Chip 1994 February

home *** CD-ROM | disk | FTP | other *** search

/ Chip 1994 February / CHIP0294.ISO / digital / magazin / trumpet / pktdrvs / davidsys.asm < prev next >

Wrap

Assembly Source File | 1993-06-10 | 46.5 KB | 1,657 lines

page 58, 132 ;DBGINT3 equ 0 ;DEBUG equ 1 ; FOR NOW version equ 5 ; version of this file s8005_version equ 1 ; SEEQ 8005 stuff (not separate (yet)) ;version ; 1 = initially from Mark Dye ; 2 = Fix spin loop bug (cx=0 ->65536), broke on slower systems (6MHz) ; 3 = Fix '-n' bug, fix warnings ; 4 = Fix Compaq DOS bug (we must do STI after set_recv_isr) ; Also, compile with DBGINT3 commmented out. ; I thought that 0=false, 1=true, but they were IFDEFfed! ; Also, Fix section to ignore broadcasts that we initiated ; 5 = Release version (nothing changed) ;s8005_version ; 0 = Initially from MD ; 1 = Fix 8-bit insb bug (broke on 8088 PCs) ; Copyright 1991 DAVID Systems, Inc (Sunnyvale, CA) and Marc S Dye ; (d.b.a. ayuda Company - Camarillo, CA). Distribution of this code ; including any derivation thereof, shall be made so as to afford the ; recipient of such distribution a copy of this source code, including ; any alterations, at no charge (except for copying, media, and shipping ; costs). Any distribution of this source or derivations must contain ; this copyright notice. Documentation describing this work or its ; derivations must acknowledge the copyright holders herein. The names ; of the copyright holders may not be used to advertise, signify, or ; otherwise characterize any derived work, except for the aforementioned ; copyright acknowledgement. This work is provided AS IS, with NO ; WARRANTIES expressed or implied, NOR any representations made as to ; its suitability or fitness for any purpose whatsoever. The recipient ; assumes full responsibility for use of this work. ; Some patches made by: ; Jeff Douglass ifdef DEBUG private macro SYM public SYM endm else private macro SYM endm endif include defs.asm ; Ethernet-2 header length defined ;# ENET_HDR equ 2*EADDR_LEN + 4 ;was +2 ; assemble a select few instructions (16-bit i/o) from the extended set ; otherwise, must do only 8086-compatible stuff! .286p ; Definitions of interface to the SEEQ 8005 EDLC. See the SEEQ data book ; for complete details of this device. ; 8005 directly-addressable register offsets (from i/o base address) COMSTAT_R equ 0 ; COMMAND / STATUS CONFIG1_R equ 2 ; CONFIGURATION 1 CONFIG2_R equ 4 ; CONFIGURATION 2 REA_PTR_R equ 6 ; Receive End Area Pointer BUFWIN_R equ 8 ; Buffer Window RX_PTR_R equ 10 ; Receive Pointer TX_PTR_R equ 12 ; Transmit Pointer DMA_ADDR_R equ 14 ; DMA Address ; 8005 COMMAND register DMA_INT_EN equ 0001h RX_INT_EN equ 0002h TX_INT_EN equ 0004h WINDOW_INT_EN equ 0008h DMA_INT_ACK equ 0010h RX_INT_ACK equ 0020h TX_INT_ACK equ 0040h WINDOW_INT_ACK equ 0080h SET_DMA_ON equ 0100h SET_RX_ON equ 0200h SET_TX_ON equ 0400h SET_DMA_OFF equ 0800h SET_RX_OFF equ 1000h SET_TX_OFF equ 2000h FIFO_READ equ 4000h FIFO_WRITE equ 8000h ; 8005 STATUS register DMA_INT equ 0010h RX_INT equ 0020h TX_INT equ 0040h WINDOW_INT equ 0080h DMA_ON equ 0100h RX_ON equ 0200h TX_ON equ 0400h FIFO_FULL equ 2000h FIFO_EMPTY equ 4000h FIFO_DIR equ 8000h ; 8005 CONFIGURATION 1 register MATCH_BITS_M equ 0C000h MATCH_ONLY equ 0000h MATCH_BROAD equ 4000h MATCH_MULTI equ 8000h MATCH_ALL equ 0C000h ALL_STATIONS equ 3F00h STATION_0_EN equ 0100h STATION_1_EN equ 0200h STATION_2_EN equ 0400h STATION_3_EN equ 0800h STATION_4_EN equ 1000h STATION_5_EN equ 2000h DMA_LENGTH_M equ 00C0h NBYTES_1 equ 0000h NBYTES_2 equ 0040h NBYTES_4 equ 0080h NBYTES_8 equ 00C0h DMA_INTERVAL_M equ 0030h CONTINUOUS equ 0000h DELAY_800 equ 0010h DELAY_1600 equ 0020h DELAY_3200 equ 0030h BUFFER_CODE_M equ 000Fh STATION_0_SEL equ 0000h STATION_1_SEL equ 0001h STATION_2_SEL equ 0002h STATION_3_SEL equ 0003h STATION_4_SEL equ 0004h STATION_5_SEL equ 0005h PROM_SEL equ 0006h TEA_SEL equ 0007h BUFFER_MEM_SEL equ 0008h INT_VECTOR_SEL equ 0009h ; Ether-T PC/AT device configuration register -- access is overloaded onto ; the set of registers accessible via the reserved range in CONFIGURATION 1 CARD_CONFIG_SEL equ 000Fh SET_16BITMODE_M equ 0080h ; OR mask for 16 bit mode ; 8005 CONFIGURATION 2 register BYTE_SWAP equ 0001h AUTO_UPDATE_REA equ 0002h CRC_ERR_EN equ 0008h DRIBBLE_EN equ 0010h SHORT_FRAME_EN equ 0020h SLOT_TIME_SEL equ 0040h XMIT_NO_PREAM equ 0080h ADDR_LENGTH equ 0100h RECEIVE_CRC equ 0200h XMIT_NO_CRC equ 0400h LOOPBACK_EN equ 0800h KILL_WATCHDOG equ 1000h RESET equ 8000h ; 8005 TRANSMIT HEADER COMMAND BYTE (byte 3 of transmit packet header) BABBLE_INT_EN equ 01h COLL_INT_EN equ 02h COLL_16_INT_EN equ 04h XMIT_OK_INT_EN equ 08h DATA_FOLLOWS equ 20h ; also in RECEIVE HEADER COMMAND BYTE CHAIN_CONTINUE equ 40h ; also in RECEIVE HEADER COMMAND BYTE PACKET_PRESENT equ 80h TX_HEADER_Z equ 4 ; # of bytes in a TX header ; 8005 TRANSMIT HEADER STATUS BYTE (byte 4 of transmit packet header) BABBLE_ERR equ 01h COLL equ 02h COLL_16_ERR equ 04h HDR_DONE equ 80h ; 8005 RECEIVE HEADER COMMAND BYTE (byte 3 of receive packet header) ;DATA_FOLLOWS 20h from TRANSMIT HEADER COMMAND BYTE ;CHAIN_CONTINUE 40h from TRANSMIT HEADER COMMAND BYTE ; 8005 RECEIVE HEADER STATUS BYTE (byte 4 of receive packet header) OVERSIZE equ 01h CRC_ERR equ 02h DRIBBLE_ERR equ 04h SHORT_FRAME equ 08h ; 8005 Receive Area Base Pointer RCV_PTR equ ((4 + GIANT + 4 + 