mirror of
https://github.com/cc65/cc65.git
synced 2025-01-10 19:29:45 +00:00
521 lines
18 KiB
ArmAsm
521 lines
18 KiB
ArmAsm
;
|
|
; Serial driver for the Apple II Super Serial Card.
|
|
;
|
|
; Oliver Schmidt, 21.04.2005
|
|
;
|
|
; The driver is based on the cc65 rs232 module, which in turn is based on
|
|
; Craig Bruce device driver for the Switftlink/Turbo-232.
|
|
;
|
|
; SwiftLink/Turbo-232 v0.90 device driver, by Craig Bruce, 14-Apr-1998.
|
|
;
|
|
; This software is Public Domain. It is in Buddy assembler format.
|
|
;
|
|
; This device driver uses the SwiftLink RS-232 Serial Cartridge, available from
|
|
; Creative Micro Designs, Inc, and also supports the extensions of the Turbo232
|
|
; Serial Cartridge. Both devices are based on the 6551 ACIA chip. It also
|
|
; supports the "hacked" SwiftLink with a 1.8432 MHz crystal.
|
|
;
|
|
; The code assumes that the kernal + I/O are in context. On the C128, call
|
|
; it from Bank 15. On the C64, don't flip out the Kernal unless a suitable
|
|
; NMI catcher is put into the RAM under then Kernal. For the SuperCPU, the
|
|
; interrupt handling assumes that the 65816 is in 6502-emulation mode.
|
|
;
|
|
|
|
.include "zeropage.inc"
|
|
.include "ser-kernel.inc"
|
|
.include "ser-error.inc"
|
|
|
|
.macpack module
|
|
.macpack cpu
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Header. Includes jump table
|
|
|
|
.ifdef __APPLE2ENH__
|
|
module_header _a2e_ssc_ser
|
|
.else
|
|
module_header _a2_ssc_ser
|
|
.endif
|
|
|
|
; Driver signature
|
|
.byte $73, $65, $72 ; "ser"
|
|
.byte SER_API_VERSION ; Serial API version number
|
|
|
|
; Library reference
|
|
.addr $0000
|
|
|
|
; Jump table
|
|
.addr SER_INSTALL
|
|
.addr SER_UNINSTALL
|
|
.addr SER_OPEN
|
|
.addr SER_CLOSE
|
|
.addr SER_GET
|
|
.addr SER_PUT
|
|
.addr SER_STATUS
|
|
.addr SER_IOCTL
|
|
.addr SER_IRQ
|
|
|
|
;----------------------------------------------------------------------------
|
|
; I/O definitions
|
|
|
|
.if (.cpu .bitand CPU_ISET_65C02)
|
|
ACIA := $C088
|
|
.else
|
|
Offset = $8F ; Move 6502 false read out of I/O to page $BF
|
|
ACIA := $C088-Offset
|
|
.endif
|
|
|
|
ACIA_DATA := ACIA+0 ; Data register
|
|
ACIA_STATUS := ACIA+1 ; Status register
|
|
ACIA_CMD := ACIA+2 ; Command register
|
|
ACIA_CTRL := ACIA+3 ; Control register
|
|
|
|
SLTROMSEL := $C02D ; For Apple IIgs slot verification
|
|
|
|
;----------------------------------------------------------------------------
|
|
; Global variables
|
|
|
|
.bss
|
|
|
|
RecvHead: .res 1 ; Head of receive buffer
|
|
RecvTail: .res 1 ; Tail of receive buffer
|
|
RecvFreeCnt: .res 1 ; Number of free bytes in receive buffer
|
|
SendHead: .res 1 ; Head of send buffer
|
|
SendTail: .res 1 ; Tail of send buffer
|
|
SendFreeCnt: .res 1 ; Number of free bytes in send buffer
|
|
|
|
Stopped: .res 1 ; Flow-stopped flag
|
|
RtsOff: .res 1 ; Cached value of command register with
|
|
; flow stopped
|
|
