; ; $VER: port.asm 1.1 (20 Aug 1995) ; ; magplip.device - Parallel Line Internet Protocol ; ; Assembler routines for efficient port handling. ; ; Original code written by Oliver Wagner and Michael Balzer. ; ; This version has been completely reworked by Marius Gröger, introducing ; slight protocol changes. The new source is a lot better organized and ; maintainable. ; ; Additional changes and code cleanup by Jan Kratochvil and Martin Mares. ; The new source is significantly faster and yet better maintainable. ; ; (C) Copyright 1993-1994 Oliver Wagner & Michael Balzer ; (C) Copyright 1995 Marius Gröger ; (C) Copyright 1995 Jan Kratochvil & Martin Mares ; All Rights Reserved ; ; $HISTORY: ; ; 20 Aug 1995 : 001.001 : + removed need for conditional compiling, as we ; we want a generic, symmetrical code ; + in interrupt handlers, A6 points already to ; SysBase ; + using JSRLIB/JMPLIB macros ; + removed implicit some assumptions on the values ; behind symbolic names ; 13 Feb 1995 : 001.000 : created (in fact manually compiled from 'C'- ; original) (jk/mm) ; section "text",code IFND HARDARE_CIA_I include "hardware/cia.i" ENDC IFND EXEC_MACROS_I include "exec/macros.i" ENDC IFND MAGPLIP_I include "magplip.i" ENDC ciaa equ $bfe001 ciab equ $bfd000 BaseA5 equ ciab+ciapra xref _CRC16 xdef _interrupt xdef _hwsend xdef _hwrecv ;---------------------------------------------------------------------------- ; ; NAME ; interrupt() - ICR FLG interrupt handler ; ; SYNOPSIS ; void interrupt(struct PLIPBase *) ; A1 ; ; FUNCTION ; This is called from the CIA resource on the receipt of an Flag- ; interrupt. This is the case if the other side starts transmission ; and writes the first byte to our port. ; We recognise this here and propagate the information to the server ; task by Signal()ing it and by setting the PLIPB_RECEIVING bit ; in the flags field. ; _interrupt: btst #PLIPB_RECEIVING,pb_Flags(a1) bne skipint move.b pb_HandshakeBit+HS_LINE(a1),d0 btst d0,ciab+ciapra beq skipint bset #PLIPB_RECEIVING,pb_Flags(a1) move.l pb_IntSigMask(a1),d0 move.l pb_Server(a1),a1 JMPLIB Signal skipint rts ;---------------------------------------------------------------------------- ; ; NAME ; hwsend() - low level send routine ; ; SYNOPSIS ; void hwsend(struct PLIPBase *) ; A0 ; ; FUNCTION ; This routine sends the PLIPBase->pb_SendFrame to the other side. It ; cares for CRC encoding, if wanted. ; _hwsend: movem.l d2-d7/a2-a3/a5-a6,-(sp) move.l a0,a2 ; a2 = PLIPBase pea FALSE ; (sp) = return value moveq #0,d3 move.l d3,d4 move.b pb_HandshakeBit+HS_REQUEST(a2),d3 ; d3 = HS_REQUEST move.b pb_HandshakeBit+HS_LINE(a2),d4 ; d4 = HS_LINE ; ; CRC wanted ? ; btst #PLIPB_SENDCRC,pb_Flags(a2) beq hww_NoCRC ; yes move.w #SYNCWORD_CRC,pb_SendFrame+pf_Sync(a2) lea pb_SendFrame+pf_data(a2),a0 move.w pb_SendFrame+pf_Size(a2),d0 subq.w #PKTFRAMESIZE_2,d0 jsr _CRC16(pc) move.w d0,pb_SendFrame+pf_CRC(a2) bra.s hww_CRC hww_NoCRC: move.w #SYNCWORD_NOCRC,pb_SendFrame+pf_Sync(a2) hww_CRC move.l pb_CIAABase(a2),a6 moveq #CIAICRF_FLG,d0 JSRLIB AbleICR ; DISABLEINT lea BaseA5,a5 st ciaa+ciaddrb-BaseA5(a5) ; SETCIAOUTPUT move.b (a5),d7 ; SAMPLEINPUT, d7 = State lea pb_SendFrame(a2),a3 move.w pb_SendFrame+pf_Size(a2),d6 addq.w #PKTFRAMESIZE_1-2,d6 move.l pb_Timeout(a2),d5 move.b (a3)+,ciaa+ciaprb-BaseA5(a5) ; WRITECIA *p++ move.l d5,d2 ; initially we wait add.l d2,d2 ; 2*Timeout move.w d2,d1 swap d2 hww_LoopShake1: move.b (a5),d0 ; ciab+ciapra eor.b d7,d0 btst d4,d0 ; WAITINPUTTOGGLE dbne d1,hww_LoopShake1 dbne d2,hww_LoopShake1 beq