255) AND NOT 0FFh) ; 8005 Transmit End Area Pointer (upper 8-bits) TEA_INIT equ (((RCV_PTR - 1) / 256) AND 0FFh) ; macro to provide a delay after dinking w/ 8005 registers io_delay macro CNTVAR local io_delay_loop, skip_delay push cx mov cx, CNTVAR jcxz skip_delay io_delay_loop: nop loop io_delay_loop skip_delay: pop cx endm ; macros to get and set the various device registers ; these assume that a proper 'loadport' context exists, that input/output ; register values are in AX (for word i/o) or AL (for byte i/o) get_r macro R setport R call inb_8005 endm getw_r macro R setport R call [inw_fn] endm set_r macro R setport R call outb_8005 endm setw_r macro R setport R call [outw_fn] endm ; wait for the 8005 FIFO to be free fifo_wait macro local fifo_wait_loop setport COMSTAT_R ; fix access within the loop fifo_wait_loop: getw_r COMSTAT_R ; wait for the FIFO to be free to use and ax, FIFO_EMPTY+FIFO_DIR cmp ax, FIFO_EMPTY jne fifo_wait_loop ; loop endm CODE segment byte public assume cs:CODE, ds:CODE public INT_NO, IO_ADDR INT_NO db 3, 0, 0, 0 ; interrupt number IO_ADDR dw 300h, 0 ; (factory) i/o port address public DRIVER_CLASS, DRIVER_TYPE, DRIVER_NAME, DRIVER_FUNCTION public PARAMETER_LIST, INT_NUM DRIVER_CLASS db BLUEBOOK, IEEE8023, 0 DRIVER_TYPE db 70 ; Ether-T PC/AT, specifically DRIVER_NAME db "Ether-T PC/AT", 0 ; name of the driver DRIVER_FUNCTION db 2 ; standard plus extensions (except ; specific multicast) PARAMETER_LIST label byte db 1 ; major rev of packet driver spec db 9 ; minor rev of packet driver spec db 14 ; length of parameter list db EADDR_LEN ; length of MAC-layer address dw GIANT ; MTU, including headers dw MAX_MULTICAST * EADDR_LEN ; buffer size of multicast addresses dw 0 ; (# of back-to-back MTU recvs) - 1 dw 0 ; (# of successive xmits) - 1 INT_NUM dw 0 ; interrupt # to hook for post-EOI ; processing, 0 == none public RCV_MODES ; Receive mode set-up dispatch table. Refers to actual code frags below that ; do the job. RCV_MODES dw 7 ; number of receive modes in our table dw 0 ; none exists dw rcv_mode_1 ; receiver off dw rcv_mode_2 ; only packets for this station dw rcv_mode_3 ; mode 2 plus broadcast dw 0 ; mode 3 plus limited multicast dw rcv_mode_5 ; mode 3 plus all multicast dw rcv_mode_6 ; all packets ; per-device instance structures -- keep state of the device -- ones marked ; as (copy) are soft copies of things actually on the device private command_r command_r dw 0 ; COMMAND (copy, sort of) private config1_r_copy config1_r_copy dw 0 ; CONFIGURATION 1 (copy) private config2_r_copy config2_r_copy dw 0 ; CONFIGURATION 2 (copy) private cardconfig_r cardconfig_r db 0 ; CARD CONFIGURATION (copy) private rcv_errors rcv_errors db 0 ; want to receive even flawed packets private rcv_ptr_copy rcv_ptr_copy dw 0 ; current (next) received packet ptr private transmit transmit db 0 ; currently transmitting db ? station_0 db 6 dup(0) ;current address (for disallowing ; broadcast packets)(JLD)(9-25-91) ; i/o instruction processing variables private delay_mult delay_mult dw 10, 0 ; delay multiplier / divisor - is ; a tens fraction: delay becomes ; (calibrated_delay * delay_mult) / 10 private io_16 io_16 db 0 ; do 16-bit i/o? db ? private io_delay_cnt io_delay_cnt dw 1, 0 ; # of NOP spins to do to effect the ; required delay (2000 ns) for the ; worst-case i/o access private iowm_delay_cnt iowm_delay_cnt dw 1, 0 ; # of NOP spins to effect the required ; delay (800 ns) for a write to the ; buffer memory in the window register private inw_fn inw_fn dw OFFSET inwb_8005 ; function to input a word (w/ delay) private outw_fn outw_fn dw OFFSET outwb_8005 ; function to output a word (w/ delay) ; interrupt processing variables private int_test int_test db 0 ; in the initial interrupt testing? private int_tested int_tested db 0 ; was initial interrupt test successful? ifdef DEBUG public ghost_int_c, send_wait_c ghost_int_c dw 0 ; ghost (empty) interrupt counter rx_restart dw 0 ; stalled receiver restart counter send_wait_c dw 0 ; previous send completion wait counter endif extrn THEIR_ISR : dword extrn COUNT_IN_ERR : near extrn COUNT_OUT_ERR : near extrn GET_NUMBER : near extrn MASKINT : near extrn PRINT_NUMBER : near extrn RECV_COPY : near extrn RECV_FIND : near extrn SET_RECV_ISR : near extrn UNMASKINT : near public bad_command_intercept bad_command_intercept: ;called with ah=command, unknown to the skeleton. ;exit with nc if okay, cy, dh=error if not. mov dh,BAD_COMMAND stc ret public AS_SEND_PKT ; Asynchronous packet transmit routine (high-performance drivers only). ; Entry with: ; ES:DI control block pointer ; DS:SI packet to send ; CX packet length ; Interrupts *may* be enabled. Returns: ; ES:DI preserved from call (control block pointer) ; and ; NC if OK ; or ; CY if transmission error ; DH error code ; Interrupt disablement on entry is preserved on exit. AS_SEND_PKT: assume ds:nothing ret public DROP_PKT ; Drop a packet from the queue (high-performance drivers only.) DROP_PKT: assume ds:nothing ret private inb_8005 ; input a byte from an arbitrary 8005 port inb_8005: assume ds:nothing in al, dx io_delay io_delay_cnt ; generic delay ret private inwb_8005 ; input a word from an arbitrary 8005 port -- 8 bit version inwb_8005: assume ds:nothing in al, dx io_delay io_delay_cnt ; generic delay inc dx xchg al, ah in al, dx xchg al, ah io_delay io_delay_cnt ; generic delay dec dx ; to