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[/] [System09/] [trunk/] [src/] [Noice/] [MON6809.ASM] - Rev 203
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* 6809 Debug monitor for use with NOICE09
*
* Copyright (c) 1992-2006 by John Hartman
*
* Modification History:
* 14-Jun-93 JLH release version
* 24-Aug-93 JLH bad constant for COMBUF length compare
* 25-Feb-98 JLH assemble with either Motorola or Dunfield
* 1-May-06 JLH slight cleanup
* 4-Jul-06 JEK Modified for System09 ACIA at $E000/$E001
* 2K monitor RAM at $F000 - $F7FF
* Allocated 1536 bytes ($600) for user stack.
* disables watchdog timer
*
*============================================================================
*
* To customize for a given target, you must change code in the
* hardware equates, the string TSTG, and the routines RESET and REWDT.
* You may or may not need to change GETCHAR, PUTCHAR, depending on
* how peculiar your UART is.
*
* This file has been assembled with the Motorola Freeware assembler
* available from the Motorola Freeware BBS and elsewhere.
* BUT: you must first "comment out" the conditionals as required,
* because the Motorola assemblers do not have any IFEQ/ELSE/ENDIF
*
* This file may also be assembled with the Dunfield assembler
*
* To add mapped memory support:
* 1) Define map port MAPREG here
* 2) Define or import map port RAM image MAPIMG here if MAPREG is
* write only. (The application code must update MAPIMG before
* outputing to MAPREG)
* 3) Search for and modify MAPREG, MAPIMG, and REG_PAGE usage below
* 4) In TSTG below edit "LOW AND HIGH LIMIT OF MAPPED MEM"
* to appropriate range (typically 4000H to 07FFFH for two-bit MMU)
*
*============================================================================
*
* I/O equates for Heng's ROM emulator (set true if used)
***ROMEM SET 1
*
*============================================================================
* HARDWARE PLATFORM CUSTOMIZATIONS
*
*RAM_START EQU $D800 START OF MONITOR RAM
RAM_START EQU $F000 START OF MONITOR RAM
ROM_START EQU $FC00 START OF MONITOR CODE
HARD_VECT EQU $FFF0 START OF HARDWARE VECTORS
*============================================================================
* Equates for memory mapped 16450 serial port on Heng's ROM emulator board
*;* IFEQ ROMEM,1
*
*S16450 equ $A000 base of 16450 UART
*RXR equ 0 Receiver buffer register
*TXR equ 0 Transmitter buffer register
*IER equ 1 Interrupt enable register
*LCR equ 3 Line control register
*MCR equ 4 Modem control register
*DTR equ 1 Bit equate used to control status LED
*LSR equ 5 Line status register
*
* Define monitor serial port
*SER_STATUS EQU S16450+LSR
*SER_RXDATA EQU S16450+RXR
*SER_TXDATA EQU S16450+TXR
*RXRDY EQU $01 BIT MASK FOR RX BUFFER FULL
*TXRDY EQU $20 BIT MASK FOR TX BUFFER EMPTY
*;* ELSE
*
* Put you UART equates here
SER_STATUS EQU $E000
SER_RXDATA EQU $E001
SER_TXDATA EQU $E001
RXRDY EQU $01
TXRDY EQU $02
*
*;* ENDIF
*
* Watchdog timer (if any) See REWDT for use
*WDT EQU $207
*
* Condition code bits
C EQU 1
I EQU 10H
F EQU 40H
E EQU 80H
*
*============================================================================
* RAM definitions:
ORG RAM_START
*
* RAM interrupt vectors (first in SEG for easy addressing, else move to
* their own SEG)
NVEC EQU 8 number of vectors
RAMVEC RMB 2*NVEC
*
* Initial user stack
* (Size and location is user option)
* RMB 64
RMB $600
INITSTACK
*
* Monitor stack
* (Calculated use is at most 7 bytes. Leave plenty of spare)
RMB 16
MONSTACK
*
* Target registers: order must match that in TRGHC11.C
TASK_REGS
REG_STATE RMB 1
REG_PAGE RMB 1
REG_SP RMB 2
REG_U RMB 2
REG_Y RMB 2
REG_X RMB 2
REG_B RMB 1 B BEFORE A, SO D IS LEAST SIG. FIRST
REG_A RMB 1
REG_DP RMB 1
REG_CC RMB 1
REG_PC RMB 2
TASK_REG_SZ EQU *-TASK_REGS
*
* Communications buffer
* (Must be at least as long as TASK_REG_SZ. At least 19 bytes recommended.