hww_TimedOut eor.b d0,d7 hww_MainLoop: move.b (a3)+,ciaa+ciaprb-BaseA5(a5) ; WRITECIA *p++ bchg d3,(a5) ; OUTPUTTOGGLE move.l d5,d2 move.w d2,d1 swap d2 hww_LoopShake2: move.b (a5),d0 ; ciab+ciapra eor.b d7,d0 btst d4,d0 ; WAITINPUTTOGGLE dbne d1,hww_LoopShake2 dbne d2,hww_LoopShake2 beq hww_TimedOut eor.b d0,d7 dbra d6,hww_MainLoop move.l #TRUE,(sp) ; rc = TRUE hww_TimedOut: sf ciaa+ciaddrb-BaseA5(a5) ; SETCIAINPUT bclr d3,(a5) ; CLEARREQUEST ciab+ciapra moveq #CIAICRF_FLG,d0 JSRLIB SetICR ; CLEARINT move.w #CIAICRF_FLG|CIAICRF_SETCLR,d0 JSRLIB AbleICR ; ENABLEINT move.l (sp)+,d0 ; return rc movem.l (sp)+,d2-d7/a2-a3/a5-a6 Return rts ;---------------------------------------------------------------------------- ; ; NAME ; hwrecv() - low level receive routine ; ; SYNOPSIS ; void hwrecv(struct PLIPBase *) ; A0 ; ; FUNCTION ; This routine receives a magPLIP frame and stores it into ; PLIPBase->pb_ReceiveFrame. It cares for CRC decoding, if the incoming ; packet is encoded. ; _hwrecv: movem.l d2-d7/a2-a6,-(sp) move.l a0,a2 ; a2 = PLIPBase pea FALSE ; (sp) = return value move.l pb_CIAABase(a2),a6 ; a6 = CIABase move.l pb_Timeout(a2),a4 ; a4 = Timeout moveq #0,d3 move.l d3,d5 move.b pb_HandshakeBit+HS_REQUEST(a2),d3 ; d3 = HS_REQUEST move.b pb_HandshakeBit+HS_LINE(a2),d5 ; d5 = HS_LINE lea BaseA5,a5 ; a5 = ciab+ciapra moveq #CIAICRF_FLG,d0 JSRLIB AbleICR ; DISABLEINT move.b (a5),d7 ; SAMPLEINPUT cmp.b #SYNCBYTE_HEAD,ciaa+ciaprb-BaseA5(a5) ; READCIABYTE bne hwr_TimedOut bchg d3,(a5) ; OUTPUTTOGGLE move.l a4,d2 move.w d2,d1 swap d2 hwr_LoopShake1: move.b (a5),d0 ; ciab+ciapra eor.b d7,d0 btst d5,d0 ; WAITINPUTTOGGLE dbne d1,hwr_LoopShake1 dbne d2,hwr_LoopShake1 beq hwr_TimedOut eor.b d0,d7 move.b ciaa+ciaprb-BaseA5(a5),d4 ; READCIABYTE bchg d3,(a5) ; OUTPUTTOGGLE move.b d4,d0 subq.b #SYNCBYTE_CRC,d0 subq.b #SYNCBYTE_NOCRC,d0 bcc hwr_TimedOut lea pb_ReceiveFrame+pf_Size(a2),a3 ; Read 1st length byte ; move.l a4,d2 move.w d2,d1 swap d2 hwr_LoopShake2 move.b (a5),d0 ; ciab+ciapra eor.b d7,d0 btst d5,d0 ; WAITINPUTTOGGLE dbne d1,hwr_LoopShake2 dbne d2,hwr_LoopShake2 beq hwr_TimedOut eor.b d0,d7 move.b ciaa+ciaprb-BaseA5(a5),(a3)+ ; READCIABYTE bchg d3,(a5) ; OUTPUTTOGGLE ; Read 2nd length byte ; move.l a4,d2 move.w d2,d1 swap d2 hwr_LoopShake3: move.b (a5),d0 ; ciab+ciapra eor.b d7,d0 btst d5,d0 ; WAITINPUTTOGGLE dbne d1,hwr_LoopShake3 dbne d2,hwr_LoopShake3 beq hwr_TimedOut eor.b d0,d7 move.b ciaa+ciaprb-BaseA5(a5),(a3)+ ; READCIABYTE bchg d3,(a5) ; OUTPUTTOGGLE ciab+ciapra move.w -2(a3),d6 ; = length subq.w #PKTFRAMESIZE_2,d6 bcs hwr_TimedOut cmp.w pb_MTU+2(a2),d6 bhi hwr_TimedOut addq.w #PKTFRAMESIZE_2-1,d6 ; Read main packet body ; hwr_MainLoop: move.l a4,d2 move.w d2,d1 swap d2 hwr_LoopShake4: move.b (a5),d0 ; ciab+ciapra eor.b d7,d0 btst d5,d0 dbne d1,hwr_LoopShake4 dbne d2,hwr_LoopShake4 beq hwr_TimedOut eor.b d0,d7 move.b ciaa+ciaprb-BaseA5(a5),(a3)+ ; READCIABYTE bchg d3,(a5) ; OUTPUTTOGGLE ciab+ciapra dbra d6,hwr_MainLoop hwr_DoneRead: subq.b #SYNCBYTE_CRC,d4 bne hwr_ReadOkay lea pb_ReceiveFrame+pf_data(a2),a0 move.w pb_ReceiveFrame+pf_Size(a2),d0 subq.w #PKTFRAMESIZE_2,d0 jsr _CRC16(pc) cmp.w pb_ReceiveFrame+pf_CRC(a2),d0 bne hwr_TimedOut hwr_ReadOkay: move.l #TRUE,(sp) hwr_TimedOut: bclr #PLIPB_RECEIVING,pb_Flags(a2) sf ciaa+ciaddrb-BaseA5(a5) ; SETCIAINPUT bclr d3,(a5) ; CLEARREQUEST ciab+ciapra moveq #CIAICRF_FLG,d0 JSRLIB SetICR ; CLEARINT move.w #CIAICRF_FLG|CIAICRF_SETCLR,d0 JSRLIB AbleICR ; ENABLEINT move.l (sp)+,d0 ; return value movem.l (sp)+,d2-d7/a2-a6 rts end