keep 'setport' in synch ret private inw_8005 ; input a word from an arbitrary 8005 port -- 16 bit version inw_8005: assume ds:nothing in ax, dx io_delay io_delay_cnt ; generic delay ret private outb_8005 ; output a byte to an arbitrary 8005 port outb_8005: assume ds:nothing out dx, al io_delay io_delay_cnt ; generic delay ret private outwb_8005 ; output a word to an arbitrary 8005 port -- 8 bit version outwb_8005: assume ds:nothing out dx, al io_delay io_delay_cnt ; generic delay inc dx xchg al, ah out dx, al xchg al, ah io_delay io_delay_cnt ; generic delay dec dx ; to keep 'setport' in synch ret private outw_8005 ; output a word to an arbitrary 8005 port -- 16 bit version outw_8005: assume ds:nothing out dx, ax io_delay io_delay_cnt ; generic delay ret private rcv_mode_1 private rcv_mode_2 private rcv_mode_3 private rcv_mode_5 private rcv_mode_6 ; Receive mode set-up routines. Dispatched to out of the RCV_MODES ; switch (above) or called directly by ETOPEN (once). assume ds:CODE rcv_mode_1: ; turn off receiver call turn_rx_off ret rcv_mode_2: ; only packets to this station address mov ax, MATCH_ONLY ; config 1 mov dx, 0 ; config 2 jmp SHORT rcv_mode_common rcv_mode_3: ; mode 2 plus broadcast packets mov ax, MATCH_BROAD ; config 1 mov dx, CRC_ERR_EN+DRIBBLE_EN+SHORT_FRAME_EN ; config 2 jmp SHORT rcv_mode_common rcv_mode_5: ; mode 3 plus all multicast packets mov ax, MATCH_MULTI ; config 1 mov dx, CRC_ERR_EN+DRIBBLE_EN+SHORT_FRAME_EN ; config 2 jmp SHORT rcv_mode_common rcv_mode_6: ; all packets (promiscuous, including errors) mov ax, MATCH_ALL ; config 1 mov dx, CRC_ERR_EN+DRIBBLE_EN+SHORT_FRAME_EN ; config 2 rcv_mode_common: push dx ; save the changes while we push ax ; wang on the receiver call turn_rx_off ; shut down whilst we play loadport pop bx ; alter the CONFIGURATION 1 register mov ax, config1_r_copy and ax, NOT MATCH_BITS_M or ax, bx mov rcv_errors, 0 cmp bx, MATCH_ALL ; figure if we want to see errors jne rcv_mode_common_1 mov rcv_errors, 1 rcv_mode_common_1: mov config1_r_copy, ax setw_r CONFIG1_R pop bx ; alter the CONFIGURATION 2 register mov ax, config2_r_copy and ax, NOT (CRC_ERR_EN+DRIBBLE_EN+SHORT_FRAME_EN) or ax, bx mov config2_r_copy, ax setw_r CONFIG2_R call turn_rx_on ; drop trou now, brown cow ret private turn_rcv_on ; turn the receiver back on, as per the COMMAND register atop the stack ; removes the COMMAND register upon return rcv_on: assume ds:CODE mov bx, sp ; get former COMMAND register mov ax, ss:[bx+2] test ax, SET_RX_OFF ; see if it's to go back on jnz rcv_on_1 mov command_r, ax ; restore it call turn_rx_on rcv_on_1: ret 2 ; clear stack of COMMAND register too private rcvxmt_off ; forcibly turn off the receiver and/or transmitter -- if the transmitter ; is running, this will abort the transmission ; leaves the prior COMMAND register on top of the stack (for use by a ; matching 'rcv_on' call) rcvxmt_off: assume ds:CODE pop bx ; return address push command_r ; left for 'rcv_on' or command_r, SET_TX_OFF mov transmit, 0 ; not doing it now call turn_rx_off jmp bx ; return public RECV ; Part one of the ISR receive packet processing. Called before interrupt ; acknowledgement. All registers have been saved, DS == CS, and we're ; running on a private stack with interrupts disabled. RECV: assume ds:CODE ifdef DBGINT3 int 03h ; Danger, Will Robinson! endif loadport ; check for and acknowledge the 8005 receive Interrupt ifdef DEBUG getw_r COMSTAT_R test ax, RX_INT jnz recv_1 inc ghost_int_c ; ghost interrupt counter recv_1: endif mov ax, command_r ; acknowledge the Rx Interrupt or ax, RX_INT_ACK setw_r COMSTAT_R cmp int_test, 0 ; is this interrupt a test one? je recv_setup inc int_tested ; indicated tested and be done ret recv_setup: ; set-up DMA access of the buffer read memory mov ax, config1_r_copy ; select BUFFER MEMORY in BUFWIN or ax, BUFFER_MEM_SEL setw_r CONFIG1_R setport DMA_ADDR_R ; code block port state synch ; COME HERE w/ port @ DMA_ADDR_R recv_rcvptr: mov ax, rcv_ptr_copy ; address the next RECEIVE HEADER setw_r DMA_ADDR_R mov ax, command_r ; set the FIFO to READ now or ax, FIFO_READ setw_r COMSTAT_R setport BUFWIN_R ; code block port state synch ; COME HERE w/ port @ BUFWIN_R recv_loop: ; check for an end-of-list header (0 next pointer) getw_r BUFWIN_R ; get the HEADER pointer cmp al, 0 ; check for end of receive list je recv_loop_1 ; looking only at first byte xchg al, ah ; swap to proper host order mov cx, ax ; save pointer away getw_r BUFWIN_R ; get the HEADER & PACKET STATI test al, CHAIN_CONTINUE ; test for completion xchg al, ah ; AL now holds PACKET STATUS byte jnz recv_continue recv_loop_1: jmp recv_done recv_continue: ; process a new frame - compute length and check it push cx ; squirrel away HEADER POINTER sub cx, rcv_ptr_copy ; compute length, checking for wrappage jae recv_continue_1 sub cx, RCV_PTR ; adjust for wrap, sans xmit area recv_continue_1: sub cx, 4 ; less size of 8005 garf cmp cx, ENET_HDR ; < a header is tallied and pitched jb recv_continue_2 cmp cx, GIANT ; > GIANT likewise ja recv_continue_2 test al, SHORT_FRAME+DRIBBLE_ERR+CRC_ERR jz recv_alloc ; no error is a-OK cmp rcv_errors, 0 ; see if we have to allow bad ones jne recv_alloc ; yes, keep this dreck too recv_continue_2: call COUNT_IN_ERR ; tally this error jmp recv_sail_it recv_alloc: ; this one we want - allocate enough space on the stack ; to hold the Ethernet-2 packet