* Larger values may improve speed of NoICE memory move commands.)
COMBUF_SIZE EQU 128 DATA SIZE FOR COMM BUFFER
COMBUF RMB 2+COMBUF_SIZE+1 BUFFER ALSO HAS FN, LEN, AND CHECK
*
RAM_END EQU * ADDRESS OF TOP+1 OF RAM
*
*===========================================================================
ORG ROM_START
*
* Power on reset
RESET
*
* Set CPU mode to safe state
ORCC #I+F INTERRUPTS OFF
LDS #MONSTACK CLEAN STACK IS HAPPY STACK
*
*----------------------------------------------------------------------------
*;* IFEQ ROMEM,1
*
* Initialize S16450 UART on ROM emulator
*
* Delay here in case the UART has not come out of reset yet.
LDX #0
LOP LEAX -1,X DELAY FOR SLOW RESETTING UART
NOP
NOP
BNE LOP
*
* access baud generator, no parity, 1 stop bit, 8 data bits
* LDA #$83
* STA S16450+LCR
*
* fixed baud rate of 19200: crystal is 3.686400 Mhz.
* Divisor is 3,686400/(16*baud)
* LDA #12 fix at 19.2 kbaud
* STA S16450+RXR lsb
* LDA #0
* STA S16450+RXR+1 msb=0
*
* access data registers, no parity, 1 stop bits, 8 data bits
* LDA #$03
* STA S16450+LCR
*
* no loopback, OUT2 on, OUT1 on, RTS on, DTR (LED) on
* LDA #$0F
* STA S16450+MCR
*
* disable all interrupts: modem, receive error, transmit, and receive
* LDA #$00
* STA S16450+IER
*
*;* ELSE
*
* Initialize your UART here
LDA #$03 Reset ACIA
STA SER_STATUS
LDA #$11 8 data 2 stop no parity
STA SER_STATUS
TST SER_RXDATA
*;* ENDIF
*
*----------------------------------------------------------------------------
*
* Initialize RAM interrupt vectors
LDY #INT_ENTRY ADDRESS OF DEFAULT HANDLER
LDX #RAMVEC POINTER TO RAM VECTORS
LDB #NVEC NUMBER OF VECTORS
RES10 STY ,X++ SET VECTOR
DECB
BNE RES10
*
* Initialize user registers
LDD #INITSTACK
STA REG_SP+1 INIT USER'S STACK POINTER MSB
STB REG_SP LSB
*
LDD #0
STD REG_PC
STA REG_A
STA REG_B
STA REG_DP
STD REG_X
STD REG_Y
STD REG_U
STA REG_STATE initial state is "RESET"
*
* Initialize memory paging variables and hardware (if any)
STA REG_PAGE initial page is zero
*;;; STA MAPIMG
*;;; STA MAPREG set hardware map
*
LDA #E+I+F state "all regs pushed", no ints
STA REG_CC
*
* Set function code for "GO". Then if we reset after being told to
* GO, we will come back with registers so user can see the crash
LDA #FN_RUN_TARG
STA COMBUF
JMP RETURN_REGS DUMP REGS, ENTER MONITOR
*
*===========================================================================
* Get a character to A
*
* Return A=char, CY=0 if data received
* CY=1 if timeout (0.5 seconds)
*
* Uses 6 bytes of stack including return address
*
GETCHAR
PSHS X
LDX #0 LONG TIMEOUT
GC10 JSR REWDT PREVENT WATCHDOG TIMEOUT
LEAX -1,X
BEQ GC90 EXIT IF TIMEOUT
LDA SER_STATUS READ DEVICE STATUS
ANDA #RXRDY
BEQ GC10 NOT READY YET.
