Columbia Kermit/kermit.zip/archives/packetdrivers.tar.gz/pd.tar/src/ubnicpc.asm

Assembly Source File | 1995-06-25 | 16KB | 688 lines

version    equ    1

;History:525,47 0

; Copyright, 1990-1992, Russell Nelson, Crynwr Software

;   This program is free software; you can redistribute it and/or modify
;   it under the terms of the GNU General Public License as published by
;   the Free Software Foundation, version 1.
;
;   This program is distributed in the hope that it will be useful,
;   but WITHOUT ANY WARRANTY; without even the implied warranty of
;   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;   GNU General Public License for more details.
;
;   You should have received a copy of the GNU General Public License
;   along with this program; if not, write to the Free Software
;   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.


    include    defs.asm

;some generic information about buffer lengths, etc
XMITBUF_LEN    equ    800h        ;Transmit buffer length
RPAGE_LEN    equ    128        ;receive page is 128 bytes
NUM_RPAGES    equ    96        ;There are 96 receive pages
NUM_XBUFS    equ    2        ;Number of xmit buffers
NUM_XBUFS_MASK    equ    1

ub_seg    segment at 0

    org    10h
eaddr_rom    db    6 dup(?)    ;Has serial # in 3 & 4th bytes

    org    2080h
tsa_msb        db    ?    ;transmitter start address, high order 4
                ;bits on write, start send on read
tsa_lsb        db    ?    ;Transmitter start address, least
                ;significant byte on write, clear PAV
                ;on read

;Control / status register (CSR)

csr        db    ?    ;Control on write, status on read port

;Command bits
TxRdyIntEn    equ    080h        ;allow TxRdy interrupts
PAVIntEn    equ    040h        ;Allow PAV to gen. intr.
SFTInt        equ    020h        ;generate an interrupt reg.
TimIntEn    equ    010h        ;allow Time interrupt req.
;status bits
NTxRdyInt    equ    080h        ;Not req. TxRdy inter.
NPAVInt        equ    040h        ;Not req. Pav intr.
NSFTInt        equ    020h        ;Not req. SFTInt inter.
NTimInt        equ    010h        ;Not req. timer inter.
NRINT        equ    008h        ;Not req. recv inter.
NTINT        equ    004h        ;Not req. xmit inter.
TPOK        equ    002h        ;Packet okay of some type
TXDONE        equ    001h        ;Transmit done

;Page pointer register definitions

ffp        label    byte        ;ffp - first free page register
epp        label    byte        ;epp - empty page pointer register
pp        db    ?        ;ffp on write/epp on read


;ffp bits
NIC_IE        equ    080h        ;NIC interrupts enable

;epp bits
PAV        equ    080h        ;Page available
RPAGE_BITS    equ    07fh


    org    2100h
page_ram    db    NUM_RPAGES dup(?);Receiver buffer pages

    org    2180h
tstatus        db    ?        ;Transmitter status 80

;Transmit status bits - EDLC
TX_READY    equ    080h        ;
TX_BUSY        equ    040h        ;Carrier detect
TX_TPR        equ    020h        ;Self received packet sent
TX_SHORTED    equ    010h        ;Carrier lost
TX_UF        equ    008h        ;Underflow
TX_COL        equ    004h        ;Collision
TX_C16        equ    002h        ;16 collisions
TX_PE        equ    001h        ;Parity error

TXERRMASK    equ    TX_PE or TX_C16 or TX_COL or TX_UF or TX_SHORTED or TX_BUSY

tmask        db    ?        ;Transmitter mask 81
rstatus        db    ?        ;Receiver status
rmask        db    ?        ;Receiver mask 83
tmode        db    ?        ;Transmitter mode 84
rmode        db    ?        ;Receiver mode 85
reset        db    ?        ;Reset line - high on bit 7, 86
tdrlsb        db    ?        ;TDR lsb  87
eaddr_ram    db    6 dup(?)    ;current Ethernet address.
        db    ?        ;Reserved 8e
tdrmsb        db    ?        ;TDR msb 8f