header (so we can upcall ; pointing at the type field) mov bx, cx ; save the real length mov cx, ENET_HDR sub sp, cx ; allocate a header on the stack mov di, sp ; and point at it w/ DI mov ax, ss ; set-up ES too mov es, ax cmp io_16, 0 ; do we do it fast or slow? je recv_8bit_hdr sar cx, 1 ; turn into words ; rep insw recv_16bit_hdr: insw ; 16-bit input io_delay iowm_delay_cnt ; reduced delay w/i loop loop recv_16bit_hdr jmp SHORT recv_upcall1 recv_8bit_hdr: ; 8-bit input in al, dx mov es:[di], al inc di loop recv_8bit_hdr recv_upcall1: ;# ; check to make sure this isn't our own broadcast(JLD)(9-25-91) push di mov di, sp ; point at the destination add di, 2 ; which is 2 bytes away(remember push di?) mov ax, 0ffffh mov cx, 6/2 repe scasw jne NotBroadcast push si mov si, offset station_0 mov cx, 6/2 repe cmps word ptr cs:[si], word ptr es:[di] pop si jne NotBroadcast pop di add sp, ENET_HDR ; pop the Ethernet-2 header from stack ; I forgot this until it bit me (11-6) jmp recv_sail_it ; if it's us, bail out! NotBroadcast: pop di ; prepare an upcall with CX == length, ES:DI pointing at type, ; DL == packet class number (V8) mov di, sp ; point at the type field add di, EADDR_LEN*2 mov cx, bx ; get the real length for RECV_FIND push bx ; save the real length push dx ; and save our precious port setup too ;# mov dl, BLUEBOOK ;assume bluebook Ethernet. mov ax, es:[di] xchg ah, al cmp ax, 1500 ja BlueBookPacket inc di ;set di to 802.2 header inc di mov dl, IEEE8023 BlueBookPacket: ;;;; mov dl, BLUEBOOK ; Ethernet-2 'Bluebook' (V8) call RECV_FIND pop dx ; get back port setup pop bx ; and true packet length mov ax, es ; see if the client passed on this one or ax, di jz recv_sail_pop mov si, sp ; prepare to MOVS the Ethernet-2 header mov ax, ss mov ds, ax assume ds:nothing mov cx, ENET_HDR push di ; save client packet base pointer rep movsb pop si ; restore client packet base pointer add sp, ENET_HDR ; pop the Ethernet-2 header from stack mov cx, bx ; compute residual length to bring in sub cx, ENET_HDR cmp io_16, 0 ; do we do it fast or slow? je recv_8bit_data sar cx, 1 ; /2: compute # of words to transfer ; rep insw ; loosely termed "full-bandwidth i/o" recv_16bit_data: insw io_delay iowm_delay_cnt ; reduced delay w/i loop loop recv_16bit_data mov cx, bx ; get length back one more time test bl, 1 ; see if there's a dangling byte jz recv_upcall2 mov cx, 1 ; set-up to fall through to 8-bit recv_8bit_data: in al, dx mov es:[di], al inc di loop recv_8bit_data mov cx, bx ; get length back one more time xor bl, bl ; for sail testing after upcall2 recv_upcall2: ; prepare an upcall with CX == length, DS:SI pointing at ; client-allocated and now filled packet mov ax, es mov ds, ax push dx ; save our precious port setup call RECV_COPY pop dx ; get back port setup mov ax, cs ; and set DS back to CODE mov ds, ax assume ds:CODE ; have to check if 16-bit i/o processed an odd-length packet ; - if so, we MAY have blown the harmony of the 8005 DMA ; (may now be off by one) so just sail it test bl, 1 jnz recv_sail_it pop cx ; pop squirreled next HEADER POINTER mov rcv_ptr_copy, cx ; and make that the new pointer mov al, ch ; update the REA PTR register, making set_r REA_PTR_R ; room for more inbound packets setport BUFWIN_R jmp recv_loop recv_sail_pop: add sp, ENET_HDR ; pop the Ethernet-2 header from stack recv_sail_it: ; rid ourselves of this frame the hard way: by resetting the ; DMA, in addition to our own bookkeeping stuff loadport mov ax, command_r ; release the DMA FIFO or ax, FIFO_WRITE+DMA_INT_ACK setw_r COMSTAT_R pop cx ; pop squirreled next HEADER POINTER mov rcv_ptr_copy, cx ; and make that the new pointer mov al, ch ; update the REA PTR register, making set_r REA_PTR_R ; room for more inbound packets setport DMA_ADDR_R jmp recv_rcvptr recv_done: ; all inbound frames processed loadport mov ax, command_r ; release the DMA FIFO or ax, FIFO_WRITE+DMA_INT_ACK setw_r COMSTAT_R ; restart a stalled receiver getw_r COMSTAT_R ; grab the STATUS register test ax, RX_ON ; receiver still on? jnz recv_done_1 ifdef DEBUG inc rx_restart endif call turn_rx_on recv_done_1: ret public RECV_EXITING ; Part two of the ISR receive packet processing. Called after interrupts ; have been acknowledged. Only DS and AX have been saved, DS == CS and ; we're running on the original stack (i.e. not the private one). On ; entry, interrupts are still disabled but it is possible to intelligently ; turn them back on. RECV_EXITING: assume ds:CODE ret public RESET_INTERFACE ; Reset the interface. RESET_INTERFACE: assume ds:CODE loadport mov ax, RESET setw_r CONFIG2_R ; wait a good, long while mov ax, 1 call set_timeout RESET_INTERFACE_1: call do_timeout jnz RESET_INTERFACE_1 ;;;; ; delay another 4 microseconds ;;;; io_delay io_delay_cnt ; generic delay ;;;; io_delay io_delay_cnt ; generic delay ret private turn_rx_off ; Turn off the receiver portion of the device. Undoes 'turn_rx_on'. turn_rx_off: assume ds:CODE loadport mov ax, command_r and ax, NOT RX_INT_EN or ax, SET_RX_OFF mov command_r, ax setw_r COMSTAT_R ret private turn_rx_on ; Turn on the receiver portion of the device. Assumes the station address ; has already been programmed, receive ISR registered, etc. Just brings it ; all to life on the wire. Undone by 'turn_rx_off'. turn_rx_on: assume ds:CODE loadport ; load up Receive End Area Pointer mov al, TEA_INIT + 1 set_r