*
* Data received: return CY=0. data in A
CLRA CY=0
LDA SER_RXDATA READ DATA
PULS X,PC
*
* Timeout: return CY=1
GC90 ORCC #C CY=1
PULS X,PC
*
*===========================================================================
* Output character in A
*
* Uses 5 bytes of stack including return address
*
PUTCHAR
PSHS A
PC10 JSR REWDT PREVENT WATCHDOG TIMEOUT
LDA SER_STATUS CHECK TX STATUS
ANDA #TXRDY RX READY ?
BEQ PC10
PULS A
STA SER_TXDATA TRANSMIT CHAR.
RTS
*
*======================================================================
*
* RESET WATCHDOG TIMER. MUST BE CALLED AT LEAST ONCE EVERY LITTLE WHILE
* OR COP INTERRUPT WILL OCCUR
*
* Uses 2 bytes of stack including return address
*
REWDT CLRA
* STA WDT
INCA
* STA WDT CU-style WDT: must leave bit high
RTS
*
*======================================================================
* Response string for GET TARGET STATUS request
* Reply describes target:
TSTG FCB 5 2: PROCESSOR TYPE = 6809
FCB COMBUF_SIZE 3: SIZE OF COMMUNICATIONS BUFFER
FCB 0 4: NO TASKING SUPPORT
FDB 0,0 5-8: LOW AND HIGH LIMIT OF MAPPED MEM (NONE)
FCB B1-B0 9: BREAKPOINT INSTR LENGTH
B0 SWI 10: BREAKPOINT INSTRUCTION
B1 FCC '6809 monitor V1.0' DESCRIPTION, ZERO
FCB 0
TSTG_SIZE EQU *-TSTG SIZE OF STRING
*
*======================================================================
* HARDWARE PLATFORM INDEPENDENT EQUATES AND CODE
*
* Communications function codes.
FN_GET_STAT EQU $FF reply with device info
FN_READ_MEM EQU $FE reply with data
FN_WRITE_M EQU $FD reply with status (+/-)
FN_READ_RG EQU $FC reply with registers
FN_WRITE_RG EQU $FB reply with status
FN_RUN_TARG EQU $FA reply (delayed) with registers
FN_SET_BYTE EQU $F9 reply with data (truncate if error)
FN_IN EQU $F8 input from port
FN_OUT EQU $F7 output to port
*
FN_MIN EQU $F7 MINIMUM RECOGNIZED FUNCTION CODE
FN_ERROR EQU $F0 error reply to unknown op-code
*
*===========================================================================
* Common handler for default interrupt handlers
* Enter with A=interrupt code = processor state
* All registers stacked, PC=next instruction
INT_ENTRY
STA REG_STATE SAVE STATE
*
* Save registers from stack to reg block for return to master
* Host wants least significant bytes first, so flip as necessary
PULS A
STA REG_CC CONDITION CODES
PULS A
STA REG_A A
PULS A
STA REG_B B
PULS A
STA REG_DP DP
PULS D
STA REG_X+1 MSB X
STB REG_X LSB X
PULS D
STA REG_Y+1 MSB Y
STB REG_Y LSB Y
PULS D
STA REG_U+1 MSB U
STB REG_U LSB U
*
* If this is a breakpoint (state = 1), then back up PC to point at SWI
PULS X PC AFTER INTERRUPT
LDA REG_STATE
CMPA #1
BNE NOTBP BR IF NOT A BREAKPOINT
LEAX -1,X ELSE BACK UP TO POINT AT SWI LOCATION
NOTBP TFR X,D TRANSFER PC TO D
STA REG_PC+1 MSB
STB REG_PC LSB
