From a6035e0c1b5785205c73dd6510e0b83631bda75b Mon Sep 17 00:00:00 2001
From: Joshua Wise <joshua@rebirth.joshuawise.com>
Date: Mon, 26 May 2008 20:55:01 -0400
Subject: [PATCH] New ethernet code

---
 Ethernet.v   | 10 ++++---
 ethernet.asm | 75 +++++++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 75 insertions(+), 10 deletions(-)

diff --git a/Ethernet.v b/Ethernet.v
index d961585..bd3fdc7 100644
--- a/Ethernet.v
+++ b/Ethernet.v
@@ -259,16 +259,18 @@ module EnetRX(
 	reg [2:0] transition_timeout;
 	always @(posedge rxclk) if(in_data[2]^in_data[1]) transition_timeout<=0; else if(~&cnt) transition_timeout<=transition_timeout+1;
 	always @(posedge rxclk) end_of_Ethernet_frame <= &transition_timeout;
+	reg [11:0] iaddr;
 	
 	/////////////////////////////////////////////////
 	always @(posedge rxclk)
 		if (new_byte_available && !pktrdy) begin
 			odata <= data;
-			oaddr <= oaddr + 1;
+			oaddr <= iaddr;
+			iaddr <= iaddr + 1;
 			wr <= 1;
-		end else if (end_of_Ethernet_frame && (oaddr > 1)) begin
-			olength <= oaddr;
-			oaddr <= 0;
+		end else if (end_of_Ethernet_frame && (iaddr > 1)) begin
+			olength <= iaddr;
+			iaddr <= 0;
 			wr <= 0;
 			pktrdy <= 1;
 		end else if (pktclear) begin
diff --git a/ethernet.asm b/ethernet.asm
index 4bcee82..85d66e1 100644
--- a/ethernet.asm
+++ b/ethernet.asm
@@ -58,22 +58,35 @@ myGW:	db $0A, $00, $00, $01
 
 start:
 	ld sp, $D800
+	call zerobss
 	PUTSIL "Ethernet test ROM"
-.lp:	xor a			; Rest state machines
+.lp:	xor a			; Reset state machines
 	ld [ETH_STATUS], a
-	ld a, [ETH_STATUS]	; New shit?
+	ld a, [ETH_STATUS]	; Load current status
 	ld [$FF51], a
 	and $02		; New packet?
 	call nz, getpacket
 	jr .lp
 
+zerobss:
+	ld hl, bssstart
+	ld bc, bssend - bssstart
+.lp:	ld a, b
+	or c
+	ret z
+	dec bc
+	xor a
+	ld [hli], a
+	ld a, h
+	jr .lp
+
 getpacket:
 	ld a, [ETH_DATA]
 	ld b, a
 	ld a, [ETH_DATA]
 	ld c, a
 	push bc
-	ld hl, $D000
+	ld hl, packet
 .cplp:	ld a, b
 	or c
 	jr z, .done
@@ -133,15 +146,65 @@ ether_input:
 	inc hl
 	dec c
 	jr nz, .maclp
-	PUTSIL "ether_input: It's to us!"
+	; Done? Then it was to us!
+	jr .us
+.notus:	; Was it to broadcast?
 	pop hl
+	push hl
+	ld c, $06
+.bclp:	ld a, [hli]
+	cp $FF
+	jr nz, .notbc
+	dec c
+	jr nz, .bclp
+
+.us:	PUTSIL "ether_input: It's to us!"
+	; Which protocol does it belong to?
+	pop hl
+	ld b, $00
+	ld c, 12
+	add hl, bc	; Skip source and dest MAC.
+	ld a, [hli]
+	cp $08
+	jr nz, .unknownproto
+	ld a, [hli]
+	cp $06
+	jr z, .arp
+	cp $00
+	jp z, .ip
+	jr .unknownproto
+
+.notbc:	pop hl
+	PUTSIL "ether_input: Not addressed to us and not broadcast."
+	ret
 	
+.unknownproto:
+	PUTSIL "ether_input: Unknown protocol; dropping"
 	ret
-.notus:	PUTSIL "ether_input: Not to us..."
-	pop hl
+
+.arp:
+	PUTSIL "ether_input: ARP packet"
+	call arp_input
+	ret
+.ip:
+	PUTSIL "ether_input: IP packet"
+	call ip_input
 	ret
 
+arp_input:
+	ret
+
+ip_input:
+	ret
+
+	SECTION "ethdata", BSS
+bssstart	DS 0
+packet		DS 1552
+bssend		DS 0
+
+
 ; SERIAL ROUTINES ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+	SECTION "serial", HOME
 
 putc:
 	push af
-- 
2.43.0