osd-contiki/cpu/6502/net/lan91c96.S

416 lines
9.6 KiB
ArmAsm

;
; Copyright (c) 2003-2007, Adam Dunkels, Josef Soucek 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 <adam@sics.se>, Josef Soucek <josef.soucek@ide64.org>,
; Oliver Schmidt <ol.sc@web.de>
;
;---------------------------------------------------------------------
.segment "JUMPTABLE"
; Driver signature
.byte $65, $74, $68 ; "eth"
.byte $01 ; Ethernet driver API version number
; Ethernet address
mac: .byte $00, $80, $0F ; OUI of Standard Microsystems
.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 register base
ptr: .res 2 ; Indirect addressing pointer
len: .res 2 ; Frame length
;---------------------------------------------------------------------
.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
fixups = * - fixup
;---------------------------------------------------------------------
ethbsr := $FF0E ; Bank select register R/W (2B)
; Register bank 0
ethtcr := $FF00 ; Transmition control register R/W (2B)
ethephsr := $FF02 ; EPH status register R/O (2B)
ethrcr := $FF04 ; Receive control register R/W (2B)
ethecr := $FF06 ; Counter register R/O (2B)
ethmir := $FF08 ; Memory information register R/O (2B)
ethmcr := $FF0A ; Memory Config. reg. +0 R/W +1 R/O (2B)
; Register bank 1
ethcr := $FF00 ; Configuration register R/W (2B)
ethbar := $FF02 ; Base address register R/W (2B)
ethiar := $FF04 ; Individual address register R/W (6B)
ethgpr := $FF0A ; General address register R/W (2B)
ethctr := $FF0C ; Control register R/W (2B)
; Register bank 2
ethmmucr := $FF00 ; MMU command register W/O (1B)
ethautotx := $FF01 ; AUTO TX start register R/W (1B)
ethpnr := $FF02 ; Packet number register R/W (1B)
etharr := $FF03 ; Allocation result register R/O (1B)
ethfifo := $FF04 ; FIFO ports register R/O (2B)
ethptr := $FF06 ; Pointer register R/W (2B)
ethdata := $FF08 ; Data register R/W (4B)
ethist := $FF0C ; Interrupt status register R/O (1B)
ethack := $FF0C ; Interrupt acknowledge register W/O (1B)
ethmsk := $FF0D ; Interrupt mask register R/W (1B)
; Register bank 3
ethmt := $FF00 ; Multicast table R/W (8B)
ethmgmt := $FF08 ; Management interface R/W (2B)
ethrev := $FF0A ; Revision register R/W (2B)
ethercv := $FF0C ; Early RCV register R/W (2B)
.data
;---------------------------------------------------------------------
init:
; Save address of register base
sta reg
stx reg+1
; Start with first fixup location
lda #<(fixup01+1)
ldx #>(fixup01+1)
sta ptr
stx ptr+1
ldx #$FF
ldy #$00
; Fixup address at location
: lda reg
ora (ptr),y
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
; Reset ETH card
: lda #$00 ; Bank 0
fixup00:sta ethbsr
lda #%10000000 ; Software reset
fixup01:sta ethrcr+1
ldy #$00
fixup02:sty ethrcr
fixup03:sty ethrcr+1
; Delay
: cmp ($FF,x) ; 6 cycles
cmp ($FF,x) ; 6 cycles
iny ; 2 cycles
bne :- ; 3 cycles
; 17 * 256 = 4352 -> 4,4 ms
; Enable transmit and receive
lda #%10000001 ; Enable transmit TXENA, PAD_EN
ldx #%00000011 ; Enable receive, strip CRC ???