HSType: .res 1 ; Flow-control type
|
|
|
|
RecvBuf: .res 256 ; Receive buffer: 256 bytes
|
|
SendBuf: .res 256 ; Send buffer: 256 bytes
|
|
|
|
Index: .res 1 ; I/O register index
|
|
|
|
.data
|
|
|
|
Slot: .byte $02 ; Default to SSC in slot 2
|
|
|
|
.rodata
|
|
|
|
BaudTable: ; Table used to translate RS232 baudrate param
|
|
; into control register value
|
|
; bit7 = 1 means setting is invalid
|
|
.byte $FF ; SER_BAUD_45_5
|
|
.byte $01 ; SER_BAUD_50
|
|
.byte $02 ; SER_BAUD_75
|
|
.byte $03 ; SER_BAUD_110
|
|
.byte $04 ; SER_BAUD_134_5
|
|
.byte $05 ; SER_BAUD_150
|
|
.byte $06 ; SER_BAUD_300
|
|
.byte $07 ; SER_BAUD_600
|
|
.byte $08 ; SER_BAUD_1200
|
|
.byte $09 ; SER_BAUD_1800
|
|
.byte $0A ; SER_BAUD_2400
|
|
.byte $0B ; SER_BAUD_3600
|
|
.byte $0C ; SER_BAUD_4800
|
|
.byte $0D ; SER_BAUD_7200
|
|
.byte $0E ; SER_BAUD_9600
|
|
.byte $0F ; SER_BAUD_19200
|
|
.byte $FF ; SER_BAUD_38400
|
|
.byte $FF ; SER_BAUD_57600
|
|
.byte $00 ; SER_BAUD_115200
|
|
.byte $FF ; SER_BAUD_230400
|
|
|
|
BitTable: ; Table used to translate RS232 databits param
|
|
; into control register value
|
|
.byte $60 ; SER_BITS_5
|
|
.byte $40 ; SER_BITS_6
|
|
.byte $20 ; SER_BITS_7
|
|
.byte $00 ; SER_BITS_8
|
|
|
|
StopTable: ; Table used to translate RS232 stopbits param
|
|
; into control register value
|
|
.byte $00 ; SER_STOP_1
|
|
.byte $80 ; SER_STOP_2
|
|
|
|
ParityTable: ; Table used to translate RS232 parity param
|
|
; into command register value
|
|
.byte $00 ; SER_PAR_NONE
|
|
.byte $20 ; SER_PAR_ODD
|
|
.byte $60 ; SER_PAR_EVEN
|
|
.byte $A0 ; SER_PAR_MARK
|
|
.byte $E0 ; SER_PAR_SPACE
|
|
|
|
IdOfsTable: ; Table of bytes positions, used to check four
|
|
; specific bytes on the slot's firmware to make
|
|
; sure this is a serial card.
|
|
.byte $05 ; Pascal 1.0 ID byte
|
|
.byte $07 ; Pascal 1.0 ID byte
|
|
.byte $0B ; Pascal 1.1 generic signature byte
|
|
.byte $0C ; Device signature byte
|
|
|
|
IdValTable: ; Table of expected values for the four checked
|
|
; bytes
|
|
.byte $38 ; ID Byte 0 (from Pascal 1.0), fixed
|
|
.byte $18 ; ID Byte 1 (from Pascal 1.0), fixed
|
|
.byte $01 ; Generic signature for Pascal 1.1, fixed
|
|
.byte $31 ; Device signature byte (serial or
|
|
; parallel I/O card type 1)
|
|
|
|
IdTableLen = * - IdValTable
|
|
|
|
.code
|
|
|
|
;----------------------------------------------------------------------------
|
|
; SER_INSTALL: Is called after the driver is loaded into memory. If possible,
|
|
; check if the hardware is present. Must return an SER_ERR_xx code in a/x.
|
|
;
|
|
; Since we don't have to manage the IRQ vector on the Apple II, this is
|
|
; actually the same as:
|
|
;
|
|
; SER_UNINSTALL: Is called before the driver is removed from memory.
|
|
; No return code required (the driver is removed from memory on return).
|
|
;
|
|
; and:
|
|
;
|
|
; SER_CLOSE: Close the port and disable interrupts. Called without parameters.
|
|
; Must return an SER_ERR_xx code in a/x.
