diff --git a/cpu/6502/net/cs8900a.S b/cpu/6502/net/cs8900a.S new file mode 100644 index 000000000..b30612b7c --- /dev/null +++ b/cpu/6502/net/cs8900a.S @@ -0,0 +1,364 @@ +; +; Copyright (c) 2007, Adam Dunkels and Oliver Schmidt +; All rights reserved. +; +; Redistribution and use in source and binary forms, with or without +; modification, are permitted provided that the following conditions +; are met: +; 1. Redistributions of source code must retain the above copyright +; notice, this list of conditions and the following disclaimer. +; 2. Redistributions in binary form must reproduce the above copyright +; notice, this list of conditions and the following disclaimer in the +; documentation and/or other materials provided with the distribution. +; 3. Neither the name of the Institute nor the names of its contributors +; may be used to endorse or promote products derived from this software +; without specific prior written permission. +; +; THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND +; ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +; ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE +; FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +; OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +; HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +; LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +; OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +; SUCH DAMAGE. +; +; This file is part of the Contiki operating system. +; +; Author: Adam Dunkels , Oliver Schmidt +; +; $Id: cs8900a.S,v 1.1 2007/11/19 23:14:14 oliverschmidt Exp $ +; +;--------------------------------------------------------------------- + + .segment "JUMPTABLE" + + ; Driver signature + .byte $65, $74, $68 ; "eth" + .byte $01 ; Ethernet driver API version number + + ; Ethernet address +mac: .byte $00, $0E, $3A ; OUI of Cirrus Logic + .byte $11, $11, $11 + + ; Buffer attributes +bufaddr:.res 2 ; Address +bufsize:.res 2 ; Size + + ; Jump table. + .addr init + .addr poll + .addr send + .addr exit + +;--------------------------------------------------------------------- + + .zeropage + +sp: .res 2 ; Stack pointer (Do not trash !) +reg: .res 2 ; Address of rxtxreg +ptr: .res 2 ; Indirect addressing pointer +len: .res 2 ; Frame length +cnt: .res 2 ; Frame length counter + +;--------------------------------------------------------------------- + + .segment "EXTZP": zeropage + + ; Empty segment to avoid linker warnings + +;--------------------------------------------------------------------- + + .rodata + +fixup: .byte fixup02-fixup01, fixup03-fixup02, fixup04-fixup03 + .byte fixup05-fixup04, fixup06-fixup05, fixup07-fixup06 + .byte fixup08-fixup07, fixup09-fixup08, fixup10-fixup09 + .byte fixup11-fixup10, fixup12-fixup11, fixup13-fixup12 + .byte fixup14-fixup13, fixup15-fixup14, fixup16-fixup15 + .byte fixup17-fixup16, fixup18-fixup17, fixup19-fixup18 + .byte fixup20-fixup19, fixup21-fixup20, fixup22-fixup21 + .byte fixup23-fixup22, fixup24-fixup23, fixup25-fixup24 + .byte fixup26-fixup25, fixup27-fixup26, fixup28-fixup27 + .byte fixup29-fixup28, fixup30-fixup29, fixup31-fixup30 + .byte fixup32-fixup31, fixup33-fixup32, fixup34-fixup33 + .byte fixup35-fixup34, fixup36-fixup35, fixup37-fixup36 + .byte fixup38-fixup37, fixup39-fixup38, fixup40-fixup39 + .byte fixup41-fixup40, fixup42-fixup41, fixup43-fixup42 + .byte fixup44-fixup43, fixup45-fixup44, fixup46-fixup45 + +fixups = * - fixup + +;--------------------------------------------------------------------- + +rxtxreg := $FF00 ; High byte patched at runtime +txcmd := $FF04 ; High byte patched at runtime +txlen := $FF06 ; High byte patched at runtime +packetpp := $FF0A ; High byte patched at runtime +ppdata := $FF0C ; High byte patched at runtime + + .data + +;--------------------------------------------------------------------- + +init: + ; Save address of rxtxreg + sta reg + stx reg+1 + + ; Start with first fixup location + lda #<(fixup01+1) + ldx #>(fixup01+1) + sta ptr + stx ptr+1 + ldx #$FF + ldy #$00 + + ; Fixup address at location +: lda reg + eor (ptr),y ; Use XOR to support C64 RRNet + sta (ptr),y + iny + lda reg+1 + sta (ptr),y + dey + + ; Advance to next fixup location + inx + cpx #fixups + bcs :+ + lda ptr + clc + adc fixup,x + sta ptr + bcc :- + inc ptr+1 + bcs :- ; Always + + ; Turn on transmission and reception of frames + ; PACKETPP = $0112, PPDATA = $00C0 +: lda #$12 + ldx #$01 +fixup01:sta packetpp +fixup02:stx packetpp+1 + lda #$C0 + ldx #$00 +fixup03:sta ppdata +fixup04:stx ppdata+1 + + ; Accept valid unicast + broadcast frames + ; PACKETPP = $0104, PPDATA = $0D05 + lda #$04 + ldx #$01 +fixup05:sta packetpp +fixup06:stx packetpp+1 + lda #$05 + ldx #$0D +fixup07:sta ppdata +fixup08:stx ppdata+1 + + ; Set MAC address + ; PACKETPP = $0158, PPDATA = MAC[0], MAC[1] + lda #$58 + ldx #$01 +fixup09:sta packetpp +fixup10:stx packetpp+1 + lda mac + ldx mac+1 +fixup11:sta ppdata +fixup12:stx ppdata+1 + ; PACKETPP = $015A, PPDATA = MAC[2], MAC[3] + lda #$5A + ldx #$01 +fixup13:sta packetpp +fixup14:stx packetpp+1 + lda mac+2 + ldx mac+3 +fixup15:sta ppdata +fixup16:stx ppdata+1 + ; PACKETPP = 0x015C, PPDATA = MAC[4], MAC[5] + lda #$5C + ldx #$01 +fixup17:sta packetpp +fixup18:stx packetpp+1 + lda mac+4 + ldx mac+5 +fixup19:sta ppdata +fixup20:stx ppdata+1 + rts + +;--------------------------------------------------------------------- + +poll: + ; Check receiver event register to see if there + ; are any valid unicast frames avaliable + ; PACKETPP = $0124, PPDATA & $0D00 ? + lda #$24 + ldx #$01 +fixup21:sta packetpp +fixup22:stx packetpp+1 +fixup23:lda ppdata+1 + and #$0D + bne :+ + + ; No frame ready + tax + rts + + ; Process the incoming frame + ; -------------------------- + + ; Read receiver event and discard it + ; RXTXREG +: +fixup24:ldx rxtxreg+1 +fixup25:lda rxtxreg + + ; Read frame length + ; cnt = len = RXTXREG +fixup26:ldx rxtxreg+1 +fixup27:lda rxtxreg + sta len + stx len+1 + sta cnt + stx cnt+1 + + ; Adjust odd frame length + lsr + bcc :+ + inc cnt + bne :+ + inc cnt+1 + + ; Is cnt > bufsize ? +: sec + lda cnt + sbc bufsize + lda cnt+1 + sbc bufsize+1 + bcc :+ + + ; Yes, skip frame + ; PACKETPP = $0102, PPDATA = PPDATA | $0040 + lda #$02 + ldx #$01 +fixup28:sta packetpp +fixup29:stx packetpp+1 +fixup30:lda ppdata + ora #$40 +fixup31:sta ppdata + + ; No frame ready + lda #$00 + tax + rts + + ; Read bytes into buffer +: lda bufaddr + ldx bufaddr+1 + sta ptr + stx ptr+1 + ldy #$00 +read: +fixup32:lda rxtxreg + sta (ptr),y + iny +fixup33:lda rxtxreg+1 + sta (ptr),y + iny + bne :+ + inc ptr+1 +: cpy cnt + bne read + dec cnt+1 + bpl read + + ; Return frame length + lda len + ldx len+1 + rts + +;--------------------------------------------------------------------- + +send: + ; Save frame length + sta cnt + stx cnt+1 + + ; Transmit command + lda #$C0 + ldx #$00 +fixup34:sta txcmd +fixup35:stx txcmd+1 + lda cnt + ldx cnt+1 +fixup36:sta txlen +fixup37:stx txlen+1 + + ; Adjust odd frame length + lsr + bcc :+ + inc cnt + bne :+ + inc cnt+1 + + ; 8 retries +: ldy #$08 + + ; Check for avaliable buffer space + ; PACKETPP = $0138, PPDATA & $0100 ? +: lda #$38 + ldx #$01 +fixup38:sta packetpp +fixup39:stx packetpp+1 +fixup40:lda ppdata+1 + and #$01 + bne :+ + + ; No space avaliable, skip a received frame + ; PACKETPP = $0102, PPDATA = PPDATA | $0040 + lda #$02 + ldx #$01 +fixup41:sta packetpp +fixup42:stx packetpp+1 +fixup43:lda ppdata + ora #$40 +fixup44:sta ppdata + + ; And try again + dey + bne :- + rts + + ; Send the frame + ; -------------- + + ; Write bytes from buffer +: lda bufaddr + ldx bufaddr+1 + sta ptr + stx ptr+1 + ldy #$00 +write: lda (ptr),y +fixup45:sta rxtxreg + iny + lda (ptr),y +fixup46:sta rxtxreg+1 + iny + bne :+ + inc ptr+1 +: cpy cnt + bne write + dec cnt+1 + bpl write + rts + +;--------------------------------------------------------------------- + +exit: + rts + +;---------------------------------------------------------------------