REA_PTR_R ; load up the Receive Pointer Register mov ax, RCV_PTR setw_r RX_PTR_R mov rcv_ptr_copy, ax ; now turn it on mov ax, command_r and ax, NOT SET_RX_OFF or ax, RX_INT_EN mov command_r, ax or ax, SET_RX_ON setw_r COMSTAT_R ret public SEND_PKT ; Send one packet. Entry with: ; DS:SI packet buffer to xmit ; CX packet length ; ES:DI upcall routine (0:0 if no upcall is desired) -- only supported ; if the high-performance bit is set in 'driver_function' byte ; Returns: ; NC if OK ; or ; CY if transmission error ; DH error code SEND_PKT: assume ds:nothing ifdef DBGINT3 int 03h ; Danger, Will Robinson! endif mov ax, ds ; restore DS usage right here, saving mov es, ax ; it in ES (as we don't do upcalls) mov ax, cs mov ds, ax assume ds:CODE cmp cx, ENET_HDR ; firewall against trivia jae SEND_PKT_1 jmp send_pkt_ret SEND_PKT_1: cmp cx, GIANT ; see if too big jbe SEND_PKT_2 jmp send_pkt_NOSPACE SEND_PKT_2: cmp cx, RUNT ; see if too small jae SEND_PKT_3 ; ... sounds like the Three Bears mov cx, RUNT ; transmit at least this much SEND_PKT_3: ; mask receiver interrupts (note the receiver is still ; running however) -- this also arbitrates use of the FIFO push cx ; push stuff so MASKINT won't bite us mov al, INT_NO call MASKINT loadport mov ax, config1_r_copy ; select BUFFER MEMORY in BUFWIN or ax, BUFFER_MEM_SEL setw_r CONFIG1_R ; check status of the previous transmission cmp transmit, 0 ; see if a transmit is incomplete je send_pkt_load send_pkt_wait: loadport ; synch for the loop mov ax, 3 ; address the TRANSMIT STATUS byte setw_r DMA_ADDR_R mov ax, command_r ; set the FIFO to READ now, also or ax, FIFO_READ+TX_INT_ACK ; ACKs any TX int bit setw_r COMSTAT_R get_r BUFWIN_R ; get the STATUS byte mov bl, al ; save the gotten STATUS byte mov ax, command_r ; set the FIFO back to WRITE (aborts, or ax, FIFO_WRITE+DMA_INT_ACK ; drains, ACKs FIFO int bit) setw_r COMSTAT_R test bl, HDR_DONE ; check for transmit done ifdef DEBUG jnz send_pkt_wait_1 inc send_wait_c ; count send completion waits jmp send_pkt_wait ; loop send_pkt_wait_1: else jz send_pkt_wait ; loop endif ; done -- check for transmit error & count if so test bl, BABBLE_ERR+COLL_16_ERR jz send_pkt_load call COUNT_OUT_ERR ; count the error send_pkt_load: ; load the new packet into the transmit area pop cx ; revive stuff pushed for MASKINT ; load up the transmit buffer -- allows only a single ; transmit (doesn't chain 'em); however, this transmission ; is overlapped with the preparation of the next loadport ; synch the state xor ax, ax ; TRANSMIT NEXT HEADER word setw_r DMA_ADDR_R mov ax, cx ; calculate xmit request length add ax, 4 ; including 8005 garf xchg ah, al ; SWAP setw_r BUFWIN_R mov al, PACKET_PRESENT+DATA_FOLLOWS ; TRANSMIT COMMAND byte xor ah, ah ; TRANSMIT STATUS byte setw_r BUFWIN_R ; both in one SWAPPED swoop ; semi-quick programmed output here -- direct use of macros mov ax, es ; go back to DS-relative packet data mov ds, ax assume ds:nothing cmp io_16, 0 ; can do 16-bit i/o? je send_pkt_8bit test cx, 1 ; odd length? jz send_pkt_load_1 inc cx ; make even for 16-bit mode output send_pkt_load_1: sar cx, 1 ; /2: compute # of words to transfer cmp iowm_delay_cnt, 0 ; check for full-tilt boogie jne send_pkt_load_2 ; nope, need delays rep outsw ; blow-out clearance i/o jmp SHORT send_pkt_xmt send_pkt_load_2: mov ax, [si] ; Note: DS-relative packet here out dx, ax io_delay iowm_delay_cnt ; reduced delay w/i loop inc si inc si loop send_pkt_load_2 jmp SHORT send_pkt_xmt ; done w/ buffer load send_pkt_8bit: ; 8 bit packet load cmp iowm_delay_cnt, 0 ; check for full-tilt boogie jne UpHere_1 ; nope, need delays ;the following replaces rep outsb, which doesn't work too well on 8088-based PCs ;; rep outsb ; blow-out clearance i/o UpHere: lodsb ; Note: DS-relative packet here out dx, al loop UpHere jmp SHORT send_pkt_xmt UpHere_1: mov al, [si] ; Note: DS-relative packet here out dx, al io_delay iowm_delay_cnt ; reduced delay w/i loop inc si loop UpHere_1 send_pkt_xmt: ; packet now loaded, finish up and transmit it mov ax, cs ; restore our DS mov ds, ax assume ds:CODE ; set TRANSMIT POINTER (overlap as FIFO drains) xor ax, ax ; start chain at address 0 setw_r TX_PTR_R ; wait for DMA FIFO to drain fifo_wait ; now transmit it mov ax, command_r ; remove default transmitter off cmd and ax, NOT SET_TX_OFF mov command_r, ax or ax, SET_TX_ON setw_r COMSTAT_R ; Send! mov transmit, 1 ; note to check completion next time ; unmask receiver interrupts, releasing FIFO mov al, INT_NO call UNMASKINT send_pkt_ret: clc ; OK ret send_pkt_NOSPACE: mov dh, NO_SPACE stc ; error ret public SET_ADDRESS ; Set the MAC station receiver address. Entry with: ; DS:SI the new MAC address to adopt ; CX length of address at DS:SI ; Returns: ; DS restored to point at CODE segment ; plus ; NC if OK ; or ; CY if error ; DH error code SET_ADDRESS: assume ds:nothing mov ax, ds ; undo the twisted DS usage mov es, ax ; back to addressing our memory mov ax, cs mov ds, ax assume ds:CODE cmp cx, EADDR_LEN ; check for proper address length jne set_addr_BADADDRESS test BYTE PTR es:[si], 1 ; deny broadcast or multicast jnz set_addr_BADADDRESS ;# ; set the new station address (JLD)(9-25-91) mov ax, ds:[si][0] mov word ptr ds:station_0[0], ax mov ax, ds:[si][2] mov word ptr ds:station_0[2], ax mov ax, ds:[si][4] mov word ptr ds:station_0[4], ax ; disable receiver and/or transmitter call