    org    4000h
receive_buf    label    byte

    org    7000h
transmit_buf_1    label    byte

    org    7800h
transmit_buf_2    label    byte

ub_seg    ends

code    segment    word public
    assume    cs:code, ds:code

    public    int_no
int_no        db    3,0,0,0        ;must be four bytes long for get_number.
base_addr    dw    0d000h,0

    public    driver_class, driver_type, driver_name, driver_function, parameter_list
driver_class    db    BLUEBOOK, IEEE8023, 0        ;from the packet spec
driver_type    db    8        ;from the packet spec
driver_name    db    'PC-NIC',0    ;name of the driver.
driver_function    db    2
parameter_list    label    byte
    db    1    ;major rev of packet driver
    db    9    ;minor rev of packet driver
    db    14    ;length of parameter list
    db    EADDR_LEN    ;length of MAC-layer address
    dw    GIANT    ;MTU, including MAC headers
    dw    MAX_MULTICAST * EADDR_LEN    ;buffer size of multicast addrs
    dw    0    ;(# of back-to-back MTU rcvs) - 1
    dw    0    ;(# of successive xmits) - 1
int_num    dw    0    ;Interrupt # to hook for post-EOI
            ;processing, 0 == none,

    public    rcv_modes
rcv_modes    dw    7        ;number of receive modes in our table.
        dw    0               ;There is no mode zero
        dw    rcv_mode_1
        dw    0        ;don't want to bother.
        dw    rcv_mode_3
        dw    0        ;haven't set up perfect filtering yet.
        dw    rcv_mode_5
        dw    rcv_mode_6

current_page    db    0        ;current receiver page

active_buffer    dw    transmit_buf_1
inactive_buffer    dw    transmit_buf_2

    include    movemem.asm

    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
; The Asynchronous Transmit Packet routine.
; Enter with es:di -> i/o control block, ds:si -> packet, cx = packet length,
;   interrupts possibly enabled.
; Exit with nc if ok, or else cy if error, dh set to error number.
;   es:di and interrupt enable flag preserved on exit.
as_send_pkt:
    ret

    public    drop_pkt
; Drop a packet from the queue.
; Enter with es:di -> iocb.
drop_pkt:
    assume    ds:nothing
    ret

    public    xmit
; Process a transmit interrupt with the least possible latency to achieve
;   back-to-back packet transmissions.
; May only use ax and dx.
xmit:
    assume    ds:nothing
    ret


    public    send_pkt
send_pkt:
;enter with es:di->upcall routine, (0:0) if no upcall is desired.
;  (only if the high-performance bit is set in driver_function)
;enter with ds:si -> packet, cx = packet length.
;if we're a high-performance driver, es:di -> upcall.
;exit with nc if ok, or else cy if error, dh set to error number.
    assume    ds:nothing

    mov    es,base_addr
    assume    es:ub_seg

    cmp    cx,GIANT        ; Is this packet too large?
    ja    send_pkt_toobig

    cmp    cx,RUNT            ; minimum length for Ether
    jnb    oklen
    mov    cx,RUNT            ; make sure size at least RUNT
oklen:

    mov    di,XMITBUF_LEN        ;compute where we're going to
    sub    di,cx            ;  be putting the packet.

;games above ensure that the last byte of data to go out is at the
;end of the ub xmit buffer, pos is really the offset from the
;start of that buffer

    mov    ax,active_buffer    ;swap the buffer pointers.
    xchg    ax,inactive_buffer
    mov    active_buffer,ax
    add    di,ax
    push    di
    call    movemem
    pop    di

;Wait for previous packet to finish first
;could do this with interrupts, etc, but with only 2 xmit buffers
;doesn't seem worth the effort

send_pkt_1:
    mov    al,csr
    and    al,TPOK or TXDONE
    cmp    al,TPOK or TXDONE
    jne    send_pkt_1

    mov    al,tstatus        ;get xmiter status ...
    mov    tstatus,0fh        ;... and clear status bits

    test    al,TXERRMASK        ;any errors?
    je    send_pkt_2
    call    count_out_err        ;yes, count them.
send_pkt_2:

