; This must be the *first* file on the linker command line
;
- .export _exit
- .import zerobss
- .import initlib, donelib
- .import callmain, callirq
- .import COUT
- .import __STARTUP_LOAD__, __BSS_LOAD__ ; Linker generated
- .import __INTERRUPTOR_COUNT__ ; Linker generated
+ .export _exit
+ .import zerobss
+ .import initlib, donelib
+ .import callmain, callirq
+ .import COUT
+ .import __STARTUP_LOAD__, __BSS_LOAD__ ; Linker generated
+ .import __INTERRUPTOR_COUNT__ ; Linker generated
.include "zeropage.inc"
- .include "apple2.inc"
- .include "mli.inc"
+ .include "apple2.inc"
+ .include "mli.inc"
; ------------------------------------------------------------------------
- .segment "EXEHDR"
+ .segment "EXEHDR"
- .addr __STARTUP_LOAD__ ; Start address
- .word __BSS_LOAD__ - __STARTUP_LOAD__ ; Size
+ .addr __STARTUP_LOAD__ ; Start address
+ .word __BSS_LOAD__ - __STARTUP_LOAD__ ; Size
; ------------------------------------------------------------------------
- .segment "STARTUP"
+ .segment "STARTUP"
; ProDOS TechRefMan, chapter 5.2.1:
; "For maximum interrupt efficiency, a system program should not
; use more than the upper 3/4 of the stack."
- ldx #$FF
- txs ; Init stack pointer
+ ldx #$FF
+ txs ; Init stack pointer
; Delegate all further processing to keep STARTUP small
- jsr init
+ jsr init
; Avoid re-entrance of donelib. This is also the _exit entry
-_exit: ldx #<exit
- lda #>exit
- jsr reset ; Setup RESET vector
+_exit: ldx #<exit
+ lda #>exit
+ jsr reset ; Setup RESET vector
; Check for valid interrupt vector table entry number
lda intnum
- beq :+
+ beq :+
; Deallocate interrupt vector table entry
- dec params ; Adjust parameter count
- jsr ENTRY
- .byte $41 ; Dealloc interrupt
- .addr params
+ dec params ; Adjust parameter count
+ jsr ENTRY
+ .byte $41 ; Dealloc interrupt
+ .addr params
; Call module destructors
-: jsr donelib
+: jsr donelib
; Restore the original RESET vector
-exit: ldx #$02
-: lda rvsave,x
- sta SOFTEV,x
+exit: ldx #$02
+: lda rvsave,x
+ sta SOFTEV,x
dex
- bpl :-
+ bpl :-
; Copy back the zero page stuff
- ldx #zpspace-1
-: lda zpsave,x
- sta sp,x
+ ldx #zpspace-1
+: lda zpsave,x
+ sta sp,x
dex
- bpl :-
+ bpl :-
; ProDOS TechRefMan, chapter 5.2.1:
; "System programs should set the stack pointer to $FF at the
; warm-start entry point."
- ldx #$FF
- txs ; Re-init stack pointer
+ ldx #$FF
+ txs ; Re-init stack pointer
; Back to DOS
- jmp DOSWARM
+ jmp DOSWARM
; ------------------------------------------------------------------------
- .segment "INIT"
+ .segment "INIT"
; Save the zero page locations we need
-init: ldx #zpspace-1
-: lda sp,x
- sta zpsave,x
+init: ldx #zpspace-1
+: lda sp,x
+ sta zpsave,x
dex
- bpl :-
+ bpl :-
; Save the original RESET vector
- ldx #$02
-: lda SOFTEV,x
- sta rvsave,x
+ ldx #$02
+: lda SOFTEV,x
+ sta rvsave,x
dex
- bpl :-
+ bpl :-
; ProDOS TechRefMan, chapter 5.3.5:
; "Your system program should place in the RESET vector the
; address of a routine that ... closes the files."
