Startup code
Revision as of 11:42, 23 February 2020 by Bzuidgeest (talk | contribs)
The startup code
I cannot add the asm code as a file to the wiki. So I pasted it below. I hope the it survives the wiki formatting.
; File: fxloader.asm
; 05/14/2004
PW 128 ;Page Width (# of char/line)
PL 60 ;Page Length for HP Laser
INCLIST ON ;Add Include files in Listing
;*********************************************
;Test for Valid Processor defined in -D option
;*********************************************
IF USING_265
ELSEIF USING_816
ELSEIF USING_CDC16F
ELSE
EXIT "Not Valid Processor: Use -DUSING_816, etc. ! ! ! ! ! ! ! ! ! ! ! !"
ENDIF
;*********************************************
;Test for Valid 'Model' type defined in -D option
;*********************************************
IF SMALL
ELSEIF MEDIUM
ELSEIF COMPACT
ELSEIF LARGE
ELSE
EXIT "Not Valid 'Model' type - SMALL, MEDIUM, COMPACT, or LARGE: Use -DSMALL, etc. ! ! ! ! ! ! ! ! ! ! ! !"
ENDIF
title "fxos 'C' Startup Program V 1.00 for Large Model W65C816 - fxloader.asm"
; bgnpkhdr
;***************************************************************************
; FILE_NAME: WDC_CStartup_816.asm
;
; DATA_RIGHTS: Western Design Center and R & C Services Proprietary
; Copyright(C) 1980-2003
; All rights reserved. Reproduction in any manner,
; in whole or in part, is strictly prohibited without
; the prior written approval of R & C Services or
; Western Design Center.
;
; Information contained in this publication regarding
; device applications and the like is intended through
; suggestion only and may be superseded by updates.
; It is your responsibility to ensure that your application
; meets with your specifications. No representation or
; warranty is given and no liability is assumed by
; Western Design Center, Inc. with respect to the accuracy
; or use of such information, or infringement of patents
; or other intellectual property rights arising from such
; use or otherwise. Use of Western Design Center's products
; as critical components in life support systems is not
; authorized except with express written approval by
; Western Design Center, Inc.'s. No licenses are conveyed,
; implicitly or otherwise, under any intellectual property rights.
;
;
;
; TITLE: WDC_CStartup_816
;
; DESCRIPTION: This File describes the WDC SDS General purpose ROM startup code.
;
; Program Flow
;
; First we make sure we are in native mode.
; Then we set up the stack pointer.
; Then we set the data bank register.
; Then we copy the initialized data.
; Then we clear out the uninitialized data.
; Then we call main.
;
; DEFINED FUNCTIONS:
; Undefined_IRQ
; - Process a Bad Interrupt Vector - send code & Hang!
;
;
; SPECIAL_CONSIDERATIONS:
;
;
; SHARED_DATA:
; None
;
; GLOBAL_MODULES:
; None
;
; LOCAL_MODULES:
; See above in "DEFINED FUNCTIONS"
;
; AUTHOR: Jim Goodnow II
;
; CREATION DATE: March 11,1997
;
; REVISION HISTORY
; Name Date Description
; ------------ ---------- ------------------------------------------------
; R. Greenthal 10/07/2003 1.01 Initial
;
;
;
; NOTE:
; Change the lines for each version - current version is 1.01
; See -
; title "WDC 'C' Startup Program V 1.01 for Large Model W65C816 - WDC_CStartup_816.asm"
;
;
;***************************************************************************
;endpkhdr
;***************************************************************************
; Include Files
;***************************************************************************
;None
; Set 8-bit accumulator
setas .macro
SEP #$20 ; set A short
LONGA OFF
.endm
; Set 16-bit accumulator
setal .macro
REP #$20 ; set A long
LONGA ON
.endm
;***************************************************************************
; Global Modules
;***************************************************************************
;None
;***************************************************************************
; External Modules
;***************************************************************************
;None
;***************************************************************************
; External Variables
;***************************************************************************
;None
;***************************************************************************
; Local Constants
;***************************************************************************
;
; .page
;***************************************************************************
; RAM Section
;***************************************************************************
