; basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
; License for the specific language governing rights and limitations
; under the License.
; 
; The Original Code is ip65.
; 
; The Initial Developer of the Original Code is Per Olofsson,
; MagerValp@gmail.com.
; Portions created by the Initial Developer are Copyright (C) 2009
; Per Olofsson. All Rights Reserved.  
; -- LICENSE END --