; Virtual Ports for the BIOS Interaction
;
-; Copyright (C) 2010 Frank Zoll
+; Copyright (C) 2010 Leo C.
;
; This file is part of avrcpm.
;
; along with avrcpm. If not, see <http://www.gnu.org/licenses/>.
;
; $Id$
-;\r
-\r
-\r
-; ---------------- Defines for the Virtual peripherial interface -------
-
-;The hw is modelled to make writing a CPM BIOS easier.
-;Ports:
-;0 - Con status. Returns 0xFF if the UART has a byte, 0 otherwise.
-;1 - Console input, aka UDR.
-;2 - Console output
-;3 - "UART" status: bit 0=rx, bit 1 = tx
-;4 - "UART" data register, no wait
-;15 - Disk select
-;16,17 - Track select
-;18 - Sector select
-;20 - Write addr l
-;21 - Write addr h
-;22 - Trigger - write to read, to write a sector using the above info;
-; , write to allocated/dirctory/unallocated
-
-;----------------------------------------------- Start of Data Segment
-
- .dseg\r
-\r
-\r
+;
+
+
+;
+; Port Direction Function
+;hex dez
+;-------------------------------------------------------------------------
+;00 0 in - Con status.
+; Returns 0xFF if the UART has a byte, 0 otherwise.
+;01 1 in/out - Console input, aka UDR. / Console Output
+;02 2 out - Console Output (deprecated)
+;03 3 in - "UART" status: bit 0 = rx, bit 1 = tx
+;04 4 in - "UART" data register, no wait
+;
+;0D,0E 13,14 in/out - Set address of Bios Controll Block
+;0F 15 in/out - Disk select
+;10,11 16,17 in/out - Track select
+;12,13 18,19 in/out - Sector select
+;14,15 20,21 in/out - Write addr
+;
+;16 22 out - Trigger disk i/o operations
+; Bit 7 = 1: Read sector
+; Bit 6 = 1: Write sector
+; Bit 5 = 1: BIOS WBOOT
+; Bit 4 = 1: BIOS Home
+; Only one of bits 4..7 may be set.
+; If Write function (bit 6=1):
+; Bits 0..2: 0 - write to allocated
+; 1 - write to directory
+; 2 - write unallocated
+; 3 - write to directory
+;
+;16 22 in - Result of last read/write operation.
+; 0x00 = ok, 0xff = error (--> Bad Sector)
+;
+;40 64-71 in/out - Timer/Clock controll.
+;46
+
+
; ---------------------------------------------- Start of Code Segment
- .cseg\r
-\r
+ .cseg
+vport_tbl:
+ .db 00,1 ;Port 0, length 1
+ .dw conStatus ; in
+ .dw dbgOut ; out
+ .db 01,1
+ .dw uartgetc
+ .dw uartputc
+ .db 02,1 ;Port 2 (old console output)
+ .dw uartgetc ; filler
+ .dw uartputc ; deprecated
+ .db 03,1
+ .dw uartstat
+ .dw vport_out_dummy
+ .db 04,1
+ .dw uartin
+ .dw uartout
+
+ .db 13,9 ; Port 13-21, (lenth 9)
+ .dw dsk_param_rd
+ .dw dsk_param_wr
+ .db 22,1
+ .dw dskErrorRet
+ .dw dskDoIt
+
+ .db TIMERPORT,7
+ .dw clockget
+ .dw clockput
+ .db 0,0 ; Stop mark
+
+;---------------------------------------------------------------------
+
+;Called with port in temp2 and value in temp.
+portWrite:
+ set
+ rjmp vprw_start
+
+;Called with port in temp2. Should return value in temp.