|
|
|
|
SER_INSTALL:
|
|
SER_UNINSTALL:
|
|
SER_CLOSE:
|
|
ldx Index ; Check for open port
|
|
beq :+
|
|
|
|
lda #%00001010 ; Deactivate DTR and disable 6551 interrupts
|
|
sta ACIA_CMD,x
|
|
|
|
: lda #SER_ERR_OK ; Done, return an error code
|
|
.assert SER_ERR_OK = 0, error
|
|
tax
|
|
stx Index ; Mark port as closed
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; SER_OPEN: A pointer to a ser_params structure is passed in ptr1.
|
|
; Must return an SER_ERR_xx code in a/x.
|
|
; Note: Hardware checks are done in SER_OPEN instead of SER_INSTALL,
|
|
; because they depend on the selected slot, and we can't select the slot
|
|
; before SER_INSTALL.
|
|
|
|
SER_OPEN:
|
|
; Check if this is a IIgs (Apple II Miscellaneous TechNote #7,
|
|
; Apple II Family Identification)
|
|
sec
|
|
bit $C082
|
|
jsr $FE1F
|
|
bit $C080
|
|
|
|
bcs NotIIgs
|
|
|
|
; We're on a IIgs. For every slot N, either bit N of $C02D is
|
|
; 0 for the internal ROM, or 1 for "Your Card". Let's make sure
|
|
; that slot N's bit is set to 1, otherwise, that can't be an SSC.
|
|
|
|
ldy Slot
|
|
lda SLTROMSEL
|
|
: lsr
|
|
dey
|
|
bpl :- ; Shift until slot's bit ends in carry
|
|
bcc NoDev
|
|
|
|
NotIIgs:ldx #<$C000
|
|
stx ptr2
|
|
lda #>$C000
|
|
ora Slot
|
|
sta ptr2+1
|
|
|
|
: ldy IdOfsTable,x ; Check Pascal 1.1 Firmware Protocol ID bytes
|
|
lda IdValTable,x
|
|
cmp (ptr2),y
|
|
bne NoDev
|
|
inx
|
|
cpx #IdTableLen
|
|
bcc :-
|
|
|
|
lda Slot ; Convert slot to I/O register index
|
|
asl
|
|
asl
|
|
asl
|
|
asl
|
|
.if .not (.cpu .bitand CPU_ISET_65C02)
|
|
adc #Offset ; Assume carry to be clear
|
|
.endif
|
|
tax
|
|
|
|
; Check that this works like an ACIA 6551 is expected to work
|
|
|
|
lda ACIA_STATUS,x ; Save current values in what we expect to be
|
|
sta tmp1 ; the ACIA status register
|
|
lda ACIA_CMD,x ; and command register. So we can restore them
|
|
sta tmp2 ; if this isn't a 6551.
|
|
|
|
ldy #%00000010 ; Disable TX/RX, disable IRQ
|
|
: tya
|
|
sta ACIA_CMD,x
|
|
cmp ACIA_CMD,x ; Verify what we stored is there
|
|
bne NotAcia
|
|
iny ; Enable TX/RX, disable IRQ
|
|
cpy #%00000100
|
|
bne :-
|
|
sta ACIA_STATUS,x ; Reset ACIA
|
|
lda ACIA_CMD,x ; Check that RX/TX is disabled
|
|
lsr
|
|
bcc AciaOK
|
|
|
|
NotAcia:lda tmp2 ; Restore original values
|
|
sta ACIA_CMD,x
|
|
lda tmp1
|
|
sta ACIA_STATUS,x
|
|
|
|
NoDev: lda #SER_ERR_NO_DEVICE
|
|
bne Out
|
|
|
|
; Check if the handshake setting is valid
|
|
AciaOK: ldy #SER_PARAMS::HANDSHAKE
|
|
lda (ptr1),y
|
|
cmp #SER_HS_SW ; Not supported
|
|
bne HandshakeOK
|
|
|
|
lda #SER_ERR_INIT_FAILED
|
|
bne Out
|
|
|
|
HandshakeOK:
|
|
sta HSType ; Store flow control type
|
|
|
|
ldy #$00 ; Initialize buffers
|
|
sty Stopped
|
|
sty RecvHead
|
|
sty RecvTail
|
|
sty SendHead
|
|
sty SendTail
|
|
dey ; Y = 255
|
|
sty RecvFreeCnt
|
|
sty SendFreeCnt
|
|
|
|
; Set the value for the control register, which contains stop bits,
|
|
; word length and the baud rate.