;all done above, we can play with TSA now!
;give offset

    mov    ax,di
    mov    tsa_lsb,al
    mov    tsa_msb,ah

    cmp    al,tsa_msb        ;Start the send in action (SIDEEFFECT)

    clc
    ret
send_pkt_toobig:
    mov    dh,NO_SPACE
    stc
    ret

    public    set_address
set_address:
;enter with ds:si -> Ethernet address, CX = length of address.
;exit with nc if okay, or cy, dh=error if any errors.
    assume    ds:code
    cmp    cx,EADDR_LEN        ;ensure that their address is okay.
    je    set_address_4
    mov    dh,BAD_ADDRESS
    stc
    jmp    short set_address_done
set_address_4:

    mov    es,base_addr
    mov    di,offset eaddr_ram
    rep    movsb
;    call    initialize        ;initialize with our new address.

set_address_okay:
    mov    cx,EADDR_LEN        ;return their address length.
    clc
set_address_done:
    ret


;    0 - accept no packets
rcv_mode_1:
    mov    es,base_addr
    assume    es:ub_seg

    mov    rmode,0
    ret

rcv_mode_3:
;    1 - accept node id packets, multicasts which match first three
;        bytes of node id, and broadcasts
    mov    es,base_addr
    assume    es:ub_seg

    mov    rmode,1
    ret

;    2 - accept node id packets, all multicasts and broadcasts
rcv_mode_5:
    mov    es,base_addr
    assume    es:ub_seg

    mov    rmode,2
    ret

;    3 - take all, promiscous
rcv_mode_6:
    mov    es,base_addr
    assume    es:ub_seg

    mov    rmode,3
    ret

    public    set_multicast_list
set_multicast_list:
;enter with ds:si ->list of multicast addresses, cx = number of addresses.
;return nc if we set all of them, or cy,dh=error if we didn't.
    mov    dh,NO_MULTICAST
    stc
    ret


    public    terminate
terminate:
    mov    es,base_addr
    assume    es:ub_seg

    mov    ffp,0            ;set ffp to zero - disabling PAV
    mov    csr,0            ;Turn off interrupt masks here and ...
    mov    tmask,0            ;reset edlc interrupt masks
    mov    rmask,0
    mov    reset,80h        ;Turn on reset line

    ret

    public    reset_interface
reset_interface:
;reset the interface.
    assume    ds:code
    ret


;called when we want to determine what to do with a received packet.
;enter with cx = packet length, es:di -> packet type, dl = packet class.
    extrn    recv_find: near

;called after we have copied the packet into the buffer.
;enter with ds:si ->the packet, cx = length of the packet.
    extrn    recv_copy: near

    extrn    count_in_err: near
    extrn    count_out_err: near


    public    recv
recv:
;called from the recv isr.  All registers have been saved, and ds=cs.
;Upon exit, the interrupt will be acknowledged.
    assume    ds:code

    mov    es,base_addr
    assume    es:ub_seg

recv_3:
    test    epp,PAV
    jne    recv_4
    jmp    recv_2            ;yes.
recv_4:

;checking against epp is a pain actually...
    xor    cx,cx            ;start with zero length
    mov    bl,current_page        ;get the first page.
    xor    bh,bh
    mov    dx,bx            ;remember the first page.
count_pages_1:
    mov    al,page_ram[bx]        ;Get page descriptor
    and    al,RPAGE_BITS        ;Only page offset bits PLEASE
    inc    al            ;Add 1 to offset to make length
    xor    ah,ah
    add    cx,ax            ;Add in current page length

    mov    al,page_ram[bx]        ;Get page descriptor
    inc    bx            ;go to the next page
    cmp    bx,NUM_RPAGES        ;wrap around if necessary.
    jb    count_pages_2
    xor    bx,bx
count_pages_2:

    test    al,80h            ;End page?
    je    count_pages_1        ;yes, go add this one's length.