- ldx #<_exit
- lda #>_exit
- jsr reset ; Setup RESET vector
+ ldx #<_exit
+ lda #>_exit
+ jsr reset ; Setup RESET vector
; Clear the BSS data
- jsr zerobss
+ jsr zerobss
; Setup the stack
- lda HIMEM
- sta sp
- lda HIMEM+1
- sta sp+1 ; Set argument stack ptr
+ lda HIMEM
+ sta sp
+ lda HIMEM+1
+ sta sp+1 ; Set argument stack ptr
; Call module constructors
- jsr initlib
+ jsr initlib
; Check for interruptors
lda #<__INTERRUPTOR_COUNT__
- beq :+
+ beq :+
; Check for ProDOS
- lda ENTRY
- cmp #$4C ; Is MLI present? (JMP opcode)
- bne prterr
+ lda ENTRY
+ cmp #$4C ; Is MLI present? (JMP opcode)
+ bne prterr
; Allocate interrupt vector table entry
- jsr ENTRY
- .byte $40 ; Alloc interrupt
- .addr params
- bcs prterr
+ jsr ENTRY
+ .byte $40 ; Alloc interrupt
+ .addr params
+ bcs prterr
; Push arguments and call main()
-: jmp callmain
+: jmp callmain
; Print error message and return
-prterr: ldx #msglen-1
-: lda errmsg,x
- jsr COUT
+prterr: ldx #msglen-1
+: lda errmsg,x
+ jsr COUT
dex
- bpl :-
+ bpl :-
rts
errmsg: .ifdef __APPLE2ENH__
- .byte $8D, 't'|$80, 'p'|$80, 'u'|$80, 'r'|$80, 'r'|$80
- .byte 'e'|$80, 't'|$80, 'n'|$80, 'i'|$80, ' '|$80, 'c'|$80
- .byte 'o'|$80, 'l'|$80, 'l'|$80, 'a'|$80, ' '|$80, 'o'|$80
- .byte 't'|$80, ' '|$80, 'd'|$80, 'e'|$80, 'l'|$80, 'i'|$80
- .byte 'a'|$80, 'F'|$80, $8D
+ .byte $8D, 't'|$80, 'p'|$80, 'u'|$80, 'r'|$80, 'r'|$80
+ .byte 'e'|$80, 't'|$80, 'n'|$80, 'i'|$80, ' '|$80, 'c'|$80
+ .byte 'o'|$80, 'l'|$80, 'l'|$80, 'a'|$80, ' '|$80, 'o'|$80
+ .byte 't'|$80, ' '|$80, 'd'|$80, 'e'|$80, 'l'|$80, 'i'|$80
+ .byte 'a'|$80, 'F'|$80, $8D
.else
- .byte $8D, 'T'|$80, 'P'|$80, 'U'|$80, 'R'|$80, 'R'|$80
- .byte 'E'|$80, 'T'|$80, 'N'|$80, 'I'|$80, ' '|$80, 'C'|$80
- .byte 'O'|$80, 'L'|$80, 'L'|$80, 'A'|$80, ' '|$80, 'O'|$80
- .byte 'T'|$80, ' '|$80, 'D'|$80, 'E'|$80, 'L'|$80, 'I'|$80
- .byte 'A'|$80, 'F'|$80, $8D
+ .byte $8D, 'T'|$80, 'P'|$80, 'U'|$80, 'R'|$80, 'R'|$80
+ .byte 'E'|$80, 'T'|$80, 'N'|$80, 'I'|$80, ' '|$80, 'C'|$80
+ .byte 'O'|$80, 'L'|$80, 'L'|$80, 'A'|$80, ' '|$80, 'O'|$80
+ .byte 'T'|$80, ' '|$80, 'D'|$80, 'E'|$80, 'L'|$80, 'I'|$80
+ .byte 'A'|$80, 'F'|$80, $8D
.endif
msglen = * - errmsg
; ------------------------------------------------------------------------
- .segment "LOWCODE"
+ .segment "LOWCODE"
; ProDOS TechRefMan, chapter 6.2:
- ; "Each installed routine must begin with a CLD instruction"
+ ; "Each installed routine must begin with a CLD instruction."
intrpt: cld
- ; Call interruptors
- jsr callirq
+ ; Call interruptors and check for success
+ jsr callirq
+ bcc :+
; ProDOS TechRefMan, chapter 6.2:
; "When the routine that can process the interrupt is called, it
clc
rts
+ ; ProDOS TechRefMan, chapter 6.2:
+ ; "When a routine that cannot process the interrupt is called,
+ ; it should return (via an RTS) with the cary flag set ..."
+: sec
+ rts
+
; ------------------------------------------------------------------------
.code
; Setup RESET vector
-reset: stx SOFTEV
- sta SOFTEV+1
- eor #$A5
- sta PWREDUP
+reset: stx SOFTEV
+ sta SOFTEV+1
+ eor #$A5
+ sta PWREDUP
rts
; ------------------------------------------------------------------------
.data
-zpsave: .res zpspace
+zpsave: .res zpspace
-rvsave: .res 3
+rvsave: .res 3
-params: .byte $02 ; Parameter count
-intnum: .byte $00 ; Interrupt number
- .addr intrpt ; Interrupt handler
+params: .byte $02 ; Parameter count
+intnum: .byte $00 ; Interrupt number
+ .addr intrpt ; Interrupt handler
\ No newline at end of file
projects / cc65 / commitdiff