|
|
ldy #SER_PARAMS::BAUDRATE
|
|
lda (ptr1),y ; Baudrate index
|
|
tay
|
|
lda BaudTable,y ; Get 6551 value
|
|
sta tmp2 ; Backup for IRQ setting
|
|
bpl BaudOK ; Check that baudrate is supported
|
|
|
|
lda #SER_ERR_BAUD_UNAVAIL
|
|
bne Out
|
|
|
|
BaudOK: sta tmp1
|
|
ldy #SER_PARAMS::DATABITS
|
|
lda (ptr1),y ; Databits index
|
|
tay
|
|
lda BitTable,y ; Get 6551 value
|
|
ora tmp1
|
|
sta tmp1
|
|
|
|
ldy #SER_PARAMS::STOPBITS
|
|
lda (ptr1),y ; Stopbits index
|
|
tay
|
|
lda StopTable,y ; Get 6551 value
|
|
ora tmp1
|
|
ora #%00010000 ; Set receiver clock source = baudrate
|
|
sta ACIA_CTRL,x
|
|
|
|
; Set the value for the command register. We remember the base value
|
|
; in RtsOff, since we will have to manipulate ACIA_CMD often.
|
|
ldy #SER_PARAMS::PARITY
|
|
lda (ptr1),y ; Parity index
|
|
tay
|
|
lda ParityTable,y ; Get 6551 value
|
|
|
|
ora #%00000001 ; Set DTR active
|
|
sta RtsOff ; Store value to easily handle flow control later
|
|
|
|
ora #%00001010 ; Disable interrupts and set RTS low
|
|
|
|
ldy tmp2 ; Don't enable IRQs if 115200bps
|
|
beq :+
|
|
and #%11111101 ; Enable receive IRQs
|
|
: sta ACIA_CMD,x
|
|
|
|
; Done
|
|
stx Index ; Mark port as open
|
|
lda #SER_ERR_OK
|
|
Out:
|
|
ldx #$00 ; Promote char return value
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; SER_GET: Will fetch a character from the receive buffer and store it into the
|
|
; variable pointed to by ptr1. If no data is available, SER_ERR_NO_DATA is
|
|
; returned.
|
|
|
|
SER_GET:
|
|
ldx Index
|
|
|
|
lda RecvFreeCnt ; Check for buffer empty
|
|
cmp #$FF
|
|
bne :+
|
|
lda #SER_ERR_NO_DATA
|
|
ldx #$00 ; Promote char return value
|
|
rts
|
|
|
|
: ldy Stopped ; Check for flow stopped
|
|
beq :+
|
|
cmp #63 ; Enough free?
|
|
bcc :+
|
|
.if (.cpu .bitand CPU_ISET_65C02)
|
|
stz Stopped ; Release flow control
|
|
.else
|
|
lda #$00
|
|
sta Stopped
|
|
.endif
|
|
lda RtsOff
|
|
ora #%00001000
|
|
sta ACIA_CMD,x
|
|
|
|
: ldy RecvHead ; Get byte from buffer
|
|
lda RecvBuf,y
|
|
inc RecvHead
|
|
inc RecvFreeCnt
|
|
ldx #$00
|
|
.if (.cpu .bitand CPU_ISET_65C02)
|
|
sta (ptr1) ; Store it for caller
|
|
.else
|
|
sta (ptr1,x)
|
|
.endif
|
|
txa ; Return code = 0
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; SER_PUT: Output character in A.
|
|
; Must return an SER_ERR_xx code in a/x.
|
|
|
|
SER_PUT:
|
|
ldx Index
|
|
|
|
ldy SendFreeCnt ; Anything to send first?