    mov    current_page,bl

    mov    ax,dx            ;multiply dx by RPAGE_LEN.
    xchg    ah,al
    ror    ax,1
    mov    di,ax
    add    di,offset receive_buf    ;get the starting address.
    add    di,EADDR_LEN+EADDR_LEN    ;skip the ethernet addreses and
                    ;  point to the packet type.
    push    bx
    push    cx
    push    dx

    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:

    call    recv_find        ;look up our type.
    assume    es:nothing
    pop    dx
    pop    cx
    pop    bx

    mov    ax,es            ;is this pointer null?
    or    ax,di
    je    just_discard        ;yes - just free the frame.

    push    cx
    push    di
    push    es

    cmp    dx,bx            ;did we wrap around (first >last?)
    jbe    no_wrap            ;no, just do one move.

;we wrapped around the buffer, so we have to move in two halves.
;move the first part.
    mov    ax,dx            ;multiply dx by RPAGE_LEN.
    xchg    ah,al
    ror    ax,1
    mov    si,ax
    add    si,offset receive_buf    ;get the starting address.

    mov    ax,NUM_RPAGES        ;Compute the number of pages to move.
    sub    ax,dx
    xchg    ah,al            ;convert to pages (*RPAGE_LEN).
    ror    ax,1
    cmp    cx,ax            ;are we moving less than that?
    jbe    no_wrap            ;yes, just move it.
    sub    cx,ax            ;reduce the total count by this count.
    push    cx            ;preserve the second part's count
    mov    cx,ax            ;get the first part's count.

    push    ds
    mov    ds,base_addr
    assume    ds:nothing
    call    movemem
    assume    ds:code
    pop    ds

    pop    cx            ;get back the count

    xor    dx,dx

no_wrap:
    mov    ax,dx            ;multiply dx by 128.
    xchg    ah,al
    ror    ax,1
    mov    si,ax
    add    si,offset receive_buf
    mov    ds,base_addr
    assume    ds:nothing
    call    movemem
    assume    ds:code

    pop    ds
    pop    si
    pop    cx
    call    recv_copy
    push    cs
    pop    ds

just_discard:
    mov    es,base_addr
    assume    es:ub_seg
    mov    al,epp            ;Any more packets left?
    and    al,RPAGE_BITS
    cmp    al,current_page
    je    recv_5
    jmp    recv_3
recv_5:

    cmp    al,tsa_lsb        ;Clearing pav bit (SIDEEFFECT)

recv_2:

;Ack the interrupt by turning bit on and off
    mov    al,current_page        ;Set first free page pointer
    mov    ffp,al
    or    al,NIC_IE        ;set interrupt bit, was off
    mov    ffp,al
recv_1:
    ret


    public    recv_exiting
recv_exiting:
;called from the recv isr after interrupts have been acknowledged.
;Only ds and ax have been saved.
    assume    ds:nothing
    ret


    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


    public    usage_msg
usage_msg    db    "usage: ubnic [options] <packet_int_no> <int_no> <base_addr>",CR,LF,'$'

    public    copyright_msg
copyright_msg    db    "Packet driver for the UB PC/NIC, version ",'0'+(majver / 10),'0'+(majver mod 10),".",'0'+version,CR,LF
        db    '$'

int_no_name    db    "Interrupt number ",'$'
base_addr_name    db    "Memory address ",'$'

    extrn    set_recv_isr: near

;enter with si -> argument string, di -> wword to store.
;if there is no number, don't change the number.
    extrn    get_number: near

;enter with si -> argument string, di -> wword to print.
    extrn    print_number: near