JMP ENTER_MON REG_PC POINTS AT POST-INTERRUPT OPCODE
*
*===========================================================================
* Main loop wait for command frame from master
*
* Uses 6 bytes of stack including return address
*
MAIN LDS #MONSTACK CLEAN STACK IS HAPPY STACK
LDX #COMBUF BUILD MESSAGE HERE
*
* First byte is a function code
JSR GETCHAR GET A FUNCTION (6 bytes of stack)
BCS MAIN JIF TIMEOUT: RESYNC
CMPA #FN_MIN
BLO MAIN JIF BELOW MIN: ILLEGAL FUNCTION
STA ,X+ SAVE FUNCTION CODE
*
* Second byte is data byte count (may be zero)
JSR GETCHAR GET A LENGTH BYTE
BCS MAIN JIF TIMEOUT: RESYNC
CMPA #COMBUF_SIZE
BHI MAIN JIF TOO LONG: ILLEGAL LENGTH
STA ,X+ SAVE LENGTH
CMPA #0
BEQ MA80 SKIP DATA LOOP IF LENGTH = 0
*
* Loop for data
TFR A,B SAVE LENGTH FOR LOOP
MA10 JSR GETCHAR GET A DATA BYTE
BCS MAIN JIF TIMEOUT: RESYNC
STA ,X+ SAVE DATA BYTE
DECB
BNE MA10
*
* Get the checksum
MA80 JSR GETCHAR GET THE CHECKSUM
BCS MAIN JIF TIMEOUT: RESYNC
PSHS A SAVE CHECKSUM
*
* Compare received checksum to that calculated on received buffer
* (Sum should be 0)
JSR CHECKSUM
ADDA ,S+ ADD SAVED CHECKSUM TO COMPUTED
BNE MAIN JIF BAD CHECKSUM
*
* Process the message.
LDX #COMBUF
LDA ,X+ GET THE FUNCTION CODE
LDB ,X+ GET THE LENGTH
CMPA #FN_GET_STAT
BEQ TARGET_STAT
CMPA #FN_READ_MEM
BEQ JREAD_MEM
CMPA #FN_WRITE_M
BEQ JWRITE_MEM
CMPA #FN_READ_RG
BEQ JREAD_REGS
CMPA #FN_WRITE_RG
BEQ JWRITE_REGS
CMPA #FN_RUN_TARG
BEQ JRUN_TARGET
CMPA #FN_SET_BYTE
BEQ JSET_BYTES
CMPA #FN_IN
BEQ JIN_PORT
CMPA #FN_OUT
BEQ JOUT_PORT
*
* Error: unknown function. Complain
LDA #FN_ERROR
STA COMBUF SET FUNCTION AS "ERROR"
LDA #1
JMP SEND_STATUS VALUE IS "ERROR"
*
* long jumps to handlers
JREAD_MEM JMP READ_MEM
JWRITE_MEM JMP WRITE_MEM
JREAD_REGS JMP READ_REGS
JWRITE_REGS JMP WRITE_REGS
JRUN_TARGET JMP RUN_TARGET
JSET_BYTES JMP SET_BYTES
JIN_PORT JMP IN_PORT
JOUT_PORT JMP OUT_PORT
*===========================================================================
*
* Target Status: FN, len
*
* Entry with A=function code, B=data size, X=COMBUF+2
*
TARGET_STAT
LDX #TSTG DATA FOR REPLY
LDY #COMBUF+1 POINTER TO RETURN BUFFER
LDB #TSTG_SIZE LENGTH OF REPLY
STB ,Y+ SET SIZE IN REPLY BUFFER
TS10 LDA ,X+ MOVE REPLY DATA TO BUFFER
STA ,Y+
DECB
BNE TS10
*
* Compute checksum on buffer, and send to master, then return
JMP SEND
*===========================================================================
*
* Read Memory: FN, len, page, Alo, Ahi, Nbytes
*
* Entry with A=function code, B=data size, X=COMBUF+2
*
READ_MEM
*
* Set map
*;;; LDA 0,X
*;;; STA MAPIMG
*;;; STA MAPREG
*
* Get address
LDA 2,X MSB OF ADDRESS IN A
LDB 1,X LSB OF ADDRESS IN B
TFR D,Y ADDRESS IN Y
*
* Prepare return buffer: FN (unchanged), LEN, DATA
LDB 3,X NUMBER OF BYTES TO RETURN
STB COMBUF+1 RETURN LENGTH = REQUESTED DATA