fixup04:sta ethtcr
fixup05:stx ethrcr+1
lda #$01 ; Bank 1
fixup06:sta ethbsr
fixup07:lda ethcr+1
ora #%00010000 ; No wait (IOCHRDY)
fixup08:sta ethcr+1
lda #%00001001 ; Auto release
fixup09:sta ethctr+1
; Set MAC address
lda mac
ldx mac+1
fixup10:sta ethiar
fixup11:stx ethiar+1
lda mac+2
ldx mac+3
fixup12:sta ethiar+2
fixup13:stx ethiar+3
lda mac+4
ldx mac+5
fixup14:sta ethiar+4
fixup15:stx ethiar+5
; Set interrupt mask
lda #$02 ; Bank 2
fixup16:sta ethbsr
lda #%00000000 ; No interrupts
fixup17:sta ethmsk
rts
;---------------------------------------------------------------------
poll:
fixup18:lda ethist
and #%00000001 ; RCV INT
bne :+
; No packet available
tax
rts
; Process the incoming packet
; ---------------------------
: lda #$00
ldx #%11100000 ; RCV, AUTO INCR., READ
fixup19:sta ethptr
fixup20:stx ethptr+1
; Last word contains 'last data byte' and $60 or 'fill byte' and $40
fixup21:lda ethdata ; Status word
fixup22:lda ethdata ; Need high byte only
; Move ODDFRM bit into carry:
; - Even packet length -> carry clear -> subtract 6 bytes
; - Odd packet length -> carry set -> subtract 5 bytes
lsr
lsr
lsr
lsr
lsr
; The packet contains 3 extra words
fixup23:lda ethdata ; Total number of bytes
sbc #$05 ; Actually 5 or 6 depending on carry
sta len
fixup24:lda ethdata
sbc #$00
sta len+1
; Is bufsize < len ?
sec
lda bufsize
sbc len
lda bufsize+1
sbc len+1
bcs :+
; Yes, skip packet
; Remove and release RX packet from the FIFO
lda #%10000000
fixup25:sta ethmmucr
; No packet available
lda #$00
tax
rts
; Read bytes into buffer
: lda bufaddr
ldx bufaddr+1
sta ptr
stx ptr+1
ldx len+1
ldy #$00
read:
fixup26:lda ethdata
sta (ptr),y
iny
bne :+
inc ptr+1
: cpy len
bne read
dex
bpl read
; Remove and release RX packet from the FIFO
lda #%10000000
fixup27:sta ethmmucr
; Return packet length
lda len
ldx len+1
rts
;---------------------------------------------------------------------
send:
; Save packet length
sta len
stx len+1
; Allocate memory for TX
txa
ora #%00100000
fixup28:sta ethmmucr
; 8 retries
ldy #$08
; Wait for allocation ready
:
fixup29:lda ethist
and #%00001000 ; ALLOC INT
bne :+
; Shouldn't we do something here to actively free memory,
; maybe removing and releasing an RX packet from the FIFO ???
; And try again
dey
bne :-
rts
; Acknowledge interrupt, is it necessary ???
: lda #%00001000
fixup30:sta ethack
; Set packet address
fixup31:lda etharr
fixup32:sta ethpnr
lda #$00
ldx #%01000000 ; AUTO INCR.
fixup33:sta ethptr
fixup34:stx ethptr+1
; Status written by CSMA
lda #$00
fixup35:sta ethdata
fixup36:sta ethdata
; Check packet length parity:
; - Even packet length -> carry set -> add 6 bytes
; - Odd packet length -> carry clear -> add 5 bytes
lda len
eor #$01
lsr
; The packet contains 3 extra words
lda len
adc #$05 ; Actually 5 or 6 depending on carry
fixup37:sta ethdata
lda len+1
adc #$00
fixup38:sta ethdata
; Send the packet
; ---------------
; Write bytes from buffer
lda bufaddr
ldx bufaddr+1
sta ptr
stx ptr+1
ldx len+1
ldy #$00
write: lda (ptr),y
fixup39:sta ethdata
iny
bne :+
inc ptr+1
: cpy len
bne write
dex
bpl write
; Odd packet length ?
lda len
lsr
bcc :+
; Yes
lda #%00100000 ; ODD
bne :++ ; Always
; No
: lda #$00
fixup40:sta ethdata ; Fill byte
:
fixup41:sta ethdata ; Control byte
; Add packet to FIFO
lda #%11000000 ; ENQUEUE PACKET - transmit packet
fixup42:sta ethmmucr
rts
;---------------------------------------------------------------------
exit:
rts
;---------------------------------------------------------------------