rcvxmt_off ; leaves COMMAND register on stack ; set the new station address loadport mov ax, config1_r_copy ; select STATION address reg 0 or ax, STATION_0_SEL setw_r CONFIG1_R xor ax, ax setw_r DMA_ADDR_R setport BUFWIN_R ; fix access within the loop SET_ADDRESS_1: mov al, es:[si] ; output bytes of the new address inc si set_r BUFWIN_R loop SET_ADDRESS_1 ; reenable the receiver if it was on before call rcv_on ; removes COMMAND register from stack clc ; OK ret set_addr_BADADDRESS: mov dh, BAD_ADDRESS ; improper address stc ; error ret public set_multicast_list set_multicast_list: ;enter with ds:si ->list of multicast addresses, ax = number of addresses, ; cx = number of bytes. assume ds:CODE jmp SHORT set_multicast_err ; FOR NOW: no multicast support clc ; OK ret set_multicast_err: mov dh, NO_MULTICAST stc ; error ret public TERMINATE ; Terminate the packet driver. Nothing special to do. TERMINATE: assume ds:CODE ret public XMIT ; Routine to process a queued transmission with the least possible latency. ; Called immediately within the receive ISR. The attempt here is to effect ; back-to-back transmissions. This routine may only use AX and DX freely ; and is running whatever stack exists at interrupt time (not the private ; one). This routine isn't necessary on the 8005, because it can chain ; transmissions (if anyone really cared). XMIT: assume ds:nothing ret include popf.asm include timeout.asm ; Everything above this line is resident upon successful load. public timer_isr timer_isr: ;if the first instruction is an iret, then the timer is not hooked iret ;any code after this will not be kept. Buffers used by the program, if any, ;are allocated from the memory between end_resident and end_free_mem. public end_resident,end_free_mem end_resident label byte end_free_mem label byte ; Everything below this line is discarded upon installation. public USAGE_MSG USAGE_MSG db "usage: davidsys [options] <packet_int_no> <hardware_irq> <io_addr> <delay_mult>",CR,LF,'$' public COPYRIGHT_MSG COPYRIGHT_MSG db "Packet driver for the Ether-T PC/AT ",'0'+(majver / 10),'0'+(majver mod 10),".",'0'+version,".",'0'+s8005_version,CR,LF db "Portions Copyright 1991 DAVID Systems, Inc and Marc S Dye",CR,LF,'$' badint_msg db "Specified device interrupt not supported for" db " your installation",CR,LF,'$' int8_msg db " Try: 2, 3, 4, 5, 6, or 7",CR,LF,'$' int16_msg db " Try: 3, 4, 5, 6, 7, 9, 10, 11, 12, 14, or 15" db CR,LF,'$' inttimedout_msg db "Timed out awaiting device test interrupt",CR,LF,'$' nodev_msg db "No device found at specified i/o address",CR,LF,'$' setaddr_msg db "Unable to set initial station address",CR,LF,'$' delay_mult_name db "Delay multipler (x10) ",'$' int_no_name db "Interrupt number ",'$' io_addr_name db "I/O port ",'$' ifdef DEBUG count_del_name db "Incremental i/o delay spin (nsec x10) ",'$' delay_del_name db "Basic i/o delay (nsec x100) ",'$' io_delay_name db "I/O delay (spins) ",'$' iowm_delay_name db "I/O write memory delay (spins) ",'$' null_bias_name db "Null (overhead) cost (nsec x100) ",'$' null_spin_name db "Null spin count ",'$' ref_spin_name db "Reference spin count ",'$' unit_spin_name db "Single spin count ",'$' endif ;-> the assigned Ethernet address of the card. extrn rom_address: byte private int_map ; Interrupt number to Ether-T PC/AT configuration register code mapping table ; 0 1 2 3 4 5 6 7 int_map db 00h, 00h, 02h, 01h, 03h, 04h, 05h, 06h ; 8 9 10 11 12 13 14 15 db 00h, 02h, 07h, 08h, 09h, 00h, 0Ah, 0Bh REF_DELAY equ 64 private count_delay count_delay dw ?, 0 ; # of 10 nsecs in each io_delay spin private delay_delay delay_delay dw ?, 0 ; # of 100 nsecs in the basic io_delay private null_bias null_bias dw ?, 0 ; # of 100 nsecs in a null spin private null_spins null_spins dw ?, 0 ; # of spins for without io_delay macro private ref_spins ref_spins dw ?, 0 ; # of spins for io_delay of 1+REF_DELAY private test_delay test_delay dw ? ; holding tank for current sample count private unit_spins unit_spins dw ?, 0 ; # of spins for io_delay of 1 ; macro to sample timer zero's counter register timer0_sample macro xor al, al ; latch timer zero counter out 43h, al in al, 40h ; sample timer zero counter mov ah, al in al, 40h xchg ah, al endm private calibrate_one calibrate_one: assume ds:CODE mov test_delay, ax ; find the timer near zero mov cx, 100h calibrate_one_1: timer0_sample cmp ax, cx ja calibrate_one_1 ; now find the timer above that value (after wrapping to max) calibrate_one_2: timer0_sample cmp ax, cx jbe calibrate_one_2 ; wait till it gets to the one quarter point mov cx, 0C000h calibrate_one_3: timer0_sample cmp ax, cx ja calibrate_one_3 ; calibration time - disable interrupts, watch for half a ; clock period to elapse pushf cli xor bx, bx mov cx, 4000h cmp test_delay, 0 ; see if measuring overhead? jne calibrate_io ; calibrating the overhead of this timing stuff only calibrate_one_4: inc bx jc calibrate_exit ; overflow - exit w/ 0 timer0_sample cmp ax, cx ja calibrate_one_4 jmp SHORT calibrate_exit calibrate_io: io_delay test_delay inc bx jc calibrate_exit ; overflow - exit w/ 0 timer0_sample cmp ax, cx ja calibrate_io calibrate_exit: popf mov ax, bx ret private calibrate_delay calibrate_delay: assume ds:CODE ; if user wanted no delays, skip all this stuff cmp delay_mult, 0 jne calibrate_delay_1 xor ax, ax ; normalize to zero jmp calibrate_store calibrate_delay_1: ; calibrate the overhead of the time sampling loop xor ax, ax call calibrate_one or ax, ax jz calibrate_dj ; can't time -- default it all mov null_spins, ax ifdef DEBUG mov di, OFFSET null_spins mov dx, OFFSET null_spin_name call PRINT_NUMBER endif ; calibrate a unit (single spin) loop mov ax, 1 call calibrate_one or ax, ax jz calibrate_dj ; can't time -- default it mov unit_spins, ax ifdef DEBUG mov di, OFFSET unit_spins mov dx, OFFSET unit_spin_name call PRINT_NUMBER mov ax, unit_spins ; reload AX endif cmp null_spins, ax ; ensure null >= unit jb calibrate_dj ; bogonic -- default it ; now one with some teeth in it mov ax, 1+REF_DELAY call calibrate_one or ax, ax jz calibrate_dj ; can't time -- default it all mov ref_spins, ax ifdef DEBUG mov di, OFFSET ref_spins mov dx, OFFSET ref_spin_name call PRINT_NUMBER mov ax, ref_spins ; reload AX endif cmp unit_spins, ax ; ensure unit > ref ja calibrate_dj_1 calibrate_dj: jmp SHORT calibrate_def ; bogonic -- default it calibrate_dj_1: ; now do the math - compute the overhead of the timing code ; (in units of 100 nsec) mov cx, null_spins call compute_100nsecs jc calibrate_def mov null_bias, ax ifdef DEBUG mov di, OFFSET null_bias mov dx, OFFSET null_bias_name call PRINT_NUMBER endif ; compute cost of the basic i/o delay macro (in units of ; 100 nsec) mov cx, unit_spins call compute_100nsecs jc calibrate_def sub ax, null_bias mov delay_delay, ax ifdef DEBUG mov di, OFFSET delay_delay mov dx, OFFSET delay_del_name call PRINT_NUMBER endif ; compute cost of the reference spin in the i/o delay ; macro (this time, in units of 10 nsec) mov cx, ref_spins call compute_100nsecs jc calibrate_def sub ax, null_bias sub ax, delay_delay ; now delay for REF_COUNT spins mov cx, 10 mul cx jnc calibrate_dj_2 ; this machine is *sooo* slow, a minimum delay is fine mov ax, 1 jmp SHORT calibrate_store calibrate_dj_2: mov cx, REF_DELAY div cx mov count_delay, ax ifdef DEBUG mov di, OFFSET count_delay mov dx, OFFSET count_del_name call PRINT_NUMBER endif ; now, see if basic i/o delay (w/o extra spins) is enough mov bx, 1 ; basic macro includes one spin mov ax, delay_delay sub ax, 22 ; >= 2.2 usec ? jae calibrate_dj_3 neg ax ; correct sign of residual mov cx, 10 ; scale to 10 nsec units mul cx jc calibrate_def div count_delay inc ax add bx, ax ; back into spin count result calibrate_dj_3: mov ax, bx ; the calibrated basic result jmp SHORT calibrate_store calibrate_def: ; this processor is *sooo* fast that we can't calibrate it!? ; just use a conservative default (should be good to about a ; 400MHz 80486) mov ax, 120 ; scale the delay by the user-request multiplier (if any) calibrate_store: mul delay_mult ; a tens multiple mov cx, 10 ; so reduce / 10 div cx ; allowed to be zero mov io_delay_cnt, ax ; compute the .9 usec 'iowm_delay_cnt' mov cx, 9 mul cx mov cx, 20 div cx mov iowm_delay_cnt, ax ret private compute_100nsecs ; Given a value in CX (representing spin counter during a 1/36.04 timing ; run), compute the number of hundreds of nanoseconds per unit spin. Return ; result in AX, or set CY and return if algorithm won't scale. compute_100nsecs: assume ds:CODE mov ax, 9 ; compute spins * 9 (36.04/4) mul cx jc compute_100n_err ; won't fit -- return error mov cx, ax ; prepare for division mov dx, 26h ; put 2,500,000 into DX,AX mov ax, 25a0h div cx ; compute 10M / (spins*36.04) clc ret compute_100n_err: ret public ETOPEN ; Perform initial open of the device. Called only once: immediately prior to ; hooking the packet driver service interrupt and TSRing. Device interrupts ; are to be hooked (if this routine deems reasonable to do so). No registers ; are given on entry. On return: ; NC if OK ; DX offset of the end of the resident portion of the driver ; or ; CY if error ETOPEN: assume ds:CODE ifdef DBGINT3 int 03h ; Danger, Will Robinson! endif ; calibrate the i/o delays needed call calibrate_delay ifdef DEBUG mov di, OFFSET io_delay_cnt mov dx, OFFSET io_delay_name call PRINT_NUMBER mov di, OFFSET iowm_delay_cnt mov dx, OFFSET iowm_delay_name call PRINT_NUMBER endif ; test for access to the device; check for 16-bit i/o call try_io jnc ETOPEN_1 jmp etopen_err ETOPEN_1: ; try out the interrupt channel & leave hooked if successful call try_interrupt jnc ETOPEN_2 jmp etopen_err ETOPEN_2: ; get the PROM Ethernet address call RESET_INTERFACE ; reset the device (again!) loadport mov ax, command_r ; everything still off or ax, FIFO_WRITE setw_r COMSTAT_R xor ax, ax ; reset the DMA address to 0 setw_r DMA_ADDR_R mov ax, config1_r_copy ; select the PROM or ax, PROM_SEL setw_r CONFIG1_R mov ax, config2_r_copy ; blast the watchdog or ax, KILL_WATCHDOG setw_r CONFIG2_R push ds pop es mov di,offset rom_address setport BUFWIN_R ; fix access within the loop mov cx, EADDR_LEN ; allocate some space for the address ETOPEN_3: get_r BUFWIN_R ; next byte of PROM Ethernet address stosb loop ETOPEN_3 ; set the PROM address as the default STATION 0 address call RESET_INTERFACE ; reset the device (yet again!) mov cx, EADDR_LEN ; size of Ethernet address mov si, offset rom_address call SET_ADDRESS ; load up Transmit End Area Pointer loadport mov ax, config1_r_copy or ax, TEA_SEL setw_r CONFIG1_R mov al, TEA_INIT set_r BUFWIN_R ; set up a few other default goodies once only here: ; config 1 : STATION 0 address (Matchmode by 'rcv_mode_3') ; config 2 : defaults are OK or config1_r_copy, STATION_0_EN mov