;-> the assigned Ethernet address of the card.
    extrn    rom_address: byte

    public    parse_args
parse_args:
;exit with nc if all went well, cy otherwise.
    mov    di,offset int_no
    call    get_number
    mov    di,offset base_addr
    call    get_number
    clc
    ret


    public    etopen
etopen:
    cli

    cmp    base_addr,-1        ;did they ask for auto-configure?
    jne    no_auto_config

    mov    bx,8000h        ;yes, they *could* address it there.
auto_config_1:
    mov    es,bx
    assume    es:ub_seg
    cmp    word ptr es:eaddr_rom[0],00h + 0ddh * 256
    jne    auto_config_2
    cmp    byte ptr es:eaddr_rom[2],01h
    je    auto_config_3
auto_config_2:
    add    bx,800h            ;move up by 32K
    jnc    auto_config_1        ;go if we didn't overflow.
    sti
    stc                ;say that we couldn't init.
    ret

auto_config_3:
    mov    base_addr,bx        ;remember where we found it.
    mov    base_addr+2,0        ;and nuke the rest of the -1.

no_auto_config:
    mov    es,base_addr
    assume    es:ub_seg

    mov    reset,80h        ;Turn on reset line to tie down NIC
    mov    rmode,0            ;no packets for now
    mov    tmode,0            ;Turn on loopback

    mov    al,epp            ;start ffp at epp - eliminates bogus ....
    and    al,07fh
    mov    current_page,al        ;... packets if we've been started before
    mov    ffp,al            ;Make sure interrupt enable is dead

    cmp    al,tsa_lsb        ;Clearing pav bit (SIDEEFFECT)

    mov    tstatus, 0fh        ;Clear xmit status bits
    mov    tmask,0            ;No xmit intrs
    mov    rmask,0            ;'Packet okay' only?
    mov    rstatus,0ffh        ;Clear receiver status bits

    movseg    ds,es
    mov    di,offset rom_address
    push    ds
    mov    ds,base_addr
    mov    si,offset eaddr_rom
    repmov    EADDR_LEN
    pop    ds

    mov    si,offset rom_address
    mov    cx,EADDR_LEN
    call    set_address

;Since first packet will get sent no matter what we do, let's make it
;something everyone (include me) will ignore
;set length to zero

    mov    tsa_lsb,0ffh        ;Get last 8 bits
    mov    tsa_msb,0fh        ;and top 4 bits

    mov    reset,0            ;Clear reset - expect packet to go
;Wait for packet to go!
etopen_1:
    mov    al,csr
    and    al,TPOK or TXDONE
    cmp    al,TPOK or TXDONE
    jne    etopen_1

    mov    tstatus,0fh        ;clear xmiter status
    mov    tmode,0ah        ;Clear loopbk, set parity enable

    mov    csr,0            ;make sure this interrupt was off first
    mov    csr,PAVIntEn        ;Page frame available interrupt only
    mov    al,current_page        ;Set first free page register ...
    or    al,NIC_IE
    mov    ffp,al            ;... and make sure interrupts enabled

    mov    al,epp            ;get epp again
    test    al,PAV
    je    etopen_2
    cmp    al,tsa_lsb        ;Try clearing pav bit (SIDEEFFECT)
etopen_2:

;enable receiving now
;    1 - accept node id packets, multicasts which match first three
;        bytes of node id, and broadcasts
    mov    rmode,1

;
; Now hook in our interrupt
;
    call    set_recv_isr

    sti

    mov    al, int_no        ; Get board's interrupt vector
    add    al, 8
    cmp    al, 8+8            ; Is it a slave 8259 interrupt?
    jb    set_int_num        ; No.
    add    al, 70h - 8 - 8        ; Map it to the real interrupt.
set_int_num:
    xor    ah, ah            ; Clear high byte
    mov    int_num, ax        ; Set parameter_list int num.

;if all is okay,
    mov    dx,offset end_resident
    clc
    ret
;if we got an error,
    stc
    ret

    public    print_parameters
print_parameters:
;echo our command-line parameters
    mov    di,offset int_no
    mov    dx,offset int_no_name
    call    print_number
    mov    di,offset base_addr
    mov    dx,offset base_addr_name
    call    print_number
    ret

code    ends

    end