emailler/client/ip65/eth.s

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; 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
.import eth_outp
.import cfg_mac
; 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