BEQ GLP90 JIF NO BYTES TO GET
*
* Read the requested bytes from local memory
GLP LDA ,Y+ GET BYTE
STA ,X+ STORE TO RETURN BUFFER
DECB
BNE GLP
*
* Compute checksum on buffer, and send to master, then return
GLP90 JMP SEND
*===========================================================================
*
* Write Memory: FN, len, page, Alo, Ahi, (len-3 bytes of Data)
*
* Entry with A=function code, B=data size, X=COMBUF+2
*
* Uses 6 bytes of stack
*
WRITE_MEM
*
* Set map
LDA ,X+
*;;; STA MAPIMG
*;;; STA MAPREG
*
* Get address
LDB ,X+ LSB OF ADDRESS IN B
LDA ,X+ MSB OF ADDRESS IN A
TFR D,Y ADDRESS IN Y
*
* Compute number of bytes to write
LDB COMBUF+1 NUMBER OF BYTES TO RETURN
SUBB #3 MINUS PAGE AND ADDRESS
BEQ WLP50 JIF NO BYTES TO PUT
*
* Write the specified bytes to local memory
PSHS B,X,Y
WLP LDA ,X+ GET BYTE TO WRITE
STA ,Y+ STORE THE BYTE AT ,Y
DECB
BNE WLP
*
* Compare to see if the write worked
PULS B,X,Y
WLP20 LDA ,X+ GET BYTE JUST WRITTEN
CMPA ,Y+
BNE WLP80 BR IF WRITE FAILED
DECB
BNE WLP20
*
* Write succeeded: return status = 0
WLP50 LDA #0 RETURN STATUS = 0
BRA WLP90
*
* Write failed: return status = 1
WLP80 LDA #1
* Return OK status
WLP90 JMP SEND_STATUS
*===========================================================================
*
* Read registers: FN, len=0
*
* Entry with A=function code, B=data size, X=COMBUF+2
*
READ_REGS
*
* Enter here from SWI after "RUN" and "STEP" to return task registers
RETURN_REGS
LDY #TASK_REGS POINTER TO REGISTERS
LDB #TASK_REG_SZ NUMBER OF BYTES
LDX #COMBUF+1 POINTER TO RETURN BUFFER
STB ,X+ SAVE RETURN DATA LENGTH
*
* Copy the registers
GRLP LDA ,Y+ GET BYTE TO A
STA ,X+ STORE TO RETURN BUFFER
DECB
BNE GRLP
*
* Compute checksum on buffer, and send to master, then return
JMP SEND
*===========================================================================
*
* Write registers: FN, len, (register image)
*
* Entry with A=function code, B=data size, X=COMBUF+2
*
WRITE_REGS
*
TSTB NUMBER OF BYTES
BEQ WRR80 JIF NO REGISTERS
*
* Copy the registers
LDY #TASK_REGS POINTER TO REGISTERS
WRRLP LDA ,X+ GET BYTE TO A
STA ,Y+ STORE TO REGISTER RAM
DECB
BNE WRRLP
*
* Return OK status
WRR80 CLRA
JMP SEND_STATUS
*===========================================================================
*
* Run Target: FN, len
*
* Entry with A=function code, B=data size, X=COMBUF+2
*
RUN_TARGET
*
* Restore user's map
** LDA REG_PAGE USER'S PAGE
** STA MAPIMG SET IMAGE
** STA MAPREG SET MAPPING REGISTER
*
* Switch to user stack
LDA REG_SP+1 BACK TO USER STACK
LDB REG_SP
TFR D,S TO S
*
* Restore registers
LDA REG_PC+1 MS USER PC FOR RTI
LDB REG_PC LS USER PC FOR RTI
PSHS D
*
LDA REG_U+1
LDB REG_U
PSHS D
*
LDA REG_Y+1
LDB REG_Y
PSHS D
*
LDA REG_X+1
LDB REG_X
PSHS D
*
LDA REG_DP