;
sttl "WDC_CStartup_816 Code"
.page
;***************************************************************************
;***************************************************************************
; WDC_CStartup_816 Code Section
;***************************************************************************
;***************************************************************************
****************************************************************
* *
* Define a special section in case most of the *
* code is not in bank 0. *
* *
****************************************************************
; Large Model Function Calls use module Function_Name and xdef ~~Function_Name
STACK EQU $EF00 ;CHANGE THIS FOR YOUR SYSTEM
STARTUP SECTION OFFSET $7D00
~~START:
START:
SEI
CLC ;clear carry
XCE ;clear emulation-Now in Native 16 bit Mode
REP #$38 ;16 bit registers and Clear Decimal mode
LONGI ON
LONGA ON
LDA #STACK ;get the stack address
TCS ;and set the stack to it
****************************************************************
* *
* Set up the data bank register. We assume that the data *
* section is where we want to point at. *
* *
****************************************************************
SEP #$20 ;8 bit accum
LONGA OFF
LDA #^_BEG_DATA ;get bank of data
PHA
PLB ;set data bank register
REP #$20 ;back to 16 bit mode
LONGA ON
****************************************************************
* *
* Next, we want to copy the initialized data from *
* ROM to RAM. *
* *
****************************************************************
LDA #_END_DATA-_BEG_DATA ;number of bytes to copy
BEQ SKIP ;if none, just skip
DEC A ;less one for MVN instruction
LDX #<_ROM_BEG_DATA ;get source into X
LDY #<_BEG_DATA ;get dest into Y
MVN #^_ROM_BEG_DATA,#^_BEG_DATA ;copy bytes
SKIP:
****************************************************************
* *
* Now, clear out the uninitialized data area. *
* We assume that it is in the same bank as DATA. *
* *
****************************************************************
LDX #_END_UDATA-_BEG_UDATA ;get number of bytes to clear
BEQ DONE ;nothing to do
LDA #0 ;get a zero for storing
SEP #$20 ;do byte at a time
LDY #_BEG_UDATA ;get beginning of zeros
LOOP STA |0,Y ;clear memory
INY ;bump pointer
DEX ;decrement count
BNE LOOP ;continue till done
REP #$20 ;16 bit memory reg
DONE:
****************************************************************
* *
* Finally, transfer control to the real program. *
* *
****************************************************************
; Small Model Function Calls use module Function_Name and xdef __Function_Name
; Medium Model Function Calls use module Function_Name and xdef ~_Function_Name
; Large Model Function Calls use module Function_Name and xdef ~~Function_Name
; Compact Model Function Calls use module Function_Name and xdef _~Function_Name
NOP
NOP
XREF ~~main ;change MYSTART to yours
JSL ~~main ;long jump in case not bank 0
XDEF ~~_exit
~~_exit:
BRK
sttl "WDC_CStartup_816 IRQ - Interrupt Handler Code"
.page
;***************************************************************
; *
; Example of transfering control to the real Interrupt *
; Handler written in 'C'. Note: save all the registers *
; *
;***************************************************************
XDEF IRQ
IRQ:
setal
;Example of needing to read/write to data in another data bank
phb ; save Data Bank
phd ; save Direct Page Register
pha
phx
phy
setas
;LDA #'A'
;STA >$AFA000
setal
XREF ~~IRQHandler
jsl ~~IRQHandler
;setas
;LDA #'B'
;STA >$AFA000
setal
ply
plx
pla
pld ; restore Direct Page Reg
plb ; Restore Data Bank
RTI
NMI:
RTI
BRK:
setal
;Example of needing to read/write to data in another data bank
phb ; save Data Bank
phd ; save Direct Page Register
pha
phx
phy
setas
setal
XREF ~~BRKHandler
jsl ~~BRKHandler
setal
ply
plx
pla
pld ; restore Direct Page Reg
plb ; Restore Data Bank
RTI
COP:
setal
;Example of needing to read/write to data in another data bank
phb ; save Data Bank
phd ; save Direct Page Register
pha
phx
phy
setas
setal
XREF ~~COPHandler
jsl ~~COPHandler
setal
ply
plx
pla
pld ; restore Direct Page Reg
plb ; Restore Data Bank
RTI
;************************************************
; Bad Vectors
;************************************************
Undefined_IRQ:
nop
bra Undefined_IRQ
;WDCMON_START EQU $7E00
;ROMSPACE EQU WDCMON_START-* ;gives space left in the ROM BEFORE TABLES;
; IF ROMSPACE<0
;EXIT "Not Enough Memory for WDC_Cstartup_02.ASM - bumping into WDCMON! ! ! ! ! ! ! ! ! ! ! !"