ax, config1_r_copy setw_r CONFIG1_R ; we're go now -- wake up and smell the roses! and command_r, NOT SET_RX_OFF ; reload the CARD CONFIGURATION register mov ax, config1_r_copy ; select CARD CONFIGURATION register or ax, CARD_CONFIG_SEL setw_r CONFIG1_R mov al, cardconfig_r set_r BUFWIN_R ; writes CARD CONFIGURATION register ; turn on the receiver now, in (default) mode 3 call rcv_mode_3 clc ; OK ret etopen_err: stc ; error ret public PARSE_ARGS ; Parse the device-specific portion of the invokation command line (after ; the packet driver vector number). Entry with: ; DS:SI residual command line ; Can emit device-specific bitches as necessary (using DOS i/o) and exit ; without returning. If it returns: ; NC if OK ; or ; CY if usage error ; Returning w/ carry set will cause a usage error, then exit without further ; processing. PARSE_ARGS: assume ds:CODE mov di, OFFSET INT_NO call GET_NUMBER mov di, OFFSET IO_ADDR call GET_NUMBER mov di, OFFSET delay_mult call GET_NUMBER clc ; OK ret public PRINT_PARAMETERS ; Spew out all of the configuration parameters to the console device. ; Called within the main program, just prior to deciding to TSR. Should ; dump out each device-specific parameter, parsed by PARSE_ARGS (just to ; make the user warm-and-fuzzy I suppose...) Entry with: ; no special register contents ; Returns: ; nothing PRINT_PARAMETERS: assume ds:CODE mov di, OFFSET INT_NO mov dx, OFFSET int_no_name call PRINT_NUMBER mov di, OFFSET IO_ADDR mov dx, OFFSET io_addr_name call PRINT_NUMBER mov di, OFFSET delay_mult mov dx, OFFSET delay_mult_name call PRINT_NUMBER ret private try_interrupt ; try out the receiver interrupt (once at the outset); in the process, ; sets up the CARD CONFIGURATION register try_interrupt: assume ds:CODE call RESET_INTERFACE loadport mov ax, config1_r_copy ; program CARD CONFIGURATION register or ax, CARD_CONFIG_SEL setw_r CONFIG1_R ; map interrupt number to card config enumeration value mov bx, WORD PTR INT_NO mov al, [bx + OFFSET int_map] or al, al jz try_int_badint_err ; check for 16-bit i/o usage; include in card config value cmp io_16, 0 je try_interrupt_1 or al, SET_16BITMODE_M try_interrupt_1: set_r BUFWIN_R ; writes CARD CONFIGURATION register mov cardconfig_r, al ; save soft-copy of this ; install the 'recv_isr' handler mov int_test, 1 ; flag that we're testing only call SET_RECV_ISR ; cause a receiver interrupt loadport mov ax, command_r ; SET_RX_OFF in here now or ax, RX_INT_EN+SET_RX_ON setw_r COMSTAT_R ; Interrupt! ;# Compaq DOS leaves CPU ints disabled! sti mov ax, 1 ; wait one tick call set_timeout try_interrupt_2: call do_timeout jz try_int_timedout cmp int_tested, 0 ; did it happen? je try_interrupt_2 ; the interrupt worked -- leave w/ the receiver off, the ; ISR hooked but masked mov ax, command_r ; SET_RX_OFF in here now setw_r COMSTAT_R ; shut up! mov al, INT_NO call MASKINT mov int_test, 0 ; from now on, it's the real thing clc ; OK ret try_int_timedout: ; timed-out (bummer dude!) -- turn receiver back off mov ax, command_r ; SET_RX_OFF in here now or ax, RX_INT_ACK ; just in case ... setw_r COMSTAT_R ; shut up! ; deregister handler and boogie ; This should be a standard call -- I've asked Russ ... mov al, INT_NO add al, 8 cmp al, 8+8 ; is it a slave 8259 interrupt? jb try_int_timedout_1; no. add al, 70h - (8+8) ; map it to the real interrupt try_int_timedout_1: push ds assume ds:nothing lds dx, THEIR_ISR mov ah, 25h int 21h pop ds assume ds:CODE mov dx, OFFSET inttimedout_msg jmp SHORT try_int_err try_int_badint_err: mov dx, OFFSET badint_msg mov ah, 9 ; blab to the user int 21h cmp io_16, 0 ; tell him/her/it what's legit jne try_int_badint_err_1 mov dx, OFFSET int8_msg jmp SHORT try_int_err try_int_badint_err_1: mov dx, OFFSET int16_msg try_int_err: stc ; error ret private try_io ; try out i/o to the device; in the process, determines if 16-bit i/o is OK ; NOTE: This code was transliterated from the C source for DAVID's NDIS driver. ; In the absence of any written documentation on the CARD CONFIGURATION ; register, the many magic numbers herein remain a mystery. try_io: assume ds:CODE call RESET_INTERFACE mov command_r, SET_TX_OFF+SET_RX_OFF+SET_DMA_OFF loadport mov ax, config1_r_copy ; select CARD CONFIGURATION register or ax, CARD_CONFIG_SEL set_r CONFIG1_R ; BYTE-size only here! ; first taunting of the device ... mov al, 05h ; C sez: "4 bit is LSBS value" set_r BUFWIN_R ; " ... and ... " get_r BUFWIN_R ; C sez: "comes back in the 4 MSBs" and al, 0F0h cmp al, 50h ; this has to compare jne try_io_err ; second taunting of the device ... mov al, 0Ah ; "Your mother was a hamster ..." set_r BUFWIN_R get_r BUFWIN_R ; "... and your father smelt of" and al, 0F0h ; "ELDERBERRIES!" cmp al, 0A0h jne try_io_err ; now for something completely different -- ask the CARD ; CONFIGURATION register if it's plugged into an 8- or ; 16-bit slot; mark it well get_r BUFWIN_R and al, 1 ; bit on means 8-bit slot xor al, 1 ; complement sense for 'io_16' mov io_16, al jz try_io_1 ; set-up 16-bit versions of word i/o functions ; N.B. From this point forward, we MUST to 16 bit i/o ; on 16 bit objects if the card told us to! mov inw_fn, OFFSET inw_8005 ; input function mov outw_fn, OFFSET outw_8005 ; output function try_io_1: clc ; OK ret try_io_err: mov dx, OFFSET nodev_msg stc ; error ret ; "Now go away or I shall taunt you a second time-uh!" CODE ends end ; eof