QRZ! Ham Radio 9

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/ QRZ! Ham Radio 9 / QRZ Ham Radio Callsign Database - Volume 9.iso / pc / files / pbbs / iosc51.arc / BR2BIOS.ASM < prev

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Assembly Source File | 1996-06-24 | 17.4 KB | 502 lines

PAGE 60,132 TITLE BR2BIOS - Serial interface for COM2 ;Interupt driven RS232 serial port routines. ; these routines replace the BIOS rs232 calls with a version that has ; interupt driven character receive, and can thus operate at considerably ; higher speeds than the standard bios calls (int 14h). ; Added break function (7). ; Set up the works everything SEGMENT PUBLIC ASSUME CS: everything ; These assumptions are for the ASSUME DS: everything ; assembler's benefit. The code ASSUME ES: nothing ; jerks things around as it pleases ASSUME SS: nothing ; ; Program start and buffer declares ORG 100H foo: JMP start ; Entry point ORG 0 ; Back up so we can use this all as ; buffer space ; Area where things are declared include constbios.asm dummy: ; Dummy labels to provide a structure buffer DB buffer_size dup(?) ; Buffer (1 per com card) buffer_e: ; End of buffer comnumber DB ? ; Comm number - 1 flags DB ? ; Flag byte last_rs DB ? ; Last receive status hiv DB ? ; Hardware interrupt vector int_mask DB ? ; Mask for 8259 baseaddr DW ? ; Base port address count DW ? ; # of chars in buffer buffer_in DW ? ; Buffer in pointer buffer_out DW ? ; Buffer out pointer dummy_end: ORG dummy ; Back up over this ; These are the things to work with DB buffer_size dup(?) ; Buffer (1 per com card) DB 1 ; Com number DB 0 ; Flags DB 0 ; Last receive status DB 0BH ; Hardware interrupt vector DB 0F7H ; Mask DW 02F8H ; Base port address DW 0 ; # of chars in buffer DW ? ; Buffer in pointer DW ? ; Buffer out pointer comend: ; Marker for last com port ; Static variables old_bios_vector DW ? ; Save previous interrupt vector DW ? ; divisor_table LABEL WORD ; DW 1047 ; 110 DW 768 ; 150 DW 384 ; 300 DW 192 ; 600 DW 96 ; 1200 DW 48 ; 2400 DW 24 ; 4800 DW 12 ; 9600 ; Our BIOS handler rsint: ASSUME DS: NOTHING ; Don't use DS ASSUME ES: NOTHING ; Don't use ES ASSUME SS: NOTHING ; Don't use SS ; Not disabled please STI ; See if this is our vector? PUSH BP ; Save BP over our loop XOR BP,BP CMP DL,CS:comnumber[BP] ; Is this our port? JE rsint_ours ; Yes... ; Not us.. Pop things out and call regular handler POP BP ; Pop BP JMP CS:DWORD PTR old_bios_vector ; BP now contains the pointer to the com block... See what ; the user has requested and we may or may not do it....... rsint_ours: PUSH DX ; We need the DX register PUSH CX ; We need the CX register PUSH BX ; We need the BX register MOV CX,baseaddr[BP] ; Get base address for chip OR AH,AH ; Initialize JE rsint_init ; Yes... DEC AH ; 1 = Send character JZ rsint_send DEC AH ; 2 = Receive character JZ rsint_recv_jmp DEC AH ; 3 = Status request JZ rsint_status_jmp DEC AH ; 4 = Inquiry JZ rsint_inquiry_jmp dec ah dec ah dec ah jmp rsint_break_jmp ; 7 = send break. jmp rsint_exit ; Nope.. rsint_recv_jmp: JMP rsint_recv rsint_status_jmp: JMP rsint_status rsint_inquiry_jmp: JMP rsint_inquiry rsint_break_jmp: jmp rsint_break ; Interrupt exit rsint_exit: POP BX ; Restore registers POP CX POP DX POP BP IRET ; and leave ; Init.. rsint_init: MOV AH,AL ; Save the parms for later MOV BL,AH ; Look up the baud rate MOV CL,4 ; parameter ROL BL,CL AND BX,0EH MOV BX,divisor_table[BX] MOV CX,baseaddr[BP] ; Get base address for chip MOV DX,CX ; Address of LCR ADD DX,lcr_8250 MOV AL,10000000B ; Enable access to divisor OUT DX,AL MOV DX,CX ; Address of lower divisior half ADD DX,dll_8250 MOV AL,BL ; Put lower half OUT DX,AL MOV DX,CX ; Address of upper divisior half ADD DX,dlm_8250 MOV AL,BH ; Put upper half OUT DX,AL MOV AL,AH ; Get parms back AND AL,01FH ; Throw away baud rate MOV DX,CX ; Address of LCR ADD DX,lcr_8250 OUT DX,AL ; Output the parms MOV DX,CX ; Compute port address for the MCR ADD DX,mcr_8250 ; mov AL,00001011B ; Raise DTR, RTS & OUT2 ; OUT2 turns on interrupts OUT DX,AL ; JMP rsint_status ; Now just status please ; Send a character rsint_send: MOV AH,AL ; Save the character to send rsint_send_loop: ; Loop here until we can send MOV DX,CX ; Compute port address for the MSR ADD DX,msr_8250 ; and then IN AL,DX ; get it into AX AND AL,10H ; CTS jz rsint_send_loop MOV DX,CX ; Compute port address for the LSR ADD DX,lsr_8250 ; and then IN AL,DX ; get itinto AX and AL,20H ; THR empty? JZ rsint_send_loop ; No.. Loop back MOV AL,AH ; Get ready to out character MOV DX,CX ; Compute port address for the THR ; ADD DX,thr_8250 ; and then OUT DX,AL ; out the character JMP rsint_status ; Do a status ; Receive a character rsint_recv: MOV BX,buffer_out[BP] ; Get buffer output pointer rsint_recv_loop: CMP count[BP],0 ; See in anything in buffer JE rsint_recv_loop ; Wait for it rsint_get_char: MOV AL,CS:[BX] ; Get character from buffer PUSH AX ; Save char INC BX ; Bump pointer DEC count[BP] ; Dec char count MOV DX,OFFSET buffer_e ; Compute end of buffer ADD DX,BP CMP BX,DX ; Have we wrapped the buffer? JL test_handshake ; No.. All done MOV BX,OFFSET buffer ; Yes.. Reset pointer ADD BX,BP test_handshake: cmp count[BP],80H jnb test_full mov ah,flags[BP] test ah,1 jz test_full roll_hands: mov DX,CX add DX,mcr_8250 in AL,DX or AL,00001011B ; Raise DTR, RTS & OUT2 out DX,AL and AH,0FEH mov flags[BP],AH test_full: POP AX ; Restore Char MOV buffer_out[BP],BX ; Save pointer MOV AH,last_rs[BP] ; Get last LSR from receive AND AH,11111110B ; Remove data ready bit CMP count[BP],0 ; Anything left in buffer? JE short_exit ; Nope so leave OR AH,00000001B ; Turn on data ready short_exit: JMP rsint_exit ; and go leave ; Status.. rsint_status: MOV DX,CX ; Compute port address for the LSR ADD DX,lsr_8250 ; and then IN AL,DX ; get it AND AL,11111110B ; Remove data ready bit CMP count[BP],0 ; Anything left in buffer? JE rsint_status_nodr ; Nope so leave OR AL,00000001B ; Turn on data ready rsint_status_nodr: MOV AH,AL ; Save LSR MOV DX,CX ; Compute port address for the MSR ADD DX,msr_8250 ; and then IN