|
|
cpy #$FF ; No
|
|
beq :+
|
|
pha
|
|
lda #$00 ; TryHard = false
|
|
jsr TryToSend ; Try to flush send buffer
|
|
pla
|
|
|
|
ldy SendFreeCnt ; Reload SendFreeCnt after TryToSend
|
|
bne :+
|
|
lda #SER_ERR_OVERFLOW
|
|
ldx #$00 ; Promote char return value
|
|
rts
|
|
|
|
: ldy SendTail ; Put byte into send buffer
|
|
sta SendBuf,y
|
|
inc SendTail
|
|
dec SendFreeCnt
|
|
lda #$FF ; TryHard = true
|
|
jsr TryToSend ; Flush send buffer
|
|
lda #SER_ERR_OK
|
|
.assert SER_ERR_OK = 0, error
|
|
tax
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; SER_STATUS: Return the status in the variable pointed to by ptr1.
|
|
; Must return an SER_ERR_xx code in a/x.
|
|
|
|
SER_STATUS:
|
|
ldx Index
|
|
lda ACIA_STATUS,x
|
|
ldx #$00
|
|
sta (ptr1,x)
|
|
.assert SER_ERR_OK = 0, error
|
|
txa
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; SER_IOCTL: Driver defined entry point. The wrapper will pass a pointer to ioctl
|
|
; specific data in ptr1, and the ioctl code in A.
|
|
; The ioctl data is the slot number to open.
|
|
; Must return an SER_ERR_xx code in a/x.
|
|
|
|
SER_IOCTL:
|
|
ora ptr1+1 ; Check data msb and code to be 0
|
|
bne :+
|
|
|
|
ldx ptr1 ; Check data lsb to be [1..7]
|
|
beq :+
|
|
cpx #7+1
|
|
bcs :+
|
|
|
|
stx Slot ; Store slot
|
|
.assert SER_ERR_OK = 0, error
|
|
tax
|
|
rts
|
|
|
|
: lda #SER_ERR_INV_IOCTL
|
|
ldx #$00 ; Promote char return value
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; SER_IRQ: Called from the builtin runtime IRQ handler as a subroutine. All
|
|
; registers are already saved, no parameters are passed, but the carry flag
|
|
; is clear on entry. The routine must return with carry set if the interrupt
|
|
; was handled, otherwise with carry clear.
|
|
|
|
SER_IRQ:
|
|
ldx Index ; Check for open port
|
|
beq Done
|
|
lda ACIA_STATUS,x ; Check ACIA status for receive interrupt
|
|
and #$08
|
|
beq Done ; Jump if no ACIA interrupt
|
|
lda ACIA_DATA,x ; Get byte from ACIA
|
|
ldx RecvFreeCnt ; Check if we have free space left
|
|
beq Flow ; Jump if no space in receive buffer
|
|
ldy RecvTail ; Load buffer pointer
|
|
sta RecvBuf,y ; Store received byte in buffer
|
|
inc RecvTail ; Increment buffer pointer
|
|
dec RecvFreeCnt ; Decrement free space counter
|
|
cpx #33 ; Check for buffer space low
|
|
bcc Flow ; Assert flow control if buffer space low
|
|
rts ; Interrupt handled (carry already set)
|
|
|
|
Flow: lda HSType ; Don't touch if no flow control
|
|
beq IRQDone
|
|
|
|
ldx Index ; Assert flow control if buffer space too low
|
|
lda RtsOff
|
|
sta ACIA_CMD,x
|
|
sta Stopped
|
|
IRQDone:sec ; Interrupt handled
|
|
Done: rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; Try to send a byte. Internal routine. A = TryHard
|
|
|
|
TryToSend:
|
|
sta tmp1 ; Remember tryHard flag
|
|
NextByte:
|
|
lda SendFreeCnt ; Is there anything to send? This can happen if
|
|
cmp #$FF ; we got interrupted by RX while sending, and
|
|
beq Quit ; flow control was asserted.
|
|
|
|
Again: lda Stopped ; Is flow stopped?
|
|
bne Quit ; Yes, Bail out
|
|
|
|
lda ACIA_STATUS,x ; Check that ACIA is ready to send
|
|
and #$10
|
|
bne Send ; It is!
|
|
bit tmp1 ; Keep trying if must try hard
|
|
bmi Again
|
|
Quit: rts
|
|
|
|
Send: ldy SendHead ; Get first byte to send
|
|
lda SendBuf,y
|
|
sta ACIA_DATA,x ; Send it
|
|
inc SendHead
|
|
inc SendFreeCnt
|
|
bne NextByte ; And try next one
|