;ENDIF
; ENDS
XREF _BEG_DATA
XREF _END_DATA
XREF _ROM_BEG_DATA
XREF _BEG_UDATA
XREF _END_UDATA
ends
sttl "WDC_CStartup_816 Shadow Vector Defines"
.page
;***************************************************************************
; $7E00 - $7FFF New Expanded Shadow Vector Section Definitions
;***************************************************************************
;***************************************************************************
;***************************************************************************
; hvectors: section ; the real reset and interrupt vectors
;
; ;65C816 Vectors
; org $18ffe4
; ;Status bit E = 0 (Native mode);
; dw Undefined_IRQ ; $FFE4 - COP(816)
; dw Undefined_IRQ ; $FFE6 - BRK(816)
; dw Undefined_IRQ ; $FFE8 - ABORT(816)
; dw Undefined_IRQ ; $FFEA - NMI(816)
; dw Undefined_IRQ ; $FFEC - IRQRVD(816)
; dw IRQ ; $FFEE - IRQ(816)
; ;Status bit E = 1 (Emulation mode)
; dw Undefined_IRQ ; $FFF0 - IRQRVD(816)
; dw Undefined_IRQ ; $FFF2 - IRQRVD(816)
; dw Undefined_IRQ ; $FFF4 - COP(816Emulation)
; dw Undefined_IRQ ; $FFF6 - IRQRVD(816Emulation)
; dw Undefined_IRQ ; $FFF8 - ABORT(816Emulation)
;
; ; Common Vectors for all CPUs
; dw Undefined_IRQ ; $FFFA - NMIRQ (ALL)
; dw START ; $FFFC - RESET (ALL)
; dw Undefined_IRQ ; $FFFE - IRQBRK (ALL)
;
; ends
****************************************************************
* *
* This section defines the interrupt and reset vectors. *
* The reset vectors always start at FFE4 in bank 0. *
* Since the vectors are only 16 bits, they must point *
* into bank 0. Replace the "Undefined_IRQ" with any *
* routines that handle that interrupt. *
* *
****************************************************************
vectors: section ; the real reset and interrupt vectors
;65C816 Vectors
org $ffe4
;Status bit E = 0 (Native mode)
dw COP ; $FFE4 - COP(816)
dw BRK ; $FFE6 - BRK(816)
dw Undefined_IRQ ; $FFE8 - ABORT(816)
dw NMI ; $FFEA - NMI(816)
dw Undefined_IRQ ; $FFEC - IRQRVD(816)
dw IRQ ; $FFEE - IRQ(816)
;Status bit E = 1 (Emulation mode)
dw Undefined_IRQ ; $FFF0 - IRQRVD(816)
dw Undefined_IRQ ; $FFF2 - IRQRVD(816)
dw Undefined_IRQ ; $FFF4 - COP(816Emulation)
dw Undefined_IRQ ; $FFF6 - IRQRVD(816Emulation)
dw Undefined_IRQ ; $FFF8 - ABORT(816Emulation)
; Common Vectors for all CPUs
dw Undefined_IRQ ; $FFFA - NMIRQ (ALL)
dw START ; $FFFC - RESET (ALL)
dw Undefined_IRQ ; $FFFE - IRQBRK (ALL)
ends
end
;**********************************************************************
; End of WDC_CSTARTUP_C.ASM
;**********************************************************************