PSHS A
*
LDA REG_B
PSHS A
*
LDA REG_A
PSHS A
*
LDA REG_CC SAVE USER CONDITION CODES FOR RTI
ORA #E _MUST_ BE "ALL REGS PUSHED"
PSHS A
*
* Return to user
RTI
*
*===========================================================================
*
* Common continue point for all monitor entrances
* SP = user stack
ENTER_MON
TFR S,D USER STACK POINTER
STA REG_SP+1 SAVE USER'S STACK POINTER (MSB)
STB REG_SP LSB
*
* Change to our own stack
LDS #MONSTACK AND USE OURS INSTEAD
*
* Operating system variables
** LDA MAPIMG GET CURRENT USER MAP
LDA #0 ... OR ZERO IF UNMAPPED TARGET
STA REG_PAGE SAVE USER'S PAGE
*
* Return registers to master
JMP RETURN_REGS
*===========================================================================
*
* Set target byte(s): FN, len { (page, alow, ahigh, data), (...)... }
*
* Entry with A=function code, B=data size, X=COMBUF+2
*
* Return has FN, len, (data from memory locations)
*
* If error in insert (memory not writable), abort to return short data
*
* This function is used primarily to set and clear breakpoints
*
* Uses 1 byte of stack
*
SET_BYTES
LDU #COMBUF+1 POINTER TO RETURN BUFFER
LDA #0
STA ,U+ SET RETURN COUNT AS ZERO
LSRB
LSRB LEN/4 = NUMBER OF BYTES TO SET
BEQ SB99 JIF NO BYTES (COMBUF+1 = 0)
*
* Loop on inserting bytes
SB10 PSHS B SAVE LOOP COUNTER
*
* Set map
*;;; LDA 0,X
*;;; STA MAPIMG
*;;; STA MAPREG
*
* Get address
LDA 2,X MSB OF ADDRESS IN A
LDB 1,X LSB OF ADDRESS IN B
TFR D,Y MEMORY ADDRESS IN Y
*
* Read current data at byte location
LDA 0,Y
*
* Insert new data at byte location
LDB 3,X GET BYTE TO STORE
STB 0,Y WRITE TARGET MEMORY
*
* Verify write
CMPB 0,Y READ TARGET MEMORY
PULS B RESTORE LOOP COUNT, CC'S INTACT
BNE SB90 BR IF INSERT FAILED: ABORT
*
* Save target byte in return buffer
STA ,U+
INC COMBUF+1 COUNT ONE RETURN BYTE
*
* Loop for next byte
LEAX 4,X STEP TO NEXT BYTE SPECIFIER
CMPB COMBUF+1
BNE SB10 *LOOP FOR ALL BYTES
*
* Return buffer with data from byte locations
SB90
*
* Compute checksum on buffer, and send to master, then return
SB99 JMP SEND
*===========================================================================
*
* Input from port: FN, len, PortAddressLo, PAhi (=0)
*
* While the 6809 has no input or output instructions, we retain these
* to allow write-without-verify
*
* Entry with A=function code, B=data size, X=COMBUF+2
*
IN_PORT
*
* Get port address
LDA 1,X MSB OF ADDRESS IN A
LDB 0,X LSB OF ADDRESS IN B
TFR D,Y MEMORY ADDRESS IN Y
*
* Read the requested byte from local memory
LDA 0,Y
*
* Return byte read as "status"
JMP SEND_STATUS
*===========================================================================
*
* Output to port FN, len, PortAddressLo, PAhi (=0), data
*
* Entry with A=function code, B=data size, X=COMBUF+2
*
OUT_PORT
*