+portRead:
+ clt
+
+vprw_start:
+.if PORT_DEBUG > 1
+ tst temp2
+ brne dvp_1 ;don't debug console status
+ brts dvp_1
+ rjmp conStatus
+dvp_1:
+ printnewline
+ brts dvp_11
+ printstring "Port In: "
+ rjmp dvp_12
+dvp_11:
+ printstring "Port Out: "
+dvp_12:
+ push temp
+ mov temp,temp2
+ rcall printhex
+ pop temp
+.endif
+ ldiw z,vport_tbl*2
+
+vprw_loop:
+ lpm _tmp0,z+
+ lpm temp4,z+ ;length
+ cpi temp4,0
+ breq vprw_exit ;no more ports
+
+ mov temp3,temp2
+ sub temp3,_tmp0 ;base port
+ brcs vprw_next ;port # too high
+ cp temp3,temp4 ;may be in range
+ brcs vprw_found ;
+vprw_next: ;port # not in range, test next block.
+ adiw z,4
+ rjmp vprw_loop
+vprw_found:
+ brtc PC+2
+ adiw z,2
+ lpm _tmp0,z+
+ lpm _tmp1,z+
+ movw z,_tmp0
+
+.if PORT_DEBUG > 1
+ push temp2
+ push temp
+ printstring ", exec: "
+ movw temp,z
+ rcall printhexw
+ printstring ", rel port: "
+ mov temp,temp3
+ rcall printhex
+ pop temp
+ pop temp2
+ printstring ", val: "
+ brts dvp_2
+ icall
+ rcall printhex
+ printstring " "
+ ret
+dvp_2:
+ rcall printhex
+ printstring " "
+ ijmp ; relative port # in temp3
+.else
+ ijmp
+.endif
+
+vprw_exit:
+ ; trap for nonexistent port?
+.if PORT_DEBUG > 1
+ printstring ", not found!"
+.endif
+vport_in_dummy:
+ ldi temp,0xff
+vport_out_dummy:
+ ret
+
+
uartstat:
clr temp
lds temp2,rxcount
uartst_1:
ret
+uartin:
+ clr temp
+ lds temp2,rxcount
+ cpse temp2,_0
+ rjmp uartgetc
+ ret
+
uartout:
lds temp2,txcount
cpi temp2,TXBUFSIZE
uartout_1:
ret
-uartin:
- clr temp
- lds temp2,rxcount
- cpse temp2,_0
- rjmp uartgetc
- ret\r
-\r
+
conStatus:
lds temp,rxcount
cpse temp,_0
ldi temp,0xff
ret
-conInp:
- rjmp uartgetc
dbgOut:
printnewline
rcall printhex
ret
-conOut:
- rjmp uartputc\r
-\r
-;Called with port in temp2. Should return value in temp.
-portRead:
- cpi temp2,0
- breq conStatus
- cpi temp2,1
- breq conInp
- cpi temp2,3
- breq uartstat
- cpi temp2,4
- breq uartin
-
- cpi temp2,15
- breq dskDiskCheck
- cpi temp2,22
- breq dskErrorRet
-
- cpi temp2,TIMER_MSECS
- brlo pr_noclock
- cpi temp2,TIMER_MSECS+6
- brsh pr_noclock
- rjmp clockget
-
-pr_noclock:
- ldi temp,0xFF
- ret
-
-;Called with port in temp2 and value in temp.
-portWrite:
- cpi temp2,0
- breq dbgOut
- cpi temp2,2
- breq conOut
- cpi temp2,4
- breq uartout
-
- cpi temp2,15
- breq dskDiskSel
- cpi temp2,16
- breq dskTrackSel_l
- cpi temp2,17
- breq dskTrackSel_h
- cpi temp2,18
- breq dskSecSel
- cpi temp2,20
- breq dskDmaL
- cpi temp2,21
- breq dskDmaH
-
- cpi temp2,22
- breq dskDoIt
-
- cpi temp2,TIMERPORT
- brlo pw_noclock
- cpi temp2,TIMER_MSECS+6
- brsh pw_noclock
- rjmp clockput
-
-pw_noclock:
- ret\r
-\r
-
-\r
;---------------------------------------------------------------------
+; vim:set ts=8 noet nowrap
+
projects / avrcpm.git / blobdiff