AL,DX ; get it JMP rsint_exit ; All done ; Inquiry ; (Return AA55H in AX - Just an identification scheme to tell ; if this silly driver has been loaded) rsint_inquiry: MOV AX,0AA55H JMP rsint_exit ; and go leave ;send break rsint_break: mov dx,cx add dx,lcr_8250 in al,dx mov bl,al mov al,40h out dx,al mov cx,0 bkwait: loop bkwait mov al,bl out dx,al jmp rsint_exit ; 8250 interrupt handler serint_8250: PUSH BP PUSH DX PUSH AX PUSH CX ; Save some registers PUSH DI ; xor bp,bp MOV CX,baseaddr[BP] ; Get base address for chip MOV DX,CX ; Get the IIR ADD DX,iir_8250 ; IN AL,DX ; TEST AL,00000001B ; Interrupt pending? JZ service JMP serint_8250_exit ; No leave... service: MOV DX,CX ; Get the LSR ADD DX,lsr_8250 IN AL,DX MOV last_rs[BP],AL ; And tuck it away MOV DX,CX ; Get the RBR ; ADD DX,rbr_8250 IN AL,DX MOV DI,buffer_in[BP] ; Get the buffer pointer MOV CS:[DI],AL ; Save the character INC DI ; Bump pointer and handle wrap MOV AX,OFFSET buffer_e ADD AX,BP CMP DI,AX JL serint_8250_nowrap MOV DI,OFFSET buffer ADD DI,BP serint_8250_nowrap: cmp count[BP],buffer_full jb hand_done mov DX,CX add DX,mcr_8250 in al,DX and AL,11111100B ; Drop DTR & RTS out DX,AL mov ah,flags[BP] or AH,1 mov flags[BP],AH hand_done: CMP DI,buffer_out[BP] ; Overflow of buffer? JNE serint_8250_noover OR last_rs[BP],02H ; Overrun indicate JMP SHORT serint_8250_exit ; Don't save the updated pointer serint_8250_noover: MOV buffer_in[BP],DI ; Save the updated pointer inc count[BP] ; inc char count serint_8250_exit: MOV AL,020H ; Tell 8259 we are done OUT pic_cmd_port,AL POP DI ; Restore registers POP CX POP AX POP DX POP BP IRET ; Exit program_end: ; Main line to initialize. ASSUME DS: everything ; Constants only needed by initialization P3F8 DB 0 ;1 IF CARD AT 3F8 P2F8 DB 0 ;1 IF CARD AT 2F8 HELLO DB CR,LF DB 'COM2BIOS Driver v1.5',CR,LF DB 'Dec 18, 1986 ' DB CR,LF,'$' BYE DB CR,LF DB 'Driver Installed OK!' DB CR,LF,'$' LOADED DB CR,LF DB 'COM2BIOS already loaded!' DB CR,LF,'$' COM1F DB CR,LF DB 'COM1: board found at 03F8',CR,LF DB '$' COM2F DB CR,LF DB 'COM2: board found at 02F8',CR,LF DB '$' NOCOM DB CR,LF DB 'COM2: board not found.' DB CR,LF DB 'Driver NOT installed!',CR,LF DB '$' ; INITIALIZE ROUTINE start: MOV AX,CS ; Point DS in the right place MOV DS,AX CALL SINON ;PRINT SIGN ON MOV DX,1 ;Check to see if support already loaded MOV AH,4 INT 14H CMP AX,0AA55H JZ EXIT ;Must be loaded CALL CNFIG ;CHECK CONFIGURATION OR AX,AX JNZ EREXIT ;JMP IF ERRORS CALL init_vectors ;SET INTERRUPT VECTORS CALL SINOFF ;PRINT SIGN OFF MOV AL,0 ;set exit code MOV DX,OFFSET program_end MOV CL,4 SHR DX,CL INC DX MOV AH,31H INT 21H ; Terminate but stay resident EREXIT: MOV AL,1 ;set exit code = Error MOV AH,4CH INT 21H ; Terminate and return EXIT: LEA DX,LOADED MOV AH,9 INT 21H MOV AL,0 ;set exit code = Ok MOV AH,4CH INT 21H ; Terminate and return ld_ rea'$n oddrEDW tJMP Idreno rsin,CXlarp r ADD DDX ; DG_loopP],0hand_dDW nter;ask Dohanst_hndlOTHPU eSUM 19THIOTH≡ hip C AAAAAAAAAAAAAAA; .. 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