* Get port address
LDA 1,X MSB OF ADDRESS IN A
LDB 0,X LSB OF ADDRESS IN B
TFR D,Y MEMORY ADDRESS IN Y
*
* Get data
LDA 2,X
*
* Write value to port
STA 0,Y
*
* Do not read port to verify (some I/O devices don't like it)
*
* Return status of OK
CLRA
JMP SEND_STATUS
*===========================================================================
* Build status return with value from "A"
*
SEND_STATUS
STA COMBUF+2 SET STATUS
LDA #1
STA COMBUF+1 SET LENGTH
BRA SEND
*===========================================================================
* Append checksum to COMBUF and send to master
*
SEND JSR CHECKSUM GET A=CHECKSUM, X->checksum location
NEGA
STA 0,X STORE NEGATIVE OF CHECKSUM
*
* Send buffer to master
LDX #COMBUF POINTER TO DATA
LDB 1,X LENGTH OF DATA
ADDB #3 PLUS FUNCTION, LENGTH, CHECKSUM
SND10 LDA ,X+
JSR PUTCHAR SEND A BYTE
DECB
BNE SND10
JMP MAIN BACK TO MAIN LOOP
*===========================================================================
* Compute checksum on COMBUF. COMBUF+1 has length of data,
* Also include function byte and length byte
*
* Returns:
* A = checksum
* X = pointer to next byte in buffer (checksum location)
* B is scratched
*
CHECKSUM
LDX #COMBUF pointer to buffer
LDB 1,X length of message
ADDB #2 plus function, length
LDA #0 init checksum to 0
CHK10 ADDA ,X+
DECB
BNE CHK10 loop for all
RTS return with checksum in A
***********************************************************************
*
* Interrupt handlers to catch unused interrupts and traps
* Registers are stacked. Jump through RAM vector using X, type in A
*
* This will affect only interrupt routines looking for register values!
*
* Our default handler uses the code in "A" as the processor state to be
* passed back to the host.
*
RES_ENT LDA #7
LDX RAMVEC+0
JMP 0,X
*
SWI3_ENT LDA #6
LDX RAMVEC+2
JMP 0,X
*
SWI2_ENT LDA #5
LDX RAMVEC+4
JMP 0,X
*
* May have only PC and CC's pushed (unless we were waiting for an interrupt)
* Push all registers here for common entry (else we can't use our RAM vector)
FIRQ_ENT STA REG_A SAVE A REG
PULS A GET CC'S FROM STACK
BITA #E
BNE FIRQ9 BR IF ALL REGISTERS PUSHED ALREADY
PSHS U,Y,X,DP,B ELSE PUSH THEM NOW
LDB REG_A
PSHS B
ORA #E SET AS "ALL REGS PUSHED"
FIRQ9 PSHS A REPLACE CC'S
LDA #4
LDX RAMVEC+6
JMP 0,X
*
IRQ_ENT LDA #3
LDX RAMVEC+8
JMP 0,X
*
NMI_ENT LDA #2
LDX RAMVEC+12
JMP 0,X
*
SWI_ENT LDA #1
JMP INT_ENTRY
*
*============================================================================
* VECTORS THROUGH RAM
ORG HARD_VECT
FDB RES_ENT fff0 (reserved)
FDB SWI3_ENT fff2 (SWI3)
FDB SWI2_ENT fff4 (SWI2)
FDB FIRQ_ENT fff6 (FIRQ)
FDB IRQ_ENT fff8 (IRQ)
FDB SWI_ENT fffa (SWI/breakpoint)
FDB NMI_ENT fffc (NMI)
FDB RESET